KX Riders
Maintenance & Technical => KX250 / KX125 => Topic started by: dinkyguitar on November 11, 2014, 10:58:07 AM
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Well, I haven't been able to start my 87 KX 250 since the weather changed.
I'm actually regretting having it since it's been giving me starting problems.
All my hard work down the drain since I can't start it.
Not sure what this means but, twice I took the exhaust pipe off and dumped 1/2 cup of looks like black fuel out of it
Definitely gas...my coolant is still there as well as my crankcase.
She has a good blue spark, and wet when I take it out.
Last time I dumped the pipe, I also flipped the bike over and spun the back tire. Maybe a teaspoon of this black stuff came out.
Today I dumped the pipe again, kicked it over, and I heard a small backfire in the pipe...almost like a fizz..
I'm using Amsoil 32:1....could this be bad fuel? I've had it for about 4 weeks..using 93 octane.
Can't seem to figure it out...and it gets me pissed when I see other bikes start 1 or second kick.
All I can say is that this sucks and is really taking me over.
dinky,
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if you are mixing Amsoil @ 32:1 you may as well pour the oil straight in the gas tank. Each oil manufacturer has their own mix ratio. What the factory recommends is based on if you are running factory oil. All that aside, it sounds like your needle and seat in your carb need some love, letting fuel keep running in your carb and never shut off. Have you checked your reeds? It can let extra fuel in that you don't want and cause too much fuel to dump in and you would kick the crap out of it or pull start it to get it going.
Good luck, try 50:1 on your Amsoil, it will burn much better.
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if you are mixing Amsoil @ 32:1 you may as well pour the oil straight in the gas tank. Each oil manufacturer has their own mix ratio. What the factory recommends is based on if you are running factory oil. All that aside, it sounds like your needle and seat in your carb need some love, letting fuel keep running in your carb and never shut off. Have you checked your reeds? It can let extra fuel in that you don't want and cause too much fuel to dump in and you would kick the crap out of it or pull start it to get it going.
Good luck, try 50:1 on your Amsoil, it will burn much better.
Thanks,
Just a little back ground. The needle and seat are new. I held the floats by hand and watched for leaks. I also checked the petcock and it's not leaking either. The reeds are new, and I checked to make sure there's no air gaps.
I do have a question....is it normal to hear hissing noises coming from the carb when you spin the flywheel by hand? Seems like air is getting blown back through the carb into the air box....and by spinning the flywheel I mean after the compression stroke when the piston is at BDT.
dinky,
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this noises are normal... what you hear is the piston soaking air/fuel-mixture through the carb ...
hmm.. every time, you had this amount of fuel in the crankcase?? make sure, that the float valve in the carb willl be closed, when the fuel level is reached ...
whats your actual jetting?
and you said the crankcasefuel is black, when you drain it out? ... that sounds like gearbox-oil in my opinion
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this noises are normal... what you hear is the piston soaking air/fuel-mixture through the carb ...
hmm.. every time, you had this amount of fuel in the crankcase?? make sure, that the float valve in the carb willl be closed, when the fuel level is reached ...
whats your actual jetting?
and you said the crankcasefuel is black, when you drain it out? ... that sounds like gearbox-oil in my opinion
The fuel in the exhaust and crankcase only started when I couldn't get the bike running....When it was running in the summer (really just breaking it in after the rebuild) I didn't have this problem. Once the weather got cold is when I couldn't start it any more and I kept trying but it just didn't start. I think last week after I dumped the black fuel from the pipe I was able to start it...and it idled normal.
Mind you I never really got a chance to ride it since my yard is small....never got out of 1st and never ridden longer than 15 minutes.
Jetting was 350 main, 45 pilot. Today I set the float and changed pilot to 42.5 and main to 330.
I always check the gear box oil and it's as full as I filled it. Does seems to be missing any.
Like I said....it all started once it started getting colder.....
dinky,
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this noises are normal... what you hear is the piston soaking air/fuel-mixture through the carb ...
hmm.. every time, you had this amount of fuel in the crankcase?? make sure, that the float valve in the carb willl be closed, when the fuel level is reached ...
whats your actual jetting?
and you said the crankcasefuel is black, when you drain it out? ... that sounds like gearbox-oil in my opinion
The fuel in the exhaust and crankcase only started when I couldn't get the bike running....When it was running in the summer (really just breaking it in after the rebuild) I didn't have this problem. Once the weather got cold is when I couldn't start it any more and I kept trying but it just didn't start. I think last week after I dumped the black fuel from the pipe I was able to start it...and it idled normal.
