I think I know why many people run extremely short pipes

emzdogz

Aunty Em
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So they don't have to hear the valve clatter!!!!!

Took mine ('80) out for a short test ride yesterday, after having made a new tail light mount and getting carbs refurb'ed. Ran pretty nice, really! Clutch works great. Brakes, not so good - they are spongy, so I will re-re-re-bleed them yet again.

I just went up and down a few streets in my neighborhood and went without a helmet, and dang, the valves are more audible to me than the exhaust! I'm running long drags with baffles in them. They're still pretty loud, but being so far back from where my ears are, I just don't "hear" the exhaust much while riding, unless I rev it real high.

Thinking that short pipes, that end just past footpegs might supply a bit of cover-up for the clatter of the valves (which are set correctly).

This isn't the first bike I've had the issue with, either. On my Sportster, I was happy to get some slightly louder slip-on mufflers, which masked the valve train mechanical noise. And on an earlier Sporty I had, I removed the windshield, because it just reflected all the valve noise back into my ears.

Now I know on a normal ride (where I'd be wearing a helmet for sure) it wouldn't seem that loud. But this just sounded like nuts and bolts rattling in a can, (rhythmically, of course).

Going to try the cam chain tension adjustment again, see if I can get it a bit more quiet. Funny, I don't remember my old '79 (which was my main rider for awhile) having that noisy of valves.
 
emz I dont think its your valves that you are hearing . I think that you plastic has come off your cam chain guide and you are hearing the chain hitting the guide.Here is a video of mine when that the cam chain was hitting the guide after the plastic came off and fell down into the sump.
 
wow I think you are right! sounds just like that.

So I guess when engine comes out (for paint and all) I will go ahead and repair that. Funny tho, I had just drained oil (because crank case had over-flowed with gas when my carbs were messed up) and didn't notice any plastic chunks in ...

thanks. Yes that is the noise, alright....
 
Carbon, did you replace your front chain guide yet? I am doing a rebuild on mine and was debating on replacing my front guide. I went to the local Yamaha dealer and they quoted me about $90 for the part! My original guide has obvious wear, but I wouldn't say its in bad shape, and I honestly dont know if its worth the $90 to replace it. I don't exactly have any spare money right now.
 
Yes I have replaced the cam chain guide. It was the first time that I had taken this engine apart but all went well. If I was you and the guide was 30+ years old replace it..
Install it before you put the jugs back on that way you can make sure that it is centered in the tunnel.after I had put mine on I was told abut centering the guide .so I took it back apart and centered the guide. And Im glad I did it was off center just a bit.
 
$32 at 650central :thumbsup:

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I wonder if they may have looked up the wrong part for me at the dealer? Either way, its definitely worth it if I can get one through 650central.

Thanks for the tip about centering the guide, its advice like that which is good to learn before the project that makes everything go more smoothly.
 
"stealer" not "dealer"

Search the forums, those are on back order everywhere, but a few people have noted where they're available. I think the price at said places is inflated, about $60. As Ricky would say, "supply and command."
 
"I think I know why many people run extremely short pipes"

I always thought it was to make them look taller. I guess I'll never stop learning.

Tom
 
:shrug:Ignored noise in my 75 XS to my dismay .Going up the Bombay summit went to down shift and missed the shift, red lined it then noticed a clatter coming from the valves kept on riding till I made it home. Took off valve covers and noticed left intake valve adjustment screw missing,found the nut though but no screw. Think it may have ended up in the sump down through the cam chain slot.I do not want to pull the engine but just enjoy the Kootnay mountain rds.Does anybody think this may prove to be a problem?
Thanks Schick 1st time poster.
 
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