KX Riders
Maintenance & Technical => KX250 / KX125 => Topic started by: dinkyguitar on September 09, 2014, 09:33:16 AM
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Hi All,
I have a problem starting my bike. (87 KX250)
When cold, I turn the gas on, pull the choke, kick it 3-4 times and it starts.
Today it ran for about 5 minutes and I stalled it trying to ride.
Kicked her over, but it wouldn't start. Pulled the choke for a few kicks and nothing.
Pulled the plug out and it's wet.
Yesterday I did the same thing and started it by giving it full throttle.
It has a new air cleaner, and when I took the carb apart it had stock jets and I blew out all the holes I could see.
The only thing I did not check was the float level. Could this be the issue?
My other thought was the timing which I set as per manual...I have 3 marks on the stator and I lined it up with the middle mark.
Other than that, I could feel the bike has compression, and I replaced all the seals.
Any thoughts?
dinky,
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you never said if the plug you took out had spark, you only said it was wet...check for spark, if it does, put a new plug in anyways for the mere peanuts they cost.
could've possibly busted a reed too...but start with the easiest things 1st...the plug.
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you never said if the plug you took out had spark, you only said it was wet...check for spark, if it does, put a new plug in anyways for the mere peanuts they cost.
could've possibly busted a reed too...but start with the easiest things 1st...the plug.
The plug is new and it has always started on the initial start. It's the second start right after it stalls or shuts off that's hard.
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Next time it floods, hold the throttle wide open and kick it a few times and see if it will start up.
Be prepared to shut the throttle down if it starts :-D
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wonder if your choke mechanism is hanging up a little.
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Next time it floods, hold the throttle wide open and kick it a few times and see if it will start up.
Be prepared to shut the throttle down if it starts :-D
That's how I got it to start that first time....
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wonder if your choke mechanism is hanging up a little.
I can feel and here it click when I give it choke....and it does go down from what I can see externally.
I also unscrewed that part and cleaned it.
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I had the same issues with my 87
the stock jetting is 350 main jet which was far to rich for me I couldnt keep plugs alive and even the 45 pilot was to rich too.
My 87 is now running a 320 main with #42.5 Pilot im ridding from 0-500 ft and weather is anywhere between 10-30 C If that helps I played around with the jetting and found it strange that the stock jetting was so far out might have just been my bike too.
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I had the same issues with my 87
the stock jetting is 350 main jet which was far to rich for me I couldnt keep plugs alive and even the 45 pilot was to rich too.
My 87 is now running a 320 main with #42.5 Pilot im ridding from 0-500 ft and weather is anywhere between 10-30 C If that helps I played around with the jetting and found it strange that the stock jetting was so far out might have just been my bike too.
Something to think about...
I took the carb off and found the float height to be 31mm instead of 27mm, which is what the manual recommends.
I couldn't test it since it was late....with no packing in the silencer it's kind of loud and my neighbors....or shall I say "neighborhood" would probably not like it :-D.
I'll try tomorrow.
dinky,
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I had the same issues with my 87
the stock jetting is 350 main jet which was far to rich for me I couldnt keep plugs alive and even the 45 pilot was to rich too.
My 87 is now running a 320 main with #42.5 Pilot im ridding from 0-500 ft and weather is anywhere between 10-30 C If that helps I played around with the jetting and found it strange that the stock jetting was so far out might have just been my bike too.
Where is a good place to get the mains and pilot?
dinky,
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I had the same issues with my 87
the stock jetting is 350 main jet which was far to rich for me I couldnt keep plugs alive and even the 45 pilot was to rich too.
My 87 is now running a 320 main with #42.5 Pilot im ridding from 0-500 ft and weather is anywhere between 10-30 C If that helps I played around with the jetting and found it strange that the stock jetting was so far out might have just been my bike too.
Where is a good place to get the mains and pilot?
dinky,
I use these guys periodically....they're pretty quick at getting things shipped out if you ask nicely...
http://www.pjmotorsports.com/keihin-jets.html#pilot/slow%20jets
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Are these jets interchangeable with Mikuni carbs?
dinky,
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explore the site....you'll find the Mikuni jets in there...
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here...
http://www.pjmotorsports.com/mikuni-jets.html
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I used these guys but I will check the other sire too http://www.ebay.com.au/itm/331289117204?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
scroll down to the VM38 (If u r using the correct carb) VM38SS
11.5mm in length with a 6mm Hex Head main jet
13.5mm in length with a 4.8mm Head (outside of threads)
(Description Note - 8 Bleed holes around the body) Slow jet
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here is the Mikuni jets from the site Fox posted
http://www.pjmotorsports.com/mikuni-jets.html
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Hey thanks guys....
Well, after setting the float height of 27mm (as per manual) I wasn't able to start the bike. I read in the manual this could cause a rich condition that would prevent the bike from starting....
After turning the fuel on and pulling the choke, I lightly kicked it 3 times and tried to start it on the 4th kick. It sounded like it back fires through the exhaust...not like a fire cracker, but more of a sound like pulling the trigger of an air gun.
I then, advanced the timing a small amount, and retarded it a small amount but nothing.
I checked the plug and it's wet. This is after 5 heat cycles and 2 very brief rides in 1st gear.
Could this plug be fouled? I do have another one...
(http://i166.photobucket.com/albums/u84/kezard/sparkplug_zpse9eb5d9f.jpg)
And the exhaust (no baffle material)...which could need to be blown out being it's a rebuilt engine.
(http://i166.photobucket.com/albums/u84/kezard/exhaust_zps377879cc.jpg)
dinky,
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Just took the reeds out....they have fuel on them also....
Question....should the reeds be easy to open if you push on them with your fingers from the inside of the cage?
dinky,
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So I adjusted the float to where it was originally and added a little more. Now there will be less fuel in the float bowl.
She started on the third kick and ran and idled good.
Shut the bike off, and was able to start it on the 3rd kick.
Shut it off and was not able to start it.
I changed the CDI to my spare but no go.
Plug was wet again and it backfired while I tried to start it.
I'm ordering a new set of boyesen reeds to rule that out.
dinky,
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another free thing to try is, take a piece of sandpaper/scotch brite, and clean all the contact points on the frame...and make sure all the connections are clean and not coated in green corrosion, and use a little dielectric grease on the connections.