Mind you I never really got a chance to ride it since my yard is small....never got out of 1st and never ridden longer than 15 minutes.
Jetting was 350 main, 45 pilot. Today I set the float and changed pilot to 42.5 and main to 330.
I always check the gear box oil and it's as full as I filled it. Does seems to be missing any.
Like I said....it all started once it started getting colder.....
dinky,
take a larger pilot jet to get richer ... by cold weather is more oxygen in the air that needs also more fuel to have the right mixture...
so why you go leaner with the 42.5..and 330. ?? this numbers are for the inner diameters in the jets... no wonder that your bike will not start... :wink:
take a 50 pilot jet and a 360 main. needle in the middle and airscrew 1,5 turns open .. then try starting again... in my bike is actual a 52 pilot for the cold german weather.
now i´m excited what happens next... 8-)
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I was thinking about that black oil in the exhaust, and probably the reason why it's black is due to the carbon in the exhaust. So that explains that...
As to the jets....I had the bike running after the rebuild in the summer with stock jets, but it took several kick to always start it....and it would backfire before it started. Each time I would check the plug and it was wet, so I assumed it was running rich.
I bought leaner jets thinking it was fix the problem but never did. My plug always looked clean and tan in color why it did run...
Now I have the fuel in the exhaust so again I'm thinking a rich condition....
Today I'll try to get some of that excess fuel in the crank case out by kicking it over without the plug and exhaust. Last time I did this I was able to get running (on stock jets). Took a lot of kicks but she started....then the following day I had issues.
dinky,
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I was thinking about that black oil in the exhaust, and probably the reason why it's black is due to the carbon in the exhaust. So that explains that...
BINGO!!
and I don't buy the "too rich" gig either, especially since you already stated you had it running in the summer with a "clean tan plug".
I would go back to alward25's post, and start there...just because things are new, does not mean they're "good"...where did you get the float valve from?...cheap ones don't last!!
Re-check your float height while you're at it!
Does it have brass floats?...they can become corroded and get pin holes in them, creating your fuel to constantly flow.
if all this checks out...then you should start thinking about cleaning your electrical grounds on the frame and the plugs.
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I was thinking about that black oil in the exhaust, and probably the reason why it's black is due to the carbon in the exhaust. So that explains that...
BINGO!!
and I don't buy the "too rich" gig either, especially since you already stated you had it running in the summer with a "clean tan plug".
I would go back to alward25's post, and start there...just because things are new, does not mean they're "good"...where did you get the float valve from?...cheap ones don't last!!
Re-check your float height while you're at it!
Does it have brass floats?...they can become corroded and get pin holes in them, creating your fuel to constantly flow.
if all this checks out...then you should start thinking about cleaning your electrical grounds on the frame and the plugs.
Thanks for the suggestions...The needle & seat are literally new. Float height checked yesterday. A few weeks ago I submerged the floats in a jar of premix and they were fine. I shook them just to see if I could hear fluid, but nothing in there.
The other thing I want to replace is the intake boot which on the outside shows cracks, but on the inside looks sealed.
Boyesen has a one piece reed cage/intake I was looking at. And although I checked my reed cage/reeds they looked good without any visible gaps...the new Boyesen intake might have better sealing which might boost my compression level.
I was also entertaining the idea of buying a new Mikuni VM38....I've always had a feeling about my current carb....just something about it.
Oh, and 1 last thing....I going to get fresh gas and mix up some fuel just to see if that's the problem.
dinky,
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The needle & seat are literally new.
the other thing I want to replace is the intake boot which on the outside shows cracks, but on the inside looks sealed.
dinky,
if they're aftermarket, don't have high hopes!...been there, done that....that's why I bought a completely brand new carb...aftermarket replacement parts for carbs are garbage.
Sandblaster has a good thread on how to seal up old intakes.
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all of the intake boots are cracked, even new they look like trash. But it does not hurt.
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Well, I got fresh gas mixed 50:1....
Still no go. Funny thing is, after draining the carb, opening he petcock, choke on, and first or second kick I could hear a little backfire in the exhaust chamber...almost like a fizz.
