Questionable squeak

Just recently I noticed a squeak emanating from my engine (I think... could be the carbs, it's hard to tell) that increases in speed whenever I roll back on the throttle. It's not a harsh noise, nor does it sound like anything rubbing... just squeaky. And, it appears to be coming from the left side of the bike.

There's no loss of power, no weird power problems, just that squeak. I wouldn't mind it so much except I'd like to know where it comes from.

Any ideas?

I posted a video on my blog that captures the noise pretty well.

 

I think that I'm working through the same problem you have. My intake manifold has what I think is an air leak that makes a distinct "squeak toy" sound. I PM'ed chacal about the O-ring that goes under the thin rubber gasket. I'll have to dremmel the old one out, it has the consistancy of cold roofing tar but, I've already verified that there is a metal seat that the O-ring sits on, (I tore into an old one to check it out). I might have to use some High Temp RTV to make the seal, I'll let you know.

Cheers
Ken

 

I recently replaced all 4 gaskets and wondered about those o rings but chacal told me they didn't need to be changed. That's a possibility though because when I took them off they weren't in pristine shape. Definitely irregular.

I'll be waiting to see the results of your research. Did you listen to my video file? Are the sounds similar?

Thanks,

Eric

 

Hey Mad
Yeah I listened to the video. Nice blog. The sound is the same as I have however, I think mine might be worse, just a bit louder & different pitch. Were you able to take care of the sound? Also, did you use the "official" gasket only or, a cut gasket, and, gasket sealant, one side or, both sides? I'm wanting to get mine done today. I already cut new gaskets but, not sure if I should use those or "offical" gaskets.

Cheers again
Ken

 

I had a similar noise.
It turned out to be a rubber cap leaking. It was on a vacuum line on the left side of the motor right in plain view.
The noise gets quite irritating after a while....

 

The gaskets were much thinner than standard gaskets and you don't need to use sealant. Just lithium grease. I don't know why you couldn't use The gaskets you cut out.

Did you notice a decrease in power, or your rpms hanging? I didn't notice any of those things. Prior to changing the gaskets, there was a significant hang.

Good luck. Let me kniw how it goes. And be careful takingnthose manifold boots off. I didn't have any issues, but apparently the bolts break easily.

 

I took a quick peek at mine but I did t notice anything amiss. I'll definitely look a bit closer though. ThAnks!

 

I Just got finished doing the propane thing with no discernable differences. I'm gonna try some flamable brake cleaner to see if that penetrates to where my leak is. Chacal told me that there was no O-ring, what I was seeing was an integral part of the manifold but, that I should first try to sand off the old gasket material on a flat steel surface to get a better mating surface for the gasket to seal. I've already taken off my manifolds once and, when I installed them I made sure that I used some "Anti-cease" when I re-installed them so, I shouldn't have a problem with any broken bolts (hopefully!!!!!!) Hey Maz, I already bought 3 new boots to cap off my vavuum lines so, I hope that they're not the cause of the problem. I've even tried to isolate the sound further by using the screwdriver stethoscope, I got better isolation just from sticking my head closer to the cylinder head. Gonna try and find that damn squeeky toy sound!! I did check out the other areas of the mill just to insure that the sound wasn't a bearing, thank the good Lord that's not the source of my problem. I'll letcha know what happens when I do the break cleaner thing but, I'm sure that I'll need to install the new gaskets that I cut.

Cheers all
Ken

 

Well to up-date you on my similar type problem. I took off my intake manifolds, sanded them flat using a piece of glass for a flat surface & some 220 grit wet/dry sand paper to remove any old gasket material that O-rings up with the new gaskets. I then used some Permatex Hi Tack on the manifold surface & the side of the gasket that mates to the manifold. That seemed to take care of the "squeak toy" in my bike. I feel fairly confident that the new gaskets will take the heat and remain sealed, if not I'll update this post.

Cheers all
Ken