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Discussion Starter #1
Hi all:

I've always had intermittent vibration on my little CL350. It basically manifests in the handlebars and specifically, I notice it most in the left grip. Most of the time is occurs at low speeds/medium RPMs. But last night, I went for a ride with quite a few WOT that lasted for 10-20 seconds each. Afterwards, the vibration came back...then went away. The vibration does not manifest at WOT. It doesn't seem to matter if the bike is warm or cold; it vibrates when it fancies.

I initially suspected shitty timing, but I replaced the points and condensor and times the bike. It now has twice the power, but the vibration comes and goes. Where else should I look?

--Thanks, Chris
 

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sounds like Parks has been there

maybe you'll be lucky and they've managed to be run loose without egging out the should be round holes in the cases

and maybe the mount bolts are still round, not bent, or even worn

not a bad idea if you find them loose, or even if you find the tight

to remove them one by one and have a careful look see
 

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does the CL have those rubber mounts for the bars like the CB350 does?
i'm very sensitve to vibrations, mostly since all i have rode until recently were 4 cyl. but every twin i've riden has vibrated so much that its always annoyed me. XS650 i ride makes my hands and feet tingle so damn much that i have to stop every 30 minutes to regain my feeling in them.
I'm obviously not the most experienced esp with twins, so i'm just making sure that you're not just feeling the normal vibration that those engines produce. if your used to smooth inline 4's getting on an old twin makes you notice the vibration much more then someone that rode cross counry on one.
 

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Discussion Starter #5
Gents:

Many thank for the suggstions. I'll checkthe engine bolts. Hopefully it is something easy like that.

Hacksaw: you scare me. Hopefully it is not the ABSOLUTE worse case senario. The sheetmetal frame tabs could oval-out, but the engine holes are pretty fecking thick. Nevertheless, I'll do as suggested.

TBH, it may very well just be a function of a inline twin. But the cb360 I built was silky smooth compared to this. Then again, the 360 had rubber mounted clubmans and the 350 has clip-ons...

--cheers.
 

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quote:Originally posted by champ

hey hack, why do you space every sentence??
What, you never wrote a report in high school? Its to make his posts look longer.

Just call them electronic platform shoes.
 

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well I'll tell ya

I don't see as well as I used to for one

which in turn results in me not even bothering to read many people's posts that run on and on without even a paragraph break

gives me a headache

Then, I've done quite a bit of legal stuff and everything must be double spaced

and then, I've written motorcycle tech stuff for a magazine or two

so blame it on habit and maybe even courtesy

it surely is much easier to read than some stuff

and of course Unga is absolutely correct about the platform thing

I wish I was smartly enough to do dem htmls so all my crap could be 64 sized bold font in retina burning red

or even actual flames that burst out of everyone's monitors
 

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In addition to everything mentioned you should also check to make sure your carbs are sync'd together. Not just at idle, but that the cables both lift the slides at the same time. One slide being lifted sooner than the other will definitely make one cylinder work harder than the other, and will set up a vibration at part throttle that is not there at idle or full throttle when the slides are fully retracted.

Michael
 

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Discussion Starter #10
michael:

That is helpful because the engine is bolted tight. On the cv-type carbs, how do I make sure they are balanced correctly?

--cheers, chris
 

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Do the 350's or 360's have a balance shaft to offset the engine vibs???? If the vibs are not coming from the engine, check tire balance and chain alignment. I've also ridden bikes that just knock your fillings out with vibration and handle bar buzzing. Another reason why I like my cb-4's....
 

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Ahh - not slide carbs but cv's eh? In that case you'll just be syncing them at idle with a set of carb stix or vacuum gauges. Those carbs have all aluminum slides without a diaphram right? Check the action on those to make sure both operate smoothly without sticking. Also make sure the plastic gasket that seals the cap on isn't in upside down on one of the carbs. Set the idle mixture screws for best idle. Just basically make sure both carbs are in top shape and working smoothly together.

Probably worth double checking valve clearances, compression, etc. Look for anything that is different between the two cylinders. Sounds like you've already checked timing on both cylinders and made sure that both sides fire at the right time.

On the race bikes I balance both pistons to within .1 gram of each other - makes a big difference to vibration as there's a fair bit of variation in piston weights. Some are perfectly balanced, others are up to 1/2 gram different. Could be you got a badly matched set of pistons in there.

Or something else entirely.

Good luck!

Michael
 
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