KX Riders
Maintenance & Technical => KX500 Original => Topic started by: NastyNick on January 23, 2004, 06:56:14 AM
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Hey all, I have a bunch of newbie mechanical questions that I hope you can answer for me.
background:
I own, among others, a 93' KX5 what has worked really well for my type of riding, but the previous owners didn't do much to it as far as maint goes. So, I am in the process of rebuilding it. I CAN make it faster and stronger. hopefully it won't take 6 millions dollars to do it. ;)
Super newbie question 1: Whats the hole (drilled in the side) for on my new Tusk drain plug?
newbie question 2: Is it easier to do a top-end rebuild (see question 3) while the motor is in the frame? I have to pull it out anyway (frame welding job), but I read in my Clymers that it's sometimes easier to just leave it in the frame. Whats your experience?
newbie question 3: I am going to attempt my first top-end rebuilt myself. I am pretty good with a wrench, but have never cracked to top off a motor. Anybody have any suggestions or should I just take it in to the shop and let somebody else do it. Keep in mind that I have blown my "new bike" (kx250f) and my "upgrade" budgets for this year. Any more and my wife is gonna get reeaally mad. :)
I have already purchased a new Wiseco kit (pistion, wristpin, rings, circlips, etc), an engine gasket kit, and oil-seal kit and I think I have all the tools I will need.
newbie question 4: The previous owner of this k5 used belRay H1R at a 50-1 ration (one small bottle of oil to 5 gallons is what he told me). I used that same ratio all last year and it didn't seem to hurt anything, but with the new pistion and such, I am wondering if I should change things around. Keep in mind I don't ride the beast to it's full potential (yet).
newbie question 5: jetting? I order a new reed cage and reeds for it and am thinking I should change back to the stock jets. The previous owners had some goofy jets in it, but the motor ran fine. Strong through the whole powerband and didn't blubber or loadup. My qustion: What jets sizes should I use? I think the stock ones are a #60 pilot and a #168 main. I live and ride anywhere from 3500 feet to 5k in Montana. My problem is that I hate dinking with the jets after I have everything back together. I suppose the stock ones are a good place to start though. Does anybody think I should change them at all with the new reeds?
Any and all help would be appricated.
Thanks!
NN
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The hole in the plug is so you can saftey wire it to the frame so theres no chance of it falling out,be carefull tightening the plug,it can strip easily-just snug with the safety wire.You can do the top end ethier way,if you make a stand from 2x4's it's just as easy on your work bench if not easier.If you feel you can do it,buy a manuel,take pictures as you take it apart.If your worried and have your doubts have some one who knows how help or take it to a shop and pay them.I run 40:1 Maxima Super-M and like it,you can find some one to bad mouth just about any thing-so if your happy with Bel-Ray,run it,but I do like Maxima prouducts.Jetting is something you need to learn as your jetting can change with the weather,altitude,humidity,and tempature.I cant give you the jet #'s you need,but startring with stock and experimenting is where to start and how to learn how it affects your bike.Hope this helps some.
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Hey all, I have a bunch of newbie mechanical questions that I hope you can answer for me.
background:
I own, among others, a 93' KX5 what has worked really well for my type of riding, but the previous owners didn't do much to it as far as maint goes. So, I am in the process of rebuilding it. I CAN make it faster and stronger. hopefully it won't take 6 millions dollars to do it. ;)
Super newbie question 1: Whats the hole (drilled in the side) for on my new Tusk drain plug?
newbie question 2: Is it easier to do a top-end rebuild (see question 3) while the motor is in the frame? I have to pull it out anyway (frame welding job), but I read in my Clymers that it's sometimes easier to just leave it in the frame. Whats your experience?
newbie question 3: I am going to attempt my first top-end rebuilt myself. I am pretty good with a wrench, but have never cracked to top off a motor. Anybody have any suggestions or should I just take it in to the shop and let somebody else do it. Keep in mind that I have blown my "new bike" (kx250f) and my "upgrade" budgets for this year. Any more and my wife is gonna get reeaally mad. :)
I have already purchased a new Wiseco kit (pistion, wristpin, rings, circlips, etc), an engine gasket kit, and oil-seal kit and I think I have all the tools I will need.
