Topic: 550 F high pitched top end noise (video)

[Clinto]

So I recently rebuilt the top end of my 550. It has new rings, a 650 cam, and a valve job. I've got it to a rough idle (haven't synced the carbs yet) but there is a high pitched noise coming from the top end that sounds like a really rapid tapping. Here's a video that may or may not help. You can hear the noise better further in the video as the idle speed goes down a little bit.

4-20-13

My first thought is that it's the cam chain seeing as it was always noisy before the rebuild but I think it's a different type of noise now. My second thought was the valve tappets? I used rubber bands to hold them up when I put the head back on and I think they are all sitting correctly.

Any tips?

[Tews19]

Sync the carbs adjust the valves and then the cam tensioner. Doesn't sound bad at all.

[Clinto]

I've adjusted the valves already and tried to mess around with the cam tensioner but I couldn't tell a difference after. Just a refresher, if I turn the tensioner adjuster bolt clockwise that makes the cam chain tighter, correct?

[Tews19]

It's self adjusting. I forget the procedure as I sold my 550 last year.  The manual walks you through it. But you have to use a flat head screwdriver when loosening the nut. You do not want the thread screw to move much with the nut moving at the same time. I will look for the info on it and paste it.

[rusty_tank]

Clinto, after I rebuilt my CB550's engine, during which I'd replaced the cam chain, I noticed a similar sound coming from the engine when I started it cold. I'd synced the carbs and adjusted the cam tensioner but yet there was this sound I didn't remember being there before. After talking with mechanics  I trust and realizing that the sound goes away once the engine is warm I stopped worrying about it. It's been a couple years since that rebuild and I haven't had any issues with it what so ever.

The sound coming from your engine is a bit louder than the sound coming from mine but it seems similar. Tews19 is right on the money IMHO, looking into those two things may help significantly.

I took this vid of my bike this afternoon for ya. Hopefully it makes ya feel better. Cheers

2013-04-20 18.20.59

[Clinto]

That does make me feel better about it! Thanks for the video. Its been so long since I've heard the bike running that I guess it sounds a little off to me. Another thing might be that I didn't realize how much higher than normal my bike was idling at, seeing that I haven't hooked up the tacho cable. I'll adjust and sync the carbs and hopefully the lower idle makes the sound less noticeable. If it still bothers me maybe I'll have to look into a louder exhaust :p

If anybody else has an opinion or a tip, I'm all ears. Thanks again

[scottly]

My first thought after watching/listening to the video was why is the idle speed so freaking high?  Slow the idle down. If it won't idle smoothly at normal idle speeds, check the sync.

[MRieck]

I'd put a fan in front of that engine if you are going to running it like that at a stand still. Did you replace the carb insulators and manifold orings after the rebuild??

[Clinto]

So I finally got around to messing with the cam chain tensioner bolt... after it not working like everything I've read and watched said it should and the noise not getting any better, I took the head back off

After looking at it I realize the cam chain tensioner will not stay expanded. The little gear teeth don't catch all the time, so it doesn't keep the tensioner expanded when you lock it into place. So, my cousin who is a little more mechanically savvy is trying to fix it but I'm also looking for a new tensioner. Just thought I'd update the thread in case anybody can get some info out of it later. I'm glad I took it out cause the tensioner is pretty shot

[rusty_tank]

Nice. Thanks for the update Clinto
I WAS curious how that was going for you.