Strange noise????

[rev79xs11]

Hi All!,
I've noticed lately that a new noise has appeared in my 79sf. Usually while hauling the wife (no she's very small) under very light acelleration I hear a faint rattle. It's hard to describe but the best I can do is to say it sounds like dragging a light chain across the edge of a tailgate. Not real loud, wife doesn't even hear it. Seems to go away under harder accel. I've adjusted the timing chain already, no change. Could it be the primary chain? Has anyone else had this problem?


Any help is greatly appreciated!

Ron Evans
79 xs11sf
85 honda vf500f

[strom]

Check out your rear wheel, middle and final drive bearings. Change the oil in there first, and see how it comes out. If it's XSivly dirty and full of metal shavings, there's your problem. Check it out ASAP, my 78E PO had his middle drive lock up at 75 and it's a miracle he didn't crash. Also check out the U-joint and lubricate it while you're at it.

LP

[fxrer]

Is it an engine noise, or drive train?

If engine, check the timing. If it is slightly too advanced, you can hear the onset of pinging, which sounds like a rattle from the top end.

If you try premium fuel, and the rattle lessens, that could be the source.

[rev79xs11]

It's hard to pinpoint because it only happens under load. Mostly mid rpm's most noticeable in 2nd and 3rd gears. I'd have to say it is engine in nature, sounds like it is foreward and below me.

[skids]

How do you lube it Strom?

Originally posted by strom
(snip) Also check out the U-joint and lubricate it while you're at it.

LP

[xssiveone]

Originally posted by skids
How do you lube it Strom?

It's just a standard automotive style universal joint. Remove it from the yoke and take the ends off. (CAREFUL here as there are tiny pins (needles) in each cap. ) Clean, and regrease.

Something I was thinking about, but never got around to doing, was drilling the U-joint and tapping for a zerts grease fitting. That way you can give it a shot or 2 of grease every spring. Never got beyond the thinking stage, so not sure if there would be room for this or not.

[Douce]

Let me know if you find out what it is.
Mine does the same thing.

[pggg]

Xssiv, I installed a car U-joint with the grease nipple in my XS11 but the nipple clipped the inside swingarm once spinning. Had to unscrew the nipple and plugged up the hole with epoxy. The car U-joints work well and are 5 times cheaper than a yamaha OEM.

[xssiveone]

Originally posted by pggg
Xssiv, I installed a car U-joint with the grease nipple in my XS11 but the nipple clipped the inside swingarm once spinning. Had to unscrew the nipple and plugged up the hole with epoxy. The car U-joints work well and are 5 times cheaper than a yamaha OEM.

What I was thinking as well... car joints would be much cheaper then OEM ones, provided you can find the right size, which obviously you were able to.

You don't happen to know which car they were meant for? Make it easier if there was a particular model to ask for.

How did the grease fitting clip the swingarm? The ones I've seen with grease fittings, the fitting is in the center (web?) portion of the joint. Was yours in a different spot?

[pggg]

Xsv, didn't get the part number for those car U-joints sorry. I remember taking the bikes' original to the auto shop - a suspension/wheel alignment place - and just compared sizes until we found the right one. Only features are "Made in Japan" and "Toyo". Big help huh? Grease nipple on one outside cap. The original OEM has no internal passages, so no go for greasing.

[rockjok]

I've noticed a similar sound under certain accellerations. After a while I found a crack in one of the heat shields under the footpegs. If I put my foot on it the sound disappears. Another possibility......

Rob