cam chain wear

[alanh496]

Hi, i just got a zxr 400 L3 from a guy that had done some club racing with it, to have a bit of fun at track days. Running at a slowish tickover, it had quite a rattle from the cam chain. Taking the pick up coil cover off, to get acess to the tensioner, it was obvious that the cam chain was a bit low on tension, which I thought must be due to it having stretched with wear. Also the tensioner was at the limit of its travel due to the that went through the hole in the tensioner blade coming up against the inside of the casting, which stopped it tightening the chain further. But I was lucky in getting hold of kawasaki workshop manual, which gives a maximum measurement over twenty pitches for a chain with the most allowable wear, and the chain is well inside this. So the obvious solution seems to be to shorten the length of the bit of the tesion adjuster that butts against the casting, to allow it to tension the chain a bit more ? The sprocket that drives the chain seems to be an integral part of the crank, which means spliting the cases to change the chain, which is a lotta work to cure a basic problem. I sure would appreciate any advice on this.

[Mori Man]

Some folks manage to remove chain as is , others trim the splash back enough to allow it to be removed - just don't grind the whole lot of, use the search function to find threads about it. You do not need to split the engine.

If the chain is within service limit then try replacing guides and the tensioner complete, this should shut it up.

Tickover should be 1,250 +-100 , however some tuning (if it's been done) requires that to be closer to 2,000 below these rev's the chain will sound clunky. Clocks can also be inaccurate so set the tickover when fully warm to where the engine sounds happy then see what the needle is indicating. Out of balance carb's will also add to the problem too so have them checked.


MM!

PS. The clutch can also sound clunky on these bikes and gets louder when the revs drop, pull in clutch lever to eliminate this sound.

[Neosophist]

I've always had no trouble getting the cam-chain on and off without cutting away the splash guard or splitting the engine.

If you remove the cams and drop the chain down to the bottom theres a certain 'knack' to it.

If you pull the chain forward at around a 45 degree angle and using an allen key or allen socket rotate the engine via the cog (forwards) and the chain will 'run off' the sprocket and drop out.

It's all about the right angle but once you've done it once it's a doddle to do.

Same goes for putting it back on... slip some of the chain over the sprocket at an angle and wind it on and the sprocket will pull it on.

Quite difficult to explain but it can be done.

Easier way what people do is use a dremmel to file the guard down (make sure you use rag to catch swarf)

Have you measured the cam-chain in 3 places? it might be stretched in a certain part.

As Drew said.. clutches are quite noisey so make sure it isn't this.. clutch in will reduce the noise somewhat.

Out of balance carbs will also make the clutch noise sound a lot worse too

[alanh496]

Thanx guys for coming back so promptly - and as mm sugested by twisting it a bit it's no problem. Why did'nt I think of that ? Something else on the bike, the carbs were secured in the rubbers using cable ties rather than the usual clips - might not be best practice, but it seems to have worked ok. Is this unusual, or is it a way of keeping costs down for people who can't remember where they put things ? Thanks again, Alan.

[Neosophist]

Yep, twisting it is the way to go.

Never seen the cable ties myself, probably a bit of a bodge by soembody who lost or destroyed their clips.