I just think somehow fuel is going straight from the carb into the exhaust....snuffing out the spark.
Today I kicked it about 10-12 times, pulled the exhaust off and a table spoon or two dripped out of the pipe...granted some could have been left over from me dumping it yesterday but it seems like it's loading up.
I have a new air cleaner, reeds. When I have the carb apart I can see it's clean inside. I check all the jets, shine a light to see if anything is plugged. I set the float, make sure the needle & seat didn't leak etc....
I have an blue consistent spark, new coil, stator.
Only thing bugging me is the compression is 140psi after a complete rebuild. After 10 or so kicks...not sure how many kick I should do. The guy I brought it too honed the cylinder and it still had honing marks from 8 or so years ago. Maybe I should have bored it out...or re-plated....did 87 KX 250's have plated cylinders?????
When I get it started it runs normal....the idle does wonder up and down every now and then, nothing drastic...but it has power in 1st, kicks up the dirt.
It's a mystery..
dinky,
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When doing a compression test are you holding the throttle wide open and kicking it?
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"Now I have the fuel in the exhaust so again I'm thinking a rich condition.... "
this fuel in the exhaust is unburned fuel and comes from the many trys to start the bike with the to lean jetting!!!
you said it was running in summer but with also many kicks. so i know, that your pilot jet was in summer a little bit to lean too!!
now we have winter: colder temps= more oxygen in the air, so you need the richer jetting for right mixture and the bike runs.. what you did was leaner jets instead of richer jets... :roll:
make sure that the float valve could close and that the floats are moving freely up and down . now we closed the circle with your bike-problems...
dry your crankcase and exhaust, then try this jetting :
pilot 50 , main 360, needle in middle , airscrew 1,5 out ...
dont think to much about other things, do it... :wink: or let it, come to me to germany and i make your bike running in 30 minutes :-D
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Only thing bugging me is the compression is 140psi after a complete rebuild.
When I get it started it runs normal....the idle does wonder up and down every now and then, nothing drastic...but it has power in 1st, kicks up the dirt.
It's a mystery..
dinky,
140 is a touch weak for a fresh rebuild, if you're doing the test correctly.
if your idle is fluctuating...then a leak down test should be your next step...or you'll be just pissing into the wind messing with jetting if you have an air leak. :wink:
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sandblaster,
The compression test is with the throttle wide open....but the bike is on the ground with me kicking as opposed to the bike being on a stand.
motopunk,
I'll get the jets you recommended...50 pilot, 360 main....I have nothing to lose :)
And BTW I'd be happy to visit you....most of my family is in Poland just next door :)
Foxx4Beaver,
I tried a pressure test but I just couldn't get the intake boot side to seal. However, when I put in 6psi it dropped 1psi in a little over a minute due to me not being able to seal the intake properly.
dinky,
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Any time, just let me know ahead of time so I can make room on my bench :-D
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sandblaster,
The compression test is with the throttle wide open....but the bike is on the ground with me kicking as opposed to the bike being on a stand.
motopunk,
I'll get the jets you recommended...50 pilot, 360 main....I have nothing to lose :)
And BTW I'd be happy to visit you....most of my family is in Poland just next door :)
Foxx4Beaver,
I tried a pressure test but I just couldn't get the intake boot side to seal. However, when I put in 6psi it dropped 1psi in a little over a minute due to me not being able to seal the intake properly.
dinky,
poland is just an hour away from me ... next polish citys are stettin (sczezcin) and chojna... where is your family located?
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sandblaster,
The compression test is with the throttle wide open....but the bike is on the ground with me kicking as opposed to the bike being on a stand.
motopunk,
I'll get the jets you recommended...50 pilot, 360 main....I have nothing to lose :)
And BTW I'd be happy to visit you....most of my family is in Poland just next door :)
Foxx4Beaver,
I tried a pressure test but I just couldn't get the intake boot side to seal. However, when I put in 6psi it dropped 1psi in a little over a minute due to me not being able to seal the intake properly.
dinky,
poland is just an hour away from me ... next polish citys are stettin (sczezcin) and chojna... where is your family located?
I was born in the states...but my mother's side is from a small town near Krakow...little rock when translated to English...
