Hi. I'm looking for some advice.

I bought my 2009 KLX250 second hand. For whatever reason the automatic timing chain tensioner had been modified and converted to manual. The spring loaded extending arm has been removed and the center drilled out and tapped to insert a regular steel bolt which can be manually tightened to increase the tension.

I don't know who did this or why and have no way of knowing whether the bolt is longer than the original extending arm. If it is, I'm concerned that continuing to tighten it when the chain is slack will eventually break the chain. I'd prefer to switch to a regular auto tensioner.

I live in SE Asia and getting OEM Kawasaki parts is difficult (and expensive in proportion to the value of a 14 year old bike).

There is a very common Loncin YF300 engine which is a Chinese clone of the KLX300/KLX250. These parts are much easier to get (In many cases if I try to find and pay big money for genuine Kawasaki parts, it's likely these Chinese copies are what I will receive anyway as there is no official Kawasaki network here.)

Has anyone been in a similar situation and ordered a YF300 tensioner for a KLX250? I was thinking trying that before going down the more difficult and expensive OEM import route. Can anyone confirm that it's compatible or not?

Thanks

 

Here's a link to directions.

KLX Cam Chain Tensioner Directions

 

Thanks for the info. The bike has a manual tensioner. I want to go back to a standard automatic tensioner and am trying to confirm whether the tensioner from the cloned Loncin YF300 fits a 2009 KLX as the Chinese parts are much more easy to obtain (and cheaper).
Can anyone confirm whether the tensioners are the same?

 

Biggest question in my mind is why? It's not like the KLX is rare enough to have collector value in stock condition. The OEM isn't dependable as proven by the fact that I am getting orders from riders with the new 300s as well as 250s. If it is about directions for the manual one I can provide that with this link to a google document click here. I just don't understand the step backward. Unless some mechanic without any understanding of the cam drive is telling you to do so. Heck the manual set up has been reliable enough that Yamaha had it on the SR400 and 500 since the first one in 1978 and I believe the XS650 also used a similar set up. Racers use them for reliability as well. That's how I got into it the mechanics I knew were a former drag racer and the other a flat tracker, their suggestion.

But in the end the choice is yours for whatever reason. I hope it works well for you if you go back to the auto setup. I guess you always have the manual one to fall back on if the replacement fails.

 

As soon as my fails, I'm going manual!

 

Buy Oem and change every 5000 miles

 

Do the stock ones really fail that often still? How many miles do they typically fail at?

 

Thanks for the info. I'm not interested in buying another manual tensioner. I'm looking specifically for an automatic one. Does anyone know whether the Chinese clone for the Loncin YF300 is a direct fit?

 

I I spent about an hour looking for the Loncin tensioner, finding some images, but I can't tell if it has the same off center set up.as the original. They don't show a photo that is from front or rear. The plunger on the OEM adjuster has two cuts across the face making it work for an off center positioning, plus the center of the plunger is offset as well. You need to see the part head on or tail on to see if it is right. Or just buy one and if it isn't right return it.

Thing is you don't need to buy the manual adjuster, you told us the one in the bike has been modified. If the bike ran with that set up, use it. You just need to know how to adjust it.. You could read the directions for adjustment and follow them carefully. It isn't hard, but you have to realize it is only adjusting the chain slack out, therefore when done properly by finger tip you will have the chain slack adjusted out of the drive with virtually no tension on the chain - which is correct. The bolt is actually loose enough to be loosened by hand. The lock nut that should be on the bolt, which is tightened down against the body is what locks in the adjustment. Read the adjustment part of my directions and you can easily do the job. Cost is zero since you already have the set up. One last time... read the directions for adjustment in the instruction link I posted for you.

The OEM has a spring that only puts on enough pressure to push the plunger forward if there is any slack. The rack and pawl are to lock in the adjustment, but when they have the teeth and pawl worn a bit they quit working and the spring is not strong enough to hold the adjustment. If the spring was that strong it would exert so much pressure as to put too much tension on the cam drive. So look at those directions and see if you can follow them with the set up in yours. You should be able to.

 

Thanks for your time looking at the Loncin images. I appreciate it.

There's no problem with adjusting the manual tensioner that's on the bike. I want to replace it because:
A - It leaks significant oil where it has been bored and tapped to install an adjustable bolt instead of the automatic plunger.
B - It is not well made and I suspect the length of the bolt used to apply tension is probably different to that of the OEM's plunger. If longer than OEM it will continue to apply tension to the chain when the chain is beyond its useable life and risk breaking the chain. If the bolt is too short, It will mean replacing timing chains before they are expired.

I plan to replace it and am not interested in replacing it with another non-OEM tensioner so my options are the standard Kawasaki auto tensioner which is not available here so would have to be imported, or, the Chinese clone which is available and cheap. As the Chinese top end kits have been around for a while I was hoping someone might have experience with the tensioner.

The Loncin images I've found give the impression the external side of the tensioner is off center while the wider internal side seems to be centrally spaced between the two mounting bolts. I've also now found some measurements for the Loncin part so will remove my KLX tensioner tomorrow for comparison.