newbie question 4: The previous owner of this k5 used belRay H1R at a 50-1 ration (one small bottle of oil to 5 gallons is what he told me). I used that same ratio all last year and it didn't seem to hurt anything, but with the new pistion and such, I am wondering if I should change things around. Keep in mind I don't ride the beast to it's full potential (yet).
newbie question 5: jetting? I order a new reed cage and reeds for it and am thinking I should change back to the stock jets. The previous owners had some goofy jets in it, but the motor ran fine. Strong through the whole powerband and didn't blubber or loadup. My qustion: What jets sizes should I use? I think the stock ones are a #60 pilot and a #168 main. I live and ride anywhere from 3500 feet to 5k in Montana. My problem is that I hate dinking with the jets after I have everything back together. I suppose the stock ones are a good place to start though. Does anybody think I should change them at all with the new reeds?
Any and all help would be appricated.
Thanks!
NN
Hey, welcome. I've got a 94 that I'm currently rebuilding. It's been fun and spendy. The guy who owned this didn't do any maintenance as far as I can tell. With some of the wear in the bottom end I'd be surprise if the oil was ever changed.
1.Hole is used to attach a piece of wire from the hole to the frame so it doesn't fall out.
2. I haven't done the topend in the frame. I pulled the motor. Not hard to do. Probably the hardest part is the swingarm bolt. Make sure everythings supported BEFORE you pull that bolt. Basic tools should do it. Oh, you'll need a in.lb. wrench and a ft.lb. wrench. Make syre you look at the plating in the cylinder. It may be wore out.
3. Top end is easy. Bottom gets tougher but it's not bad either. Don't waste you money on a shop charge. If you get stuck post it here and it will be answered ten fold. This place is like your own personal mechanic.
4. 50:1 is too "something". I use 32:1 and I know some guys here use 40:1. I'll defer to someone that has more knowledge on this. For the new top end I would stay at what the factory wants but that's just my opinion. Again, I'm out of my element with this question.
5. For jetting start with the FAQ's. This chart gives an idea to start with. My KX has a 162 and a 62. I ride at about a 1000ft. Mine is not jetted correctly and ran like crap. I'll defer this one also. Do you need new reeds?
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saftey wire
doh! I knew it had something to do with that. The Tusk plug appears to made out of aluminum and not a big fat steel bold like the original.
With some of the wear in the bottom end I'd be surprise if the oil was ever changed.
The DFO (dreaded former owner) didn't have that problem. He had a leaky o-ring and seal on the counter-shaft side. He went through 6 quarts of gear lube a summer, just riding it once a week for a couple hours. It leaked all over his floor. Didn't make monetary sense tho, at 7 bucks a pop for the oil, a 6.95 seal and pennies for the o-ring. Then again, he never had to change the fluid. :)
I use 32:1 and I know some guys here use 40:1
I tried experimenting last summer and U found it splooged way bad with any thing other than 50:1. maybe a carb issue?
Do you need new reeds?
Yeah, probably. i pulled them out and they were cracked and appeared to be "burnt". Burnt isn't the right word...more like discolored.
Thanks for the help guys...I'll think I'll pull the motor out tonight and get started on it.
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Well, since you have answers on most of your questions, I'll not chime in on any of those. However, here are a few additional items.
1. Bel-Ray at 50:1 - H1R is a synthetic oil, and can be run at 50:1 without any damage to the motor. Other oils with different molecular structures require different ratios. Stay with Bel-Ray and you will be fine.
2. Top end job will take less than an hour if you leave the motor in the frame (I've probably done a hundred this way). However, if you have to take the motor out anyway to accomplish frame repairs, change the top end with the motor on the bench. If this is the first time for you, you will be able to watch the process better on the bench.
3. A top end job DOES NOT require taking the head off the jug. If the head is not leaking, and mods are not going to be done, leave the head on the jug. This will require a little more wiggle to clear the frame when you pull the jug while still in the frame, but just rotate the piston all the way to the bottom of the stroke and you will have enough clearance. When you put the jug back on the motor, have someone else sitting on a stool on the other side of the bike to help guide the jug down as you sqeeze the rings together. The piston has a ring locater pin in each ring groove, so extra help with jug installation helps avoid damage to the rings.
4. While the jug is off, clean the power valves. I have a couple of posts on the process on this site, but if you can't find them, just say the word.
5. The counter shaft oil leak can probably be fixed with a thicker o-ring. Paul can post the part number from Home Depot. However, even if the seal is the culprit, it can be changed without pulling the motor.
