Cam Chain Tensioner Maintenance
#1
Cam Chain Tensioner Maintenance
Question - is there any periodic maintenance you need to do on the KLX to re-tension the cam chain tensioner. KLRs have the bolt you loosen a half turn to enable the tensioner to slide over and pick up the slack on the cam chain, then you retighten. Your are suppose to do this every x kms.
I was doing some light reading on my KLX service manual to find out how the tensioner works and it looks like different design. In the KLX the tensioner appears to be in constant tension, but has a rachet which will enable it to push out the take out slack, but will not enable it to push back in, even when the spring is taken out.
It actually looks like a good design as there are fewer parts to break/bend wear etc.. (ie. the old doohiky), and with it in constant tension it appears there is no scheduled maintenance required. However, it seems like with the constant tension it could wear the chain out faster?
Anyone one have any insight? Cheers!
I was doing some light reading on my KLX service manual to find out how the tensioner works and it looks like different design. In the KLX the tensioner appears to be in constant tension, but has a rachet which will enable it to push out the take out slack, but will not enable it to push back in, even when the spring is taken out.
It actually looks like a good design as there are fewer parts to break/bend wear etc.. (ie. the old doohiky), and with it in constant tension it appears there is no scheduled maintenance required. However, it seems like with the constant tension it could wear the chain out faster?
Anyone one have any insight? Cheers!
#2
I may look more closely at 50k miles.
#5
Thats great, Thx for the responses. So im guessing unless you have to swap out a shim, you never have to remove/reset the tensioner eh?
This is a big reason I didnt go with a KTM, as much as I would love all that power, I just dont have time to wrench on my bike after every ride! Im liking the low maint setup of the KLX.
This is a big reason I didnt go with a KTM, as much as I would love all that power, I just dont have time to wrench on my bike after every ride! Im liking the low maint setup of the KLX.
#6
Question - is there any periodic maintenance you need to do on the KLX to re-tension the cam chain tensioner. KLRs have the bolt you loosen a half turn to enable the tensioner to slide over and pick up the slack on the cam chain, then you retighten. Your are suppose to do this every x kms.
I was doing some light reading on my KLX service manual to find out how the tensioner works and it looks like different design. In the KLX the tensioner appears to be in constant tension, but has a rachet which will enable it to push out the take out slack, but will not enable it to push back in, even when the spring is taken out.
It actually looks like a good design as there are fewer parts to break/bend wear etc.. (ie. the old doohiky), and with it in constant tension it appears there is no scheduled maintenance required. However, it seems like with the constant tension it could wear the chain out faster?
Anyone one have any insight? Cheers!
I was doing some light reading on my KLX service manual to find out how the tensioner works and it looks like different design. In the KLX the tensioner appears to be in constant tension, but has a rachet which will enable it to push out the take out slack, but will not enable it to push back in, even when the spring is taken out.
It actually looks like a good design as there are fewer parts to break/bend wear etc.. (ie. the old doohiky), and with it in constant tension it appears there is no scheduled maintenance required. However, it seems like with the constant tension it could wear the chain out faster?
Anyone one have any insight? Cheers!
How do I know? It happened TWICE on my KLX650. First at 5000 miles and I replaced it with a stock unit. Then it went again around 15,000 miles, but this time the cam chains were shot. Can you say "top end job". This time after conversation with the mechanics who did my rebuild (I could make more selling bikes part time than it was worth to do the work myself) I converted the stock tensioner to a manual adjust unit. That was in 2000 and was 25,000 miles ago. I've turned the adjuster bolt in less than one full turn in adjustments in that time. I've done 4 adjustments in that 25,000 mile period, doing so when I hear a slight ticking from the cam chain tower.
I can back up what I am saying with the several hundred members of the Yahoo KLX650 Group who've done the same thing, either modifying the stock unit for a few bucks or buying one from the aftermarket. The Yahoo group is the largest KLX650 specific site in the world and I am one of the moderators. I also make the part for the KLX650 for the past several months because the model had been ignored by the aftermarket suppliers. I'm one of the guys and I want to keep them going, so I do it for about half the cost of others.
I will also tell you it isn't just the KLX, it's other models too. I've been contacted by people in a dozen states along with the UK, Finland, Malaysia, and Australia - KLX, Zephyr 550&750, GPz550, ZN750, ZX6, and even an RMz450. Some tensioners just don't hold up to the stress, no matter what the claims may be. The ZX6 has been known for years to have this weak spot, it was listed in one of the used bike columns in Motorcyclist one time as a "watch for".
I'm not telling you to panic and yank it out right now. I'm saying if you hear ticking or buzzing from the cam chain tower area it will be the tensioner not working. The spring is not strong enough to hold it in, and shouldn't be. Yes the spring tension might cause minor wear, but that's not the real concern. The failing ratchet is. And it should be replaced. Do an OEM if you want to take the chance to do it twice or make/buy a manual unit.
