WTF is this thing?

[smthng]

WTF is the alien looking contraption on my throttle-side cylinder (see attached pic)? Me and several friends have been trying to figure it out without pulling it off. I've checked the Yamaha parts diagrams and can't find it. Any ideas? This is just something that's been bugging me. If the picture doesn't make it very clear, here's the best I can do for a description...

This "thing" is hanging off the back of the cylinder on the throttle side, right above the clutch cable lever. It's a "cylinder" with a screw on the end of it and is mounted to the engine case with two bolts. The only identifying mark is the word "UP" on the top of it (good place for that I guess).

Sorry if this post should be in a different forum... if I knew what the "thing" was, I'd probably know which forum to post this in. But, then I guess I wouldn't need to post. Ah well... moderators, feel free to move this if needed.

[sportryder]

That "thing" is the cam chain tensioner. There is a specific procedure for taking it off unless you want to learn how to put it back together again without any instructions. If you don't know, don't touch it.

[smthng]

Originally posted by sportryder
If you don't know, don't touch it.

That's why I was asking before breaking out the ratchet set.

Nice work, I was betting a friend I'd get an answer in 15 minutes... you beat it by 2. God, I love this forum!

[Fade]

7 5LV-12210-00-00 TENSIONER ASSY, CAM CHAIN

[sportryder]

Originally posted by smthng
That's why I was asking before breaking out the ratchet set.

Nice work, I was betting a friend I'd get an answer in 15 minutes... you beat it by 2. God, I love this forum!

Here's a tip. If the gasket ever starts to leak where the tensioner connects to the cylinder head or you remove it for some reason.

If you remove the 10 mm bolt on the end of it and insert a thin flatblade screwdriver and lightly turn it clockwise until it bottoms out. Then, tighten just a bit more and it will lock the tensioner spring loaded plunger in place. You can then remove the two 8 mm bolts and carefully pull the tensioner assembly away from the cylinder head. To reinstall it, repeat the steps in reverse order being careful to check the gasket surface for dirt, debris and condition.

If there is no need to remove it other than your curiosity, it's best to leave it on and not risk tearing the gasket. There are no performance gains to be made with it unless it's malfunctioning and if it were, you would hear bad things coming from the cam cover and cylinder head area.

[smthng]

Fade, thanks for the diagram... I was looking at the engine diagrams and didn't spot it. Without knowing what it was, I wouldn't have thought to check the cam pages.

Sportryder, good tip, but probably beyond my meager abilities. Some day that might be useful for ME to know, but not today.

[todd1qaz]

For some reason while removing my carbs for a jet kit upgrade I decided that it would be a good idea to remove the cam chain tensioner.
When I pulled it out the plunger was fully extended and locked in place. To get the part back in the bike I had to adjust the tensioner so that the plunger was not fully extended.
Does anyone know if further adjustment is needed prior to start up or will the tensioner readjust on its own?

[RavenRider]

If you got it retracted and properly installed,then released the plunger to allow it to apply tension to the cam chain,that's it.

The tensioner will self adjust from there.

[todd1qaz]

Thanks Glenn,

Got it.... The bike is just about back together. Too bad that winter won't quit. Going to Red Lake in the morning to clean up on some giant crappies. Hope it warms up next week.