6. While the motor is out, grease all the suspension. You will probably need a lower shock bearing (I go through a couple a year), but just change the bearing unless other parts are damaged. I have a post on how to change the bearing without any special tools and without pulling the suspension part.
7. While your changing pistons, stuff some rags into the crank chamber. This is easier than trying to fish for the piston pin clip.
This should get you started. Post up with any problems.
Enjoy.
Rick
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Glad to see I'm not the only one that does the top end in the frame without taking the head off.
Just make sure when you refill with coolant that you bleed the air out of the head. Its that bolt on top of the head, just loosen it til air bleeds out then a bead of coolant will form at the base. You don't have to remove it all the way. Dan H
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thats for the info guys! I really appricate it.
The counter shaft oil leak can probably be fixed with a thicker o-ring. Paul can post the part number from Home Depot. However, even if the seal is the culprit, it can be changed without pulling the motor.
I got a new seal and o-ring from the kawasaki dealer this past summer. No problems after that, but I did see the other posts about the home depot oring. Since I am going to replace the counter-shaft sprocket, I'll put in the home-depot o-ring when I get to that point.
While the motor is out, grease all the suspension. You will probably need a lower shock bearing (I go through a couple a year), but just change the bearing unless other parts are damaged. I have a post on how to change the bearing without any special tools and without pulling the suspension part.
hehe...I took the swingarm off (shock and all the linkage too) and I need bearings everywhere! They are all rusted out. I'll order the bearings tomorrow from Rocky.
d**n Tusk Magnetic oil plug doesn't fit! grrr. Same with the MSR swingarm rub-plate. I ordered them from Rocky and even on the package it says 89-04 KX-500, but they don't fit. Ordered the OEM from the Kawi dealer so I can get the right one, and i'll just use the original oil plug again. Doesn't leak anyway.
What kind of break-in period is there after a rebuild? Probably nothing on a 2 stroke, but just checking.
I convinced my wife to let me bring the motor in the house to work on it. It's currently 5 below zero (fahrenheit) and my garage isn't heated. Dang tools are coooooold.
thanks again!
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thats for the info guys! I really appricate it.
The counter shaft oil leak can probably be fixed with a thicker o-ring. Paul can post the part number from Home Depot. However, even if the seal is the culprit, it can be changed without pulling the motor.
I got a new seal and o-ring from the kawasaki dealer this past summer. No problems after that, but I did see the other posts about the home depot oring. Since I am going to replace the counter-shaft sprocket, I'll put in the home-depot o-ring when I get to that point.
While the motor is out, grease all the suspension. You will probably need a lower shock bearing (I go through a couple a year), but just change the bearing unless other parts are damaged. I have a post on how to change the bearing without any special tools and without pulling the suspension part.
hehe...I took the swingarm off (shock and all the linkage too) and I need bearings everywhere! They are all rusted out. I'll order the bearings tomorrow from Rocky.
d**n Tusk Magnetic oil plug doesn't fit! grrr. Same with the MSR swingarm rub-plate. I ordered them from Rocky and even on the package it says 89-04 KX-500, but they don't fit. Ordered the OEM from the Kawi dealer so I can get the right one, and i'll just use the original oil plug again. Doesn't leak anyway.
What kind of break-in period is there after a rebuild? Probably nothing on a 2 stroke, but just checking.
thanks again!
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Look at pg 19 in your owners manuel for how to break it in,if you dont have one I'll post it.Rockey Mtn's good at customer service,tell them the plug doesnt fit and you want to exchange it for the Moose plug.
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Mike,
I don't have an owners manual. Could you post some info on the break in period? Thanks!
Also, what does my Cylmers mean when the say to use "Assembly Oil" in certain spots on the top-end rebuild. Specificly is says to use a small about on the rings. Didn't think you had to use any oil on a 2-stroke. What the heck is Assembly oil? just a 30 weight motor oil? 2-stroke oil?
