Adam Savage
XS650 New Member
I'd like to preemptively apologize for this being about an XS750. I was a member of the Yamaha Triples forum, but after a slight break from the forum my account is no longer active (or something), the account recovery process kicks back with an error message and no admin email is to be found. However, from what I have found my issue seems to be one that XS's share.
Video:
This problem cropped up shortly after I had my engine rebuilt (1978 XS 750). It rode fine, I rode it from the shop back home. At the time I was still dealing with failing O-Rings and replacing them, so the carbs promptly flooded and I went in and replaced the last of the O-Rings that needed fixing. I put the carbs back on, started it up, ran.....just with a nasty tick. I figured it was just a matter of breaking in the new valve seals and everything else that was replaced, so I continued to ride it. Apart from the nasty ticking noise there are no other issues. Power seems fine, the cylinder isn't lean/rich and is tuned more or less the same as the others. I asked the shop and confirmed that it was probably just something to do with the new seals and to adjust the valves after the break in period. I did so, they were tight (which is what i was told to expect), so I replaced the shims to be within spec or slightly loose. No change in the ticking. It has been roughly 1000 miles since the rebuild with no problems other than the ticking.
I posted a similar post on a facebook group and received advice ranging from "don't worry about it" to "some really specific chain somewhere in the lower engine may or may not be a little loose".
I have checked for exhaust leaks, found none. The cam chain seems to be okay, the tensioner is all the way tight, but i hear NO chain slap from the left side of the engine. The only other strange thing is that the right exhaust has a hint of white/grey (I'm colorblind, so not quite sure. It's not black or blue. There's no coolant, and it doesn't smell like oil or gas). It dissipates at the engine warms up, and recent'y it has been cold/wet where I live so I assume it is probably condensation burning off.
I would be happy to change the Cam Chain, it's 40 years old, might as well, but could a loose cam chain ONLY effect one valve?I would think that if the chain was loose all the valves would see a change, or at least all the intake/Exhaust.
My fear is valve/piston slap. But i don't see how that could just appear out of nowhere so quickly.
Any help would be greatly appreciated., Thanks
Video:
This problem cropped up shortly after I had my engine rebuilt (1978 XS 750). It rode fine, I rode it from the shop back home. At the time I was still dealing with failing O-Rings and replacing them, so the carbs promptly flooded and I went in and replaced the last of the O-Rings that needed fixing. I put the carbs back on, started it up, ran.....just with a nasty tick. I figured it was just a matter of breaking in the new valve seals and everything else that was replaced, so I continued to ride it. Apart from the nasty ticking noise there are no other issues. Power seems fine, the cylinder isn't lean/rich and is tuned more or less the same as the others. I asked the shop and confirmed that it was probably just something to do with the new seals and to adjust the valves after the break in period. I did so, they were tight (which is what i was told to expect), so I replaced the shims to be within spec or slightly loose. No change in the ticking. It has been roughly 1000 miles since the rebuild with no problems other than the ticking.
I posted a similar post on a facebook group and received advice ranging from "don't worry about it" to "some really specific chain somewhere in the lower engine may or may not be a little loose".
I have checked for exhaust leaks, found none. The cam chain seems to be okay, the tensioner is all the way tight, but i hear NO chain slap from the left side of the engine. The only other strange thing is that the right exhaust has a hint of white/grey (I'm colorblind, so not quite sure. It's not black or blue. There's no coolant, and it doesn't smell like oil or gas). It dissipates at the engine warms up, and recent'y it has been cold/wet where I live so I assume it is probably condensation burning off.
I would be happy to change the Cam Chain, it's 40 years old, might as well, but could a loose cam chain ONLY effect one valve?I would think that if the chain was loose all the valves would see a change, or at least all the intake/Exhaust.
My fear is valve/piston slap. But i don't see how that could just appear out of nowhere so quickly.
Any help would be greatly appreciated., Thanks
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