I ordered those jets you suggested today..Tuesday next week will be the moment of truth :-D
dinky,
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sandblaster,
The compression test is with the throttle wide open....but the bike is on the ground with me kicking as opposed to the bike being on a stand.
motopunk,
I'll get the jets you recommended...50 pilot, 360 main....I have nothing to lose :)
And BTW I'd be happy to visit you....most of my family is in Poland just next door :)
Foxx4Beaver,
I tried a pressure test but I just couldn't get the intake boot side to seal. However, when I put in 6psi it dropped 1psi in a little over a minute due to me not being able to seal the intake properly.
dinky,
poland is just an hour away from me ... next polish citys are stettin (sczezcin) and chojna... where is your family located?
I was born in the states...but my mother's side is from a small town near Krakow...little rock when translated to English...
I ordered those jets you suggested today..Tuesday next week will be the moment of truth :-D
dinky,
german name is krakau... definitely more than 3 hours away from me.. :wink:
ok, let me know next week, how it works...
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OK...I'm hoping jetting is the issue...
dinky,
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Installed the jets, tried to start it, but no go...
Still the same thing....nothing...1 little backfire and me kicking it but not starting.
I think I'm done with this bike for a while......maybe next year.
dinky,
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I was also entertaining the idea of buying a new Mikuni VM38....I've always had a feeling about my current carb....just something about it.
I'd like to know more about this "feeling" you have about your carb...something doesn't sound right there :roll:
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I'm venting a little because I'm pissed it's not running and I might need to dump more money I don't really have..
Anyway, the engine has about an hour since I rebuilt everything.
When I get my head clear and think reasonable, I'll see if I can get the pressure test done again.
And that feeling about the carb is because it's the only thing I didn't replace.
dinky,
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I'll tell you a quick story...
last year at this time, I was about $6500 into my rebuild on my '95 500...I had replaced just about everything, because I wanted it to be as new as possible. The carb was the original one, and it was sacked out, played out, just straight up sloppy loose. I had replaced the seat 4 times in it, and replaced several OEM float valves, and it was never right...it was just too worn out.
Last December, once I got it fired up for the 1st heat cycle, it was pouring fuel out of the overflow tubes after I shut it off. The 2nd heat cycle, it was pouring out of the overflow tubes whilst it was running!!.
So at that point, I was so disgusted with playing with a junk carb, I said, "at this point what's another $300", and bought a complete brand new Keihin from Sudco.
Since then, I've never had any problems what so ever.
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I'm not saying go out and buy a new carb and all your problems will be solved, that's why I'm saying do a leak down test...it's free, and can eliminate a lot of potential headaches.
Do you, or a buddy have another carb you can try, even if it's just for a few minutes to see if it'll start and run better?...even if one of your buddies pulls their carb off their own bike for you to try.
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I was just going to say that I pulled the carb from my 250 just to test the 125 it started 2nd kick wasnt the same carby but it sealed up and told me that the problem was the carb. I no u put alot of time into the rebuild hope u get it sorted out
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OK so something magical just happened....maybe divine intervention...
I put the bike up on the stand (something I never do when I try to start it) climbed up on the bike, gas on, choke on, felt the kick starter and put the piston at TDC raised the kick starter....kicked it solid and she started right up :-o 1st kick (double :-o :-o)
She has NEVER started 1st kick....
Moved the bike off the stand and out the garage since the fumes were killing me.
Let her run about 10 minutes or so...blurping the throttle (neighbors must have loved me at 8pm).
Messed with the idle and air screw and got a smooth idle. Not sure if a dirt bike should have a lumpy or smooth idle.
Yeah, the idle went up and down a few times...but hey it started....
Not sure what to do now :?. Maybe I wasn't kicking it hard enough trying to start it?????
I usually find TDC on the kick starter and kick from there...the lever is 1/2 way down at that point.
Usually when I find TDC and bring the lever up, I can kick it but 1/2 down the lever stops on me like I don't have enough power in my leg to follow through...
I'm scratching my head and wondering if it was my wimpy kicking that prevented it from starting.
dinky,
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still, do a leak down test if the idle is fluctuating!...that could be an air leak, and it could fry your fresh motor!
my '83 CR125 was the same way 30 years ago...gas on, choke on, don't even touch the throttle, kick from TDC, and it would lite right off.
once it's fully broken in, then you can do some plug chops to get a better idea how the jetting is...providing it passes the leak down test.
