I'm just getting my 06 250 set up and the engine seems to be knocking while at it's lowest rpm/idle and at the very first crack of the throttle. It goes away if I pull the clutch in and it revs and rides great with one exception. This knock occurs while the engine is at idle on downhills or hard braking. It may just be the engine, but it does not sound right. I am going to change the tranny oil to Rotella today and try it again. I've had at least 10 seasoned riders (not mechanics) look at it and they are all dumbfounded. Comments range from "I've never heard one do that before." to "I don't know if it's an engine problem or a clutch problem." Any ideas fellas. Thanks in advance.
low rpm/idle knock
- Thread starter joey11
- Start date
I'm just getting my 06 250 set up and the engine seems to be knocking while at it's lowest rpm/idle and at the very first crack of the throttle. It goes away if I pull the clutch in and it revs and rides great with one exception. This knock occurs while the engine is at idle on downhills or hard braking. It may just be the engine, but it does not sound right. I am going to change the tranny oil to Rotella today and try it again. I've had at least 10 seasoned riders (not mechanics) look at it and they are all dumbfounded. Comments range from "I've never heard one do that before." to "I don't know if it's an engine problem or a clutch problem." Any ideas fellas. Thanks in advance.
mountain thumper
New member
imo it sounds like a clutch prob. i have an unidentified noise with mine too. im pretty sure my clutch isnt adjusted right, and im switching to rotella this oil change to see if that helps
i actually jush went to get some, but its 419 at the local parts store and i only have 405 lol
i actually jush went to get some, but its 419 at the local parts store and i only have 405 lol
SpeedyManiac
New member
Does it only happen when you're moving? If so it's the chain slapping the chain slider on the swingarm. It's un-nerving when you don't know what it is, but it does no harm.
The knock is present when it is running and sitting in neutral. It is also present when it is being ridden as I crack the throttle or when I am decending a steep hill. I have the LTR chain guide and I am positive it is not the problem. My mechanic, who use to carry gasgas, said it sounds like a clutch problem too, Speedy.So last night I drained the oil, which looked pretty bad, and had a bunch of stuff on the drain plug magnet, and I took all the plates out of the clutch and inspected everything. No wear that was unusual and no cracks that I could see in the plates. These clutches are nearly bullet proof so I didn't expect to see the problem there. I'm hoping that it is not the crank going bad. Could that be a posibility. I am going to fill it with syn Rotella tonight, and see how it does. It also has a BR9ES plug in it. I have always ran 8's in my 250's, including my 03. Could this by chance effect low end idle? Thanks for your help guys. I have an enduro this weekend and I hope to get it figured out by then, or I'll have to give the 03 a go.
I'm not sure what the dampers in the clutch basket are or the rivits, but I'll have my mechanic check them. How could I rule out the crank as a problem Glenn?
I also forgot to mention, and this probably does not have anything to do with anything, but I was told my bike has an MC ignition. Could there be a problem with that causing it to not run right at low rpms since the MC ignition is more of a high strung igniton. Like I said, it runs great at all rpms except the lowest idle.
Last edited:
I just spoke to a guy who sells gasgas and husky locally and he said he just had one do the same thing I described. The owner tried everything and installed a Wisco piston and it still did nothing to correct the problem. He installed a Athena piston with less than 2 thousandths clearance of the cylinder wall and the problem was fixed. He said wisecos are forged and have more clearance due to swelling when hot (?) I may give this a try since the bike is on the original top end. Any thoughts?
Just an update. I'm still sorting out the source of the low rpm knock. I installed an Athena piston kit and all new gaskets and the problem persisits. I called a gasgas shop and they claim it is the clutch (which Glenn suggested also) so I took the basket out and there is play when you put the gear in the vise and try to spin the basket itself. Almost a half inch of play. They said something about rubber bushings or washers (which glenn may be referring to as dampers) that get chewed up in there. It looks like the rivots on the back of the basket would hold everything in place, but I guess not. Hopefully when I get my basket back from being rebuilt, this problem will be squashed. Its been about a month of chasing my tail to figure this out. 
Has anyone else had this problem with the newer bikes? My 03 has way more hrs and its fine.
Has anyone else had this problem with the newer bikes? My 03 has way more hrs and its fine.
Last edited:
fullthrottle
New member
i have a similar noise just as you get on the throttle even in nutrel someone here told me it could be pv tention or pipe rattle on the spigot mine has had it since new
(F5)
Gold Level Site Supporter
Yes it does sound like the basket dampers (which are usually rubber of some sort). The rivets hold the basket to the plate but is designed so the plate can move & the rubber 'cushions' damp the shock. If they get sloppy then it may well rattle. On the street it would make gear changes & off/on throttle 'jerky'.
Yeah, I talked with the shop that is fixing my basket, and they said that it was a mess. One of the worst he had seen. They drilled out the rivots and took it apart to find the rubber dampners all chewed up. This strikes me as odd, since my 03 and all of the other gassers I've been around have never even needed the first clutch plate. The clutches on these bikes have always been bulletproof. I wonder if they started doing something different on the newer bike's clutches which is less durable? Can anyone speak to this?
Final update:
My bike is FIXED!!!!!!!!!!!!!!
It was the clutch dampners and if is not back together and ready to be abused. 100 mile National Dual Sport in New Straightsville, OH on Sunday. I can't wait. I'd like to thank Jay Hall for all the help. This guy is a class act. If you guys need service or parts, give Hall's Cycle a call. He knows how to run a business.
My bike is FIXED!!!!!!!!!!!!!!
It was the clutch dampners and if is not back together and ready to be abused. 100 mile National Dual Sport in New Straightsville, OH on Sunday. I can't wait. I'd like to thank Jay Hall for all the help. This guy is a class act. If you guys need service or parts, give Hall's Cycle a call. He knows how to run a business.