-NN
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Some go dry. I use Pre-mix oil.... :wink:
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I dont believe in the dry start,piston has to go through a few cycles to pull fuel/oil into the cylinder,so thats running with out lube-No Thanks.I coat a thin film of 2-Stroke oil on my piston/rings and cylinder,I dont use any grease because I want lubrication but I want the rings to break in also(Moly grease is great,but not on rings).Heres what the manuel has for break in 1.start engine,let it run at idle untill its throughly warmed up2.stop and let the engine cool completely3.start and ride for 10 minutes at moderate speed-NEVER HARD ACCELERATION 4.stop and let it cool competely.Be sure to make a general inspection 5.start and ride 20 minutes at moderate speed-NEVER HARD ACCELERATION 6.stop,let it cool completely.(I dont do the following,but this is in the manuel)inspect piston for scoring,if any sand with#400 to#600.Decarbon exaust ports and upper part of cylinder using #400 to #600.Remove carbon in head.Reassemble9.start and ride for 30 minutes at moderate speed-NEVER HARD ACCELERATION 10.Stop,let engine cool compleleley,check and adjust as needed 11.after break in bike is ready for regular operation,install new spark piug and change trans oil.Thats what the book has for break in,but this is for a new unridden bike,so you dont need to change the trans oil if it was fresh when you did the top end,and I dont tear the top end down in the middle of break in time,thats for a new bike that may have some cylinder coating flaws.I baby my bike a little longer than this,Im never in a hurry after doing a rebuild.
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pre-mix it is. Thanks for the info guys.
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You might consider drilling a safety wire hole in your bleed screw and safety wiring it.
I can tell you a REAL BAD story about Shane Espisto's bike at Vegas to Reno in '98...
Team Green welds the hole shut. I use the screw and keep a real good eye on it. I've never heard of the thing comin' out...except for that one time. Braasch thinks some-one, who was ex-Kawi, loosened it in impound.
Manny
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How do they bleed the air with it welded up?Good idea to safety wire it!
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They just fill it and bleed it out via the cap. If there's a real problem, I've seen them loosen a hose.
Manny
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I have never taken the bleed screw out. I glue in place with Loctite and leave it alone. Never had any problem with any bike after a rebuild. Bleed through the cap and leave the screw in place.
Rick
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Finally started on the top. What a mess! Whats the best/easiest way to clean the cylinder/exhaust ports?
Also, how much power will I gain by having a working power-valve? The powervalve on it is frozen. I am having a hell of a time getting the valves out of the powers. Looks like it's frozen down by the exhaust port. As a matter of fact the linkage under the governer cover was disconnected or had fallen a part!!
Cylinder/head and piston look good tho. I did get a wiseco piston/rings/bearing/clips/pin kit so I am going to use those instead of the old ones.
another question: do I need to use any gasket goop with my new gaskets? Looks like the old ones had some on it, but my books says nothing about it.
Heck, I might just take this all down to the dealer and have them do it.
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oven cleaner works good but you must wash it off when done because it will react with the aluminum. You need the power valve, it will provide the power mid range and up.
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d**n Nick, you REALLY REALLY want that fixed. If necessary a new jug is only about $300 or so and all the associated stuff would run you another $150 or so.
Take your time and try the oven cleaner. I've used WD-40 to free up frozen power valves and that doesn't affect the aluminum.
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Oven cleaner worked! I soaked with some mild (said it on the can ;) ) it for about 15 to 20 minutes, washed it with warm soapy water That loosened it up a bit, so I repeated the process. twice more. Finally got the valves up far enough to get the governer rod out. Had to repeat the process a couple more times to get the valves all the way out. Then the middle one came out too. It's one big chunk of carbon, but it starting to clean up a bit. I think it will be ok.
Paul: Where can you get a new cylinder for $300 at?? My dealer wants close to $600 for one then probably another 400 for all the other stuff! I think they charge full-boat retails on OEM parts.
Question on pistons: I picked up a new wiseco kit on eBay. Looks good, except there is a small (1/16" x 1/8") bur (for lack of a better word) near the rear of the piston. Will it be OK? It was packed real good, so I am not sure how that happened. If you don't think it's OK, my original piston looks good too (no breaks/crack/etc) except there is some really small pitting on the top.
Just think, I thought the beast was powerfully before! After all this, and a working KIPS, it should rip my arms out of the sockets when I give it the onion. :)
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:oops: I feel like an idiot asking this, but what are you guys talking about the oil bleeder hole and a drilled hole in the frame? Are you talking about the oil drain bolt at the bottom of the motor? or the little bolt in the side to check the oil height? I'm quite confused..