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I would also suggest finding somewhere u can ride the bike pull through the gears, Putting around in the backyard wont do much i wouldnt think but hey Im new to this also ;)
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So I lowered the bike a little over an in.
This time without the stand, no choke, piston at TDC, kick starter up high, kicked it and started again on the first kick :?.
Forgot to mention I had a new spark plug when I got it started the 1st and 2nd time. It had the old one when I couldn't start it.
Idled for about 3-4 minutes...took a compression test after about 25 kicks and still came up 140 psi.
The dirt bike shop honed the cylinder and it looked pretty....now I could see marks up and down the cylinder when I look inside. Not scratches I can feel, but those marks are not even...just streaks.
After honing:
(http://i166.photobucket.com/albums/u84/kezard/20140517_210824_zps00e91a80.jpg)
This is before honing....but it looks like this now:
(http://i166.photobucket.com/albums/u84/kezard/20140424_205909_zps355cfe94.jpg)
(http://i166.photobucket.com/albums/u84/kezard/20140424_205919_zpsfbfa7786.jpg)
Should I have bored it out to make sure the cylinder was perfectly round throughout the whole barrel?
And I'll try that leak down too....
dinky,
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Hey Dinky.
I know you spent some dough on that piston but I would bore it to the next size up which would mean getting a new piston.
140 psi after several kicks isn't the greatest.
On the flip side, more displacement means more go power 8-)
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140 psi after several kicks isn't the greatest.
+1...that's a bit weak....or weaker than I'd want to see it if it were mine.
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Hey Dinky.
I know you spent some dough on that piston but I would bore it to the next size up which would mean getting a new piston.
140 psi after several kicks isn't the greatest.
On the flip side, more displacement means more go power 8-)
I was thinking the same thing when I was rebuilding it, but decided to get it honed based on what the guy at the shop said....
If I get it bored, does it have to be plated or anything?
This site, http://www.rpjperformance.com/ could bore, hone and chamfer the ports for $45 per hole.
Is this about right?
dinky,
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Since you have a sleeved cylinder you do not need to get it plated.
45 bucks is about what some of the local shops want.
What kind of piston are you going to buy?
Regardless of what you get you want to be sure that the company that is going to bore it has the specs from that piston manufacture.
Then, before you install everything you want to measure the ring end gap and the cylinder to piston clearance.
Make sure it's in spec BEFORE you put it together.
Also, check to see if you need to drill any oiling holes in the piston.
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Since you have a sleeved cylinder you do not need to get it plated.
45 bucks is about what some of the local shops want.
What kind of piston are you going to buy?
Regardless of what you get you want to be sure that the company that is going to bore it has the specs from that piston manufacture.
Then, before you install everything you want to measure the ring end gap and the cylinder to piston clearance.
Make sure it's in spec BEFORE you put it together.
Also, check to see if you need to drill any oiling holes in the piston.
The piston that was originally in the bike was a wiesco std bore. So I got the same for the rebuilt.
That shop I noted will take your "supplied" piston and measure it, then bore the hole to match. I would probably include the rings too for them to check the fit...I should be good after all this....
Might not happen till next year though...
Also, I never heard of drilling any oiling holes....at least the instruction I had with the wiesco piston didn't say I needed any.
dinky,
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I don't see that you have an exhaust bridge so you should be ok without the holes.
However, if your piston does not have any oil holes in the wrist pin area I would seriously consider adding some like this.
Note the holes on the left but none on the right:
(http://www.oem-cycle.com/forum/download/file.php?id=1330)
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I don't see that you have an exhaust bridge so you should be ok without the holes.
However, if your piston does not have any oil holes in the wrist pin area I would seriously consider adding some like this.
Note the holes on the left but none on the right:
(http://www.oem-cycle.com/forum/download/file.php?id=1330)
I'll check my original wiseco piston...I'm curious now.
Don't you have to chamfer the hole where the wrist pin is, to avoid any sharp edges?
Is it like a DIY thing? And how large of a hole?
dinky,
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Don't you have to chamfer the hole where the wrist pin is, to avoid any sharp edges?
Is it like a DIY thing? And how large of a hole?
dinky,
it's ALWAYS a good idea to thoroughly check any part that's going into your motor for burrs and abnormal edges...yes, it is a DIY thing.
