Topic: "oh my god. is this bad? is this bad?"

[hawkeye]

so I'm not sure if this is normal or not but when I get up to about 4000 rpm or a little below my bike sounds a little like what a can of bolts put through a kazoo would sound like.  it seems like it's coming from the exhaust.  is it the baffles rattling around in there or what?  anybody else have this problem or been able to do anything about it?  or am I out of my mind?

[mick750F]

   Have you adjusted your cam chain? I've disected an F2-F3 muffler and they're pretty solid in there. I'd expect them to rot out before anything inside loosened up enough to make a lot of noise.

Mike

[hawkeye]

I guess I should mention that it's sort of a buzzing sound.  As for other problems with the bike in case it's all related, the choke seems to be out of adjustment, idle is real rough and needs to be constantly adjusted, it bogs in 1st coming from a stop, and I pulled the plugs today and they were grey.  yeah, I know I have some work to do.

[hawkeye]

   Have you adjusted your cam chain? I've disected an F2-F3 muffler and they're pretty solid in there. I'd expect them to rot out before anything inside loosened up enough to make a lot of noise.

Mike

yeah, actually that's what I was doing all evening.  it seemed to help with some of the rattling from the front but that buzzing is always there.  it's more of a weird exhaust note than anything.

[hawkeye]

oh, and one more thing I forgot.  I've been using 89 octane which is stupid but I'm so used to filling up with the cheap stuff I never bothered to think that it might be causing problems.

[mick750F]

I guess I should mention that it's sort of a buzzing sound.  As for other problems with the bike in case it's all related, the choke seems to be out of adjustment, idle is real rough and needs to be constantly adjusted, it bogs in 1st coming from a stop, and I pulled the plugs today and they were grey.  yeah, I know I have some work to do.

   Yup, you have some work to do because it is indeed all related. A complete tune up is in order which, judging by your symptoms, should include a disassembly and cleaning of the carbs with particular attention to the jets. Poor performance on these bikes can often be attributed to one thing out of sorts in the tune-up procedure.

   And yes, you're out of your mind. Otherwise you wouldn't be here.

Mike

[BobbyR]

This may sound strange but my right hand mirror buzzes like that at 6K RPM, it sounded like exhaust to me at first. I should figure out how to stop it, but I kinda use it as a shift indicator odd as that may seem.

[hawkeye]

Thanks for the replies guys.  I'm ordered the yamaha carb cleaner today and I'm going to tear that sucker apart.  I've done everything with the plugs, timing, valves, etc. so it's pretty much down to these darn carbs.

[gaijin]

Mine does something similiar around 2.5-3k. After a lot of searching for loose bolts and head scratching I found the source. I went to pull the silencer off one day while working on something else and found it was broken off.  So right before it went into the clamp at the collector the two seperate pieces were just sitting next to each other. I haven't fixed it yet, since A) I haven't been able to remove the broken off bit from the collector and B) I'll have to weld them back together once I do. Which actually won't be hard, but it's one more thing to do.