I have noticed a slight knock in my engine, I notice the knock the most when its warmed up and at idle, it seems to happen alot when starting it up when it is good and warm, it never seems to do it when at the ambient air temp. I have checked the valves and they were all in spec, I also looked over the cam chain very quickly and it seemed ok. I was thinking of looking at my tensioner tomorrow and was wondering what I need to look for with that? Any other ideas? Thanks.
Next time you have the valve cover off, see if you can push either camshaft from side to side (along its length). If so, you may be hearing so-far-considered-harmless "camshaft sideplay".
The sound you describe matches my experience on a '96 with a single "loose" camshaft -- versus a no-sound '99 with no sideplay in either shaft.
can this cam shaft play come in about 1000 km and be very irregular? i mean the despciption given is very similar here, but the sound occures only sometimes, i'll be checking the oil this week to see if there's any metal pieces in it (faulty bearings)
Camshaft axial play is very irregular (there's nothing that forces the camshaft in axial direction, so it can decide if it likes to knock against the axial bearing surfaces or not at leisure) It seems to be related to cold and warm engine, but there are reports in either direction (knocks cold or knocks warm).
say i will find nothing strange in my oil and the valve clearances are ok, can i assume its the camshaft paly? or are there any other possibilities?
I'd try to localize the source of the sound. If it appears in idle, you can improvise a stetoscope with a screwdriver that you set on the suspect areas of the motor, then cup the handle in your hand and hold it against your ear.
The thrust washers that ride on the surfaces of the end caps come in different thicknesses; 1.1, 1.2, 1.3 mm and "shims". I have ordered a couple of shims and the thick washer to try to make my own rattling noise at (4-6K at any temp) go away. I'll post what I find out. :cheers:
phew just inspected the oil, it's beautifully clean :) the magnet didn't find anything
the sound does come from the top of the engine, i'll try the screwdriver method..good idea thx. the thing is +-2000 km ago i accelerated very hard and instead of shifting into 2nd i shifted into neutral . :oops: it jumped into 11000 maybe even 12000 rpm i'm not sure, just very brief but enough to scare me. back than nothing made a noise and after this 'accident ' it was still quiet (as far as a gs engine can be :lol: ) now this sound comes and goes, it doesn't have any regularity. just like kerry described it. I HOPE that it's the play in the camshaft. otherwise it could be bent valves :? the weird thing is if i overreved it why didn't the sound come right after i did it :?
Not sure about the magnet. If the plain bearings are wearing, it wouldn't find anything, as these are soft metal (white metal, bronze, dunno).
However, if your knock were a bad plain bearing, it would be consistent.
Much more probale that it's really the camshaft.
And if you had a bent valve I would think you would get a constant, "fast" clatter.
On last year's BC trip I missed a shift from 5th to 6th while trying to pass someone going up a hill on my '99. The RPMs went up to 11,000+ for a second or so. My Dad was behind me, and from the cloud that shot out of the exhaust pipe he thought I had blown the engine! A few thousand miles later she's still doing fine - with no camshaft sideplay and no noise.
I first noticed the "soft clunk" at idle in my (now Richard's) '96 at somewhere around 5 or 6 thousand miles. For the longest time I thought it was caused by a loose camchain, but I never popped the valve cover to make sure. :oops: Richard has that bike up to 16,000+ miles now. We found some sideplay in the intake camshaft when we adjusted the valves recently, and also found that the camchain on his '96 seems a tad bit tighter than the one on my '99. So that wasn't it!
well this certainly will help my sleep tonight :)
untill now everything indicates to the camshaft. this summer i'm still going to check the valve clearance so then i'll be sure. untill then i just need my bike too often (actually i'll go crazy if i don't ride a day :P )
thx :mrgreen:
Yea thats probley what it is, great thinking Kerry. That is a great idea about using the stethoscope, Ive used that before to locate which lifter was bad on a car engine, a stethoscope is a very handy tool. Thanks for all the help everyone, Ill let you know if I hear anything with the stethoscope.
I've got a "real" automotive stethescope that only told me a similar noise was coming from the top end. Since I had the valve cover off and all looked well, I'm just going to ride. :) Good luck with your bike and keep us posted if you find out anything. :cheers:
I think it's one of those growing pains - noticed it at about 1000 miles and now at 2500 miles I think it's gone. Not a big deal.