1/8" would be suffice.
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OK so something magical just happened....maybe divine intervention...
I put the bike up on the stand (something I never do when I try to start it) climbed up on the bike, gas on, choke on, felt the kick starter and put the piston at TDC raised the kick starter....kicked it solid and she started right up :-o 1st kick (double :-o :-o)
She has NEVER started 1st kick....
Moved the bike off the stand and out the garage since the fumes were killing me.
Let her run about 10 minutes or so...blurping the throttle (neighbors must have loved me at 8pm).
Messed with the idle and air screw and got a smooth idle. Not sure if a dirt bike should have a lumpy or smooth idle.
Yeah, the idle went up and down a few times...but hey it started....
Not sure what to do now :?. Maybe I wasn't kicking it hard enough trying to start it?????
I usually find TDC on the kick starter and kick from there...the lever is 1/2 way down at that point.
Usually when I find TDC and bring the lever up, I can kick it but 1/2 down the lever stops on me like I don't have enough power in my leg to follow through...
I'm scratching my head and wondering if it was my wimpy kicking that prevented it from starting.
dinky,
the describe of your starting sounds a little bit like to much compression now after the rebuild... you can try a second base-gasket to see if it would be better...
but its nice to hear, that the bike was running now... ;O)
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I like to use 500 grit sand paper and just lightly clean up any sharp edges.
its not that the piston will scratch the cylinder wall but it can act like a wiper and wipe the oil off your cylinder.
the key it to LIGHTLY smooth the edges.
kinda like what Foxy was talking about.
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Sandblaster,
The original piston has those holes....and although I don't remember them on the new piston, it's the same make and model, so I would "assume" the holes are there too.
motopunk,
I wish my problem was too much compression. I've measured it with the engine clod and after running it, and both times it was a sad 140psi :-(
Thanks for your help!!! I probably wouldn't have tries those bigger jets. The true test will be if it starts again. But since I really don't have a place to ride, I don't want to keep idling the bike all the time.
dinky,
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Don't assume.... Wiseco has really cut back on their machine steps to save all they can on production.
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Since you have a sleeved cylinder you do not need to get it plated.
45 bucks is about what some of the local shops want.
What kind of piston are you going to buy?
Regardless of what you get you want to be sure that the company that is going to bore it has the specs from that piston manufacture.
Then, before you install everything you want to measure the ring end gap and the cylinder to piston clearance.
Make sure it's in spec BEFORE you put it together.
Also, check to see if you need to drill any oiling holes in the piston.
Just for ha-ha's I called a shop to see how much it would be to bore out the cylinder and he said ballpark about $700.
He said after boring you would need to:
Port the cylinder to match all the ports since it's a bigger bore now
Do something with the power valves, I guess port or match them
New piston, gasket, clean power vales
Is all this really necessary?
They did however say to get a quality pressure gauge as my new harbor freight might not be accurate...could an inexpensive gauge be 30psi off?
dinky,
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dinky put your bike on a trailer and take it to a place, where you can test it and ride it with the jetting , that i spoke off and maybe you need a little bit practice how to kickstart the 250 in the right way... :wink:
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dinky put your bike on a trailer and take it to a place, where you can test it and ride it with the jetting , that i spoke off and maybe you need a little bit practice how to kickstart the 250 in the right way... :wink:
Yep...I'm with you on that....That would be the best.
Just have to find "that place".
dinky,
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I wouldn't ride it at all until you're SURE it's not suckin air somewhere...or you will fry it.
remember, you said you weren't sure how your 1st attempt went because you couldn't get a good seal, but it lost pressure quickly...secondly, you said the intake boot looked iffy...and third, you've said twice that the idle fluctuates up and down.
that's 3 tell-tale signs of an air leak...unless you don't care if it blows...then by all means, go tear it up!
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I wouldn't ride it at all until you're SURE it's not suckin air somewhere...or you will fry it.
remember, you said you weren't sure how your 1st attempt went because you couldn't get a good seal, but it lost pressure quickly...secondly, you said the intake boot looked iffy...and third, you've said twice that the idle fluctuates up and down.
that's 3 tell-tale signs of an air leak...unless you don't care if it blows...then by all means, go tear it up!
I'm with you...the ride won't happen for a while. I was just agreeing with riding once I get these issues sorted. Plus it's cold, bikes still has parts that are not on....and I don't have a trailer or carrier for it yet.