Anyway, I too am in another rebuild and I also have a serious leaky counter sproket leak. I guess it's time for another seal. :x
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Your not an idot,only someone who thinks they know everything and wont ask is an idiot.The bleeder is the small bolt in the head to bleed the air out as you add coolant,its nothing to do with oil and the hole was drilled in the bolt to safety wire it from vibrating out.
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Anyway, I too am in another rebuild and I also have a serious leaky counter sproket leak. I guess it's time for another seal. :x
Quit feeding that thing seals and read this thread:
http://www.pitbull-racing.com/index.php?name=PNphpBB2&file=viewtopic&t=434&start=0
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Well, I just did some research for a cylinder, here is what I found. None for $300. I did however find one for $399 at midwestaction cycle.
As for any one else, what do you all think about the wiseco piston kits. Some say yes some no. But all of the people I talk to own small bore 2 strokes.
Jody
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Ehhh, close enough. I remembered they were in three range :lol:
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A 500 can run quite well with lots of pistion issues. Two years ago, my oldest seized a piston in a brand spankin new KX500 on practice day at a National in California. Upon checking, it had a score all the way up one side about 1/16 deep and 1/8 wide. John had an extra cylinder in the Kawasaki semi, so we swapped off to a new cylinder. I later used the old cyliner with the score, and was shocked to find that there was almost no noticable power loss. For the average rider, they would never notice anything. In fact, the bike is still running the same "damaged" cylinder two years later. I also ran my 1999 KX500 cylinder too long, and found the plating on the exhaust side worn badly. Here again, little noticable power loss.
With all that said, as long as the slight damage on the piston does not effect the ring's ability to compress smoothly, I would use the new piston. If we were talking about a KX125, I would have a completely different oppinion.
Good luck
Rick
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Seals:
On my KX I could not get the counter shaft seal to stop leaking even after replacing the oring I then replaced the outer seal, still no go. I finally got the thing stopping by replacing the sleeve that pushes against the oring and sprocket.
Cylinder:
399 is as cheap as I've seen them. Treasure coast honda usually is the cheapest but they come in at 420.
In response to Ricks note. My KX probably has run 6-8 years without any maintanence! Except the lack of performance is very noticeable on mine. I question whether the previous owner ever changed the oil. Piston has a lean scoring and the cylinder has lost much of the plating especially on the exhaust valve side.
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Thanks for the info Rick. A mechmonkey friend of mine also said to use the new one. I showed it to him and he said not a problem. My cylinder is showing some wear, but not too bad. All nice an clean now. I think I will keep as is and save the bucks.
Now, if I could just get my main exhaust valve, left/right valves clean of all the carbon. They have been been taking turns soaking in solvent and oven-cleaner for the last few days. I even took a few turns with a dremel on it last night to break it up a bit. Making some progress, but it's slow.
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Sounds like quite a project. Too bad you dont have a spare K5 to ride in the mean time...
I just did the top end on my 2002. Looks like I had a partial seizure, and I didnt even notice...!! I emery-clothed the cylinder and buttoned it up and it's good to go for this weekend. Huge compression increase....I got a feeling the power wont feel a whole lot different, cuz like Rick said, big-block 2-strokes can handle a lot.
Good luck with your Jug...!!
Sharc
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Last question for a bit. waiting for parts.
Q: Do I need to use any kind of RTV on the gaskets when putting this back together? This includes the ign cover, cylinder, head, etc.
I talked with my dealer today and they said basicly the same thing that Rick posted above. It should run fine with normal wear on the cylinder and stuff. Just Scotch Brite (which Scotch Brite pad???) it up before installing it. He told me that LA Sleeve will re-sleeve the cylinder for about 150+labor. He said labor is usually another 150 or so. He also told me that he new of a company that will electo-plate and polish an old cylinder for about 150 total. What would you do?
I really appricate the info and help that I have found here. Thanks again!
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Send it to US Chrome for plating.
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or you could send it to lukes racing and he'll have it plated and shipping is free.does excellent work with good prices.lukes racing.com
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A lot of the race teams use Rick Peterson Motorsports:
http://www.rpmsbigbore.com/repair.htm
I have used Rick several times (even with big bore kits) with great results. He has also received a lot of favorable press in the dirt bike mags. Check out his web site for more info.
Rick
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Of course, there's eric-Gore.com. Several in this forum have used him with great success. I plan to get his 520 kit. I know at some point someone posted that they rec'd some lousy service but I don't know what happened to that issue.