Ride it until it wears out. It isn't catastrophic unless you ignore the noise.
#7
The cam chain tensioner will turn to junk sooner. The design looks good, but isn't. The problem is if the tensioner moves just far enough to allow the pawl to just barely pass over the rack tooth, but not seat in, backpressure under decel can and will push the rack tooth rounding both the pawl and the tooth. Eventually this can happen allowing the rack to push back and forth over several teeth very easily. It shows as the tops of the teeth being polished. The rounding can be seen under high power magnification.
How do I know? It happened TWICE on my KLX650. First at 5000 miles and I replaced it with a stock unit. Then it went again around 15,000 miles, but this time the cam chains were shot. Can you say "top end job". This time after conversation with the mechanics who did my rebuild (I could make more selling bikes part time than it was worth to do the work myself) I converted the stock tensioner to a manual adjust unit. That was in 2000 and was 25,000 miles ago. I've turned the adjuster bolt in less than one full turn in adjustments in that time. I've done 4 adjustments in that 25,000 mile period, doing so when I hear a slight ticking from the cam chain tower.
I can back up what I am saying with the several hundred members of the Yahoo KLX650 Group who've done the same thing, either modifying the stock unit for a few bucks or buying one from the aftermarket. The Yahoo group is the largest KLX650 specific site in the world and I am one of the moderators. I also make the part for the KLX650 for the past several months because the model had been ignored by the aftermarket suppliers. I'm one of the guys and I want to keep them going, so I do it for about half the cost of others.
I will also tell you it isn't just the KLX, it's other models too. I've been contacted by people in a dozen states along with the UK, Finland, Malaysia, and Australia - KLX, Zephyr 550&750, GPz550, ZN750, ZX6, and even an RMz450. Some tensioners just don't hold up to the stress, no matter what the claims may be. The ZX6 has been known for years to have this weak spot, it was listed in one of the used bike columns in Motorcyclist one time as a "watch for".
I'm not telling you to panic and yank it out right now. I'm saying if you hear ticking or buzzing from the cam chain tower area it will be the tensioner not working. The spring is not strong enough to hold it in, and shouldn't be. Yes the spring tension might cause minor wear, but that's not the real concern. The failing ratchet is. And it should be replaced. Do an OEM if you want to take the chance to do it twice or make/buy a manual unit.
Ride it until it wears out. It isn't catastrophic unless you ignore the noise.
How do I know? It happened TWICE on my KLX650. First at 5000 miles and I replaced it with a stock unit. Then it went again around 15,000 miles, but this time the cam chains were shot. Can you say "top end job". This time after conversation with the mechanics who did my rebuild (I could make more selling bikes part time than it was worth to do the work myself) I converted the stock tensioner to a manual adjust unit. That was in 2000 and was 25,000 miles ago. I've turned the adjuster bolt in less than one full turn in adjustments in that time. I've done 4 adjustments in that 25,000 mile period, doing so when I hear a slight ticking from the cam chain tower.
I can back up what I am saying with the several hundred members of the Yahoo KLX650 Group who've done the same thing, either modifying the stock unit for a few bucks or buying one from the aftermarket. The Yahoo group is the largest KLX650 specific site in the world and I am one of the moderators. I also make the part for the KLX650 for the past several months because the model had been ignored by the aftermarket suppliers. I'm one of the guys and I want to keep them going, so I do it for about half the cost of others.
I will also tell you it isn't just the KLX, it's other models too. I've been contacted by people in a dozen states along with the UK, Finland, Malaysia, and Australia - KLX, Zephyr 550&750, GPz550, ZN750, ZX6, and even an RMz450. Some tensioners just don't hold up to the stress, no matter what the claims may be. The ZX6 has been known for years to have this weak spot, it was listed in one of the used bike columns in Motorcyclist one time as a "watch for".
I'm not telling you to panic and yank it out right now. I'm saying if you hear ticking or buzzing from the cam chain tower area it will be the tensioner not working. The spring is not strong enough to hold it in, and shouldn't be. Yes the spring tension might cause minor wear, but that's not the real concern. The failing ratchet is. And it should be replaced. Do an OEM if you want to take the chance to do it twice or make/buy a manual unit.
Ride it until it wears out. It isn't catastrophic unless you ignore the noise.
#10
We're talkin bout KLX250 here folks. Not the KLR650. The "doohickey" and the failed tensioners on the KLR650 is a whole different ball o wax.
Only problem with the KLX250 is that it sometimes is noisy while the tensioner is "between clicks". No reliability issues what-so-ever.
Only problem with the KLX250 is that it sometimes is noisy while the tensioner is "between clicks". No reliability issues what-so-ever.