kso i have had this 99 xr250r since about 350 miles old.... 2nd owner. i do the regular oil changes/air filter tires chain sprockets an now it has progressively gotten harder and harder to start. i have over the 3000-4000 miles on it never adjuster the cam/timing chain and dont know how. could this be the reason it quit?? it smokes minimally... and for an idea of how i ride it i have only went through two front and three rear tires(including originals) about a year ago i had a similar problem that ended up being the kill switch.... but after fixing that it has began to decline as far as starting ability again. i checked the kill switch again, adjusted valve clearance, cleaned the carb thoroughly, checked all the other wiring including coil and spark plug resistor, made sure the gas was good, changed both fuel filters(one in tank and the other inline) and replaced the spark plug..... still nothing. VERY hard to bump start and recently that does not even work. when it does run/ran it topped out about 78mph (i put a bicycle multi function speedometer on it lol) and pulled 0-60 about 6 seconds or so. lots of power but wont idle cold and barely will hot. any ideas? im really hoping i just need to tighten up the cam chain(which if i ride without my helmet i can hear..normal/bad?) cause i think im about 2500-3500 miles overdue...but how it this done? oh, lastly..... last time i took it out to check how it was burning fuel/air mix...i was pegged about 78-79mph and it started breakin up...so i slowed down a little and it kept doin this till i was only goin like 55-60. i started it a few days later, and no problem, although i did not wind out sixth all the way i did fourth on the dirt road. :(
cam/timing chain slack?
- Thread starter 99xr250r
- Start date
Hey!!!,
Below the carburetor, just behind the cylinder, on top of the case, there should be a rubber cap covering the cam chain adjuster. Remove the cap, remove the bolt on the top of the adjuster (10mm wrench), loosen the adjuster lock (14mm wrench), take something small enough to fit in the hole that you took the top bolt out of. You'll feel the adjuster pin, push it in and let it come back out on its own. Tighten the adjuster lock, and re-install the top bolt and rubber cap. The cam tenssioner is spring loaded and semi-self adjusting. If the top end is really noisy, you may want to take it apart and check it out. The cam chains do wear and over time will put your valve timing slightly out. Check the compression, your valves and piston rings may be worn bad enough to make the bike hard to start. It's probably time to re-build it.
Below the carburetor, just behind the cylinder, on top of the case, there should be a rubber cap covering the cam chain adjuster. Remove the cap, remove the bolt on the top of the adjuster (10mm wrench), loosen the adjuster lock (14mm wrench), take something small enough to fit in the hole that you took the top bolt out of. You'll feel the adjuster pin, push it in and let it come back out on its own. Tighten the adjuster lock, and re-install the top bolt and rubber cap. The cam tenssioner is spring loaded and semi-self adjusting. If the top end is really noisy, you may want to take it apart and check it out. The cam chains do wear and over time will put your valve timing slightly out. Check the compression, your valves and piston rings may be worn bad enough to make the bike hard to start. It's probably time to re-build it.
- Thread starter
- #4
sharky243, all i saw as far as rubber goes were some vent hoses for the crank case and one on top of the head that may be a vent/oil line.... i think im gonna go check out mrcycles cause they have the microfiche setup i could look through, what is the typical wear life of a cam chain? are you sure that is the location of a 1999 xr250r? i wonder if it has an automatic adjuster because i never had to mess with it before over the last 3500 miles. it never sounded real loud(cam chain)... then again the guy i bought it off removed the baffles so i cant hear too much engine noise.... i made a small baffle insert after i had the cops called on me a few times lol :nener: :laugh:
Ol'89r
LIFETIME SPONSOR
- Jan 27, 2000
- 6,961
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99xr250r said:
If you have not adjusted your valves on a regular basis, you probably have burnt valves and seats.
I believe your bike has a automatic cam chain adjuster. I would suggest buying a service manual for your bike. It will tell you how to check and adjust everything.
With that many miles on the bike, you probably need a top end rebuild. You may have worn rings or burnt valves or both. While you're in there, you can check the cam chain for excessive wear and also check the cam chain slider and adjuster for wear or broken parts.
Hey !!
OOPS !! you're right, that model does have a different cam chain tenssioner. It appears to be an automatic adjuster built into the rear cam chain guide on your bike. I was thinking of the older models. Oh well, I'm only human !! lol !!. I have replaced cam chains before to cure a noise. If there is a bad link in the chain, it will "tick" loudly as it goes around the sprockets. It actually sounds a bit like loose valve clearances. Check this site out, you can use it to look up your parts for your bike. (www.nielsens.com)
OOPS !! you're right, that model does have a different cam chain tenssioner. It appears to be an automatic adjuster built into the rear cam chain guide on your bike. I was thinking of the older models. Oh well, I'm only human !! lol !!. I have replaced cam chains before to cure a noise. If there is a bad link in the chain, it will "tick" loudly as it goes around the sprockets. It actually sounds a bit like loose valve clearances. Check this site out, you can use it to look up your parts for your bike. (www.nielsens.com)
- Thread starter
- #7
so i had the guy come over who was lookin to buy it from me...not running i said.. he put a kickstarter on it he had(mine is broken) and kicked it over once, dead cold start, and is sat there an idled! he told me what he did and i tried it yesterday at about 40 degrees out and it started right up! 4 years just kickin it over worked fine, i guess i gotta keep usin this new method to get er started now. weird it wont bump start will kick start though.... im using a rigged up stock steel kicker i made,
i snapped my kick started about 2"above the swivel so do you think if i got the aluminum welded back up it would hold or snap again? dad tried welding it before but the aluminum got too hot and snapped... so my top section of the lever is about 3" shorter so could i have another sectoin of bar stock aluminum welded in and not snap for a long time? it probably will only be about 10 bucks to have it welded or 120 to get a new one....any suggestiones?
i snapped my kick started about 2"above the swivel so do you think if i got the aluminum welded back up it would hold or snap again? dad tried welding it before but the aluminum got too hot and snapped... so my top section of the lever is about 3" shorter so could i have another sectoin of bar stock aluminum welded in and not snap for a long time? it probably will only be about 10 bucks to have it welded or 120 to get a new one....any suggestiones?
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