1998 yamaha grizzly engine noise

Are you sure you tension correct the chain ? there is a possibility the tensioner not to tight enough the chain and remain loose and give that noise.( be careful not jump tooth out of timing.)

if you jumped time or broke the chain then it sounds like a bent intake valve. you'll have to take the head off to straighten it.

Hi Dave:
I just bought my first KLR yesterday and a service manual came with it.
Check the milage on yours??????
Really ony 2,200? That's barely broken in and amazing for a '94.
The hiss from the airbox would indicate a bad intake valve or at least that I would be checking compression to start trying to figure it out.

Did the old chain jump time or break? I think this is an "interference" engine, which means if the cain had jumped time or broke you may have internal damage--bent valves, broken pistons, etc. If the engine turns without bad noises, you might run a compression test to see if big damage exists.

You have a loose cover.

Increase in idle is usually a vacuum leak in the intake or carburetor. The poor acceleration can be a stretched timing chain that jumped a tooth on the cam sprocket or the slide in the carburetor isn't raising as it should due to bad diaphragm at the top of the piston if yours has one. Easiest way to check the carb is to remove the intake boot on the carb and watch the slide in the carb when you rev the engine. If it isn't rising up quickly when you pull full throttle then you have either an air leak in front of the carb or the slide is sticking/diaphragm is bad. There is a TDC mark on the flywheel on the left side of the engine usually found by removing a small plug or a round cover over the flywheel. TDC mark aligns with notch or pointer then remove cover on the head on left side to check the timing chain sprocket . There is a mark on the head that aligns with a mark on the sprocket at TDC (top dead center). If the timing mark is off to the right on the sprocket the chain has jumped time. You have to remove the timing chain tensioner on the back of the cylinder (two screws) then you will have enough slack to jump the chain back on the sprocket . Then replace the tensioner , release the tensioner by loosening the lock nut on top of the shaft or lock screw then retighten it. Do not overtighten or you will damage the slide inside that applies pressure to the chain. Recheck your timing marks. Sometimes the exhaust valve is bent when the chain jumps. You can check compression with a gauge or by putting your finger over the spark plug hole tightly and turning the engine over with the starter with the spark plug grounded . You must ground the spark plug or it can fry the ignition system. Good luck!

It sound like your timing is off.Have you had the cam out?Has the grizzly ever ran wright?Hope this gets you going in the right direction.
D.

if the original belt jumped you will have bent valves on that engine don

You need three things to get the engine to run. You need fuel, which you say you've got, spark, which you say you've got, and compression. You said the engine turns over but you didn't mention whether or not it sounded like it had compression. I could have some compression but not enough as well. I'd check for valves standing open or, in the case that this engine has an overhead cam, a jumped cam chain. If the cam chain jumps timing, the valves could be out of time with the engine. Sometimes you get by with this and simply replacing the chain fixes the problem. In other cases, I've seen bent valves and holes punched into the pistons. Get a compression gauge and do a compression test on the engine. Good Luck.

It definately sounds as though you've got your cam gear set 180 degrees off.When your timing is at top dead center your crankshaft will be at TDC on the guage, the cam gear will have both of the lobes at 10:00 and 2:00 away from the surface of the valve they serve on the number one cylinder. This can only be see if the valve cover is removed, which at this point I'm sure it is. Thank you, Dana