My son came home from a short ride Friday night and his bike was making some loud and unusual noises from the engine block. I took off the cylinder head cover and found this:





Would a problem with the cam chain tensioner cause the chain to be this slack? How can I check the tensioner to see if that is the problem?

Problem is most likely the cam chain tensioner. That's a huge huge huge amount of slack, and makes me worry that some damage might have been done. Minimally, I'd check to make sure that your cam timing is still correct, and perform a compression test to make sure there isn't any valve damage.

The cam chain tensioner sits underneath the carbs on the intake side of the engine between the two cylinders. There's a little rubber cap on the end, and behind that a screw. Turning the screw clockwise applies some pressure to the cam chain, and counter clockwise releases the pressure. If you turn it all the way counter clockwise, it locks in the full release position for cam service.

Also, visually inspect that your cam chain guides are okay. Only other thing I could think of is massive massive massive chain stretching, but I doubt that the chain could stretch that far without breaking.

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When adjusting the cam chain, how tight should it be???

Quote from: burning1 on October 02, 2011, 11:55:34 AM
Problem is most likely the cam chain tensioner. That's a huge huge huge amount of slack, and makes me worry that some damage might have been done. Minimally, I'd check to make sure that your cam timing is still correct, and perform a compression test to make sure there isn't any valve damage.

The cam chain tensioner sits underneath the carbs on the intake side of the engine between the two cylinders. There's a little rubber cap on the end, and behind that a screw. Turning the screw clockwise applies some pressure to the cam chain, and counter clockwise releases the pressure. If you turn it all the way counter clockwise, it locks in the full release position for cam service.

I took the tensioner off and it was all the way in the depressed position. There seems to be no life left in the spring. I did what the manual says, "turn the slotted end of the  tensioner clockwise to release the tension. Remove the screwdriver and check that the tensioner plunger springs back out of the tensioner body." No spring at all.

My neighbour is a car mechanic and he looked at the tensioner and said it looks no good. He also said timing might be an issue after this and said he would help me - I've never done that before - after I replace the tensioner.

So, are many used ones of these for sale or am I off to bike bandit again?

BTW - this is an 00 engine, yes, I'm that guy who found out the engine on the used 05 he bought is from an 00 - what year tensioners would work with this engine?

Any GS500 tensioner should work... But the device has been revised no less than 3 times since it was introduced in the 89. Ordering means you get the latest model, but you'll save a bundle by buying used.