I'd like to do a proper pressure test it also...no worries. I'm not in any rush.
dinky,
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I wouldn't ride it at all until you're SURE it's not suckin air somewhere...or you will fry it.
remember, you said you weren't sure how your 1st attempt went because you couldn't get a good seal, but it lost pressure quickly...secondly, you said the intake boot looked iffy...and third, you've said twice that the idle fluctuates up and down.
that's 3 tell-tale signs of an air leak...unless you don't care if it blows...then by all means, go tear it up!
I'm with you...the ride won't happen for a while. I was just agreeing with riding once I get these issues sorted. Plus it's cold, bikes still has parts that are not on....and I don't have a trailer or carrier for it yet.
I'd like to do a proper pressure test it also...no worries. I'm not in any rush.
dinky,
no mx-track near by you??
what you can do before the next ride is to change all gaskets and seals, if there are still old ones. dont forget the little seal on the exhaust valve rod (right side of cylinder) thats often the location of air leak ..replace the intake boot! so youre on the safer side..
you can do a very simple air leak test on the running engine... take brake-cleaner-spray to the outside of the running engine to all gaskets/seals where you mean, there could be an airleak.. if the engine immediately idles higher, you have found it...
i would need a video of the running bike, to see and hear how it runs and idles in cold and warm condition.
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Update...
The day started out with me cursing :x but ended on a surprisingly good note :-D.
I built a pressure tester:
(http://i166.photobucket.com/albums/u84/kezard/Pressuretestor_zps3148ff52.jpg)
The gauge if anyone is interested is a low pressure slime product you can get at pep boys for ATV tires. I unscrewed it and fitted it on the tee fitting. The only part I had to make was that plug on the right which consists of 2 pieces of 1/2in. aluminum screwed together with gasket sealer between to the two halves.
After pumping it up I traced an air leak I thought was coming from the exhaust port plug but was actually coming from the governor rod/rack. It would loose air pressure in a matter of seconds but could hold 3 psi pretty good.
After cursing some more, and researching I found out I had installed this part backwards.
(http://i166.photobucket.com/albums/u84/kezard/GovernorSeal_zps978a29f7.jpg)
After reinstalling and re-lubing, I added 6 psi. and after 12 minutes I only lost .5 psi.
I didn't think this would be possible with a motor that old, but hey, I replaced every seal and bearing I could find...
Also, that .5 psi. is because I have 2 small air leaks on each side of the reed cage. I had used gasket sealer on the intake boot, cage, but not on the gasket to cylinder surface, which is where the leak is coming from...That will most likely get fixed either with sealer, or a Boyesen RAD-12 intake.
I'm happy now... :-D
dinky,
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excellent!...I knew it had an air leak :wink:...which would've also contributed to the hard starting.
use a small skim layer of yamabond on the reed cage gasket to cylinder...problem solved. :-)
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excellent!
use a small skim layer of yamabond on the reed cage gasket to cylinder...problem solved. :-)
Yeah, that was my solution too...but under normal conditions, should you need to use sealer?
It seems like using sealer would be like "rigging" it to work.
And I've used yamabond exclusively on this build. Good stuff, as recommended here. Glad I went with that.
dinky,
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It seems like using sealer would be like "rigging" it to work.
not at all...there's a few guys that use yamabond on the reed cage gasket...it's one of the critical points, as you just found out :wink:
I even use yamabond as thread locker on certain nuts/bolts/screws....it's more forgiving and holds better than thread locker in some areas.
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Never thought of using it as a thread locker....good to know!
dinky,
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So I'm able to start my bike consistently now.
I installed a bigger main jet and pilot, and replaced my worn kick start lever.
But I "believe" the issues I had starting it was my lack of knowledge starting a 2 stroke.
I now prime it by 3-4 slow kicks, find TDC, retract the lever and kick it like hell.
In the past, when I found TDC, I couldn't kick past that next compression stroke. My foot always stopped and I wasn't able to follow through.
Now with the new lever, and confidence that the lever won't break, I'm able to kick all the way through.
And today I was able to start it in 4-5 kicks, and it's about 20 deg. outside, so I think I should be good this summer.
Thanks again for all your help,
dinky,
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right on Dinky...
yes, 3-4 slow kicks 1st is the key...some guys like to lean the bike over until fuel drools out the overflow tubes...I myself never understood why anyone would want to dump fuel on the ground every time they start a cold bike, when 3-4 slow kicks primes it the exact same way.
I don't even have to prime my 250...it doesn't matter if it's sat for 4 days, or 4 months...1 good kick, and it lights right off every time...it's a keeper!
My 500, 4 slow 1/2 kicks, then one good kick and it lights right off.
Not sure how much riding you'll be doing over the next couple months in 20 degrees :|...it's only 6 degrees where I'm at :?...but pay attention on how it runs, you may need to go a little richer, or a little leaner...the end of your silencer will let you know if it's rich, if it starts leaking black kucka and spraying your rear fender with black speckles....WOT plug chops will tell you what you need to know/do also.
Keep in mind also, you'll want to lean it out again in a few months once the temps start getting warm again.
Have fun and enjoy!! :mrgreen:
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But I "believe" the issues I had starting it was my lack of knowledge starting a 2 stroke.
I'm sure that played a role to some extent...but that air leak issue I suspected you had, played an even bigger role in the hard starting.
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I'm a bike leaner, but it depends on the fuel you use. With Cam 2/Sunoco 260GT 110 race gas, when I roll the bikes out every weekend the float bowl fuel has already evaporated. So on goes the petcock, a quick lean over, put it in gear and rock back & forth about two times to charge the cylinder. One or two good full kicks to get the 250, 300 or 500 fired after the drill (whether its 95 or 14 degrees out). When we used pump, usually could just roll 'em out, give a couple of good kicks & fire right-up.
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yup, every one has their own starting preference...I used to run cam2 for years...and I still prefer it, there was a gas station 20 minutes away where I could get it right at the pump, then they suddenly stopped selling it because they didn't sell enough of it....then it became a pain in the a$$ to get around here. Luckily I live literally 200 yards from my Kawie dealer, and they sell the 5gal buckets of vp-c12.
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Not sure how much riding you'll be doing over the next couple months in 20 degrees :|...it's only 6 degrees where I'm at :?...but pay attention on how it runs, you may need to go a little richer, or a little leaner...the end of your silencer will let you know if it's rich, if it starts leaking black kucka and spraying your rear fender with black speckles....WOT plug chops will tell you what you need to know/do also.
Keep in mind also, you'll want to lean it out again in a few months once the temps start getting warm again.
Have fun and enjoy!! :mrgreen:
Nope, no riding in this cold weather....just starting it every few weeks. I like to start my "key" equipment every now and then. Not really a big fan of not starting it for months, unless it's my 25 yr. old lawn mower, which starts first pull every time no matter what.
When I was in my teens I always rode things not matter what temp it was. Be it my moped on the ice lake, or the 73 Suzuki 350 2 stroke street bike my uncle gave me....but back then I had a place to ride and no one really cared what noise you made. Now it's different.
But I still have to rebuild my rear shock which drips every time I sit on it, front fork seals, grips, etc.
dinky,
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Nope, no riding in this cold weather....just starting it every few weeks.
Yup, that's how I feel....
I have a snowmobile to ride for the winter with heated grips and a bit more protection from the wind.
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hey dinky, nice to read that you found the major problem...
i use hylomar for sealing my readcage . it has an very important fact: it is gasoline-resistent :wink: hylomar was invented by the rolls royce flight-motor builders and it it is awesome . i also use it as thread locker.
now to the actual german winter: up and down between -5 and + 10 degree celsius (not sure how much it is in fahrenheit), storm, and it rains the s**t from the sky . even there is one dry day, you dont want to ride in this mud-soup and water mix everywhere around... :|
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We are very fortunate to have four Cam2/260GT dealers within a 20 minute drive from our house (but we're also not far from a track & the local off-road community is strong around here). We ride all winter, snow or no snow. We have friction spikes for the fluff & ice and no sense for the mud & cold. I don't blame anybody for not cold riding (I have to drag my husband out sometimes off the couch :-D), but tight woods in the winter will keep you warm.
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(I have to drag my husband out sometimes off the couch :-D)
haha...I can admit, in my older age I've become a little bit more of a "fair weather rider", and have to talk myself into suitin-up at times too.
but if it's the day after a light to medium rain...then I'm out riding for that entire day! :-)