Rotating cams during desmo valve adjustment

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Cucciolo - the Lil Pup
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Joined: Mon Feb 17, 2014 5:50 pm

Rotating cams during desmo valve adjustment

Post by BultacoConvert » Fri Mar 09, 2018 10:54 am

Hi all,
It's time for my 2nd ever valve adjustment on my '78 900SD. It's been a great bike that hasn't given much trouble since I sorted it out. I was wondering about something that caused me some trouble the 1st time around. It was hard to remove the closing shims and wire collets from the valves because I couldn't rotate the cams to the point where the closing rocker can be pushed down out of the way. So I took out the closing rocker and spring to make room to get the wire collets and shim out. I like to leave the piston at tdc so I don't accidentally drop a valve in the cylinder. On the belt drive engines it's no problem remove the belt and spin the cam freely as needed. Is there a trick to do this on bevel drive engines? I'm not sure it's possible even if I remove the bevel gear from the end of the cam. I want to leave the heads on the engine and the engine in the frame.
Last time I learned to leave the closing rocker spring off while measuring/adjusting and then put it back when on I'm sure everything is set right. That way I only have to fiddle with it once per valve.
Thanks, Craig

750 Sport [BEVEL]
Posts: 218
Joined: Sat Jul 31, 2004 8:54 am
Location: Antwerpen

Re: Rotating cams during desmo valve adjustment

Post by ducadini » Fri Mar 09, 2018 11:25 pm

I always took the engine out and the heads off.
No fuss.
But yes, I needed a second pair of hands to take it out and put it back in and a set of new o-rings.
Gives you the chance to clean and inspect other stuff also.
Didn't want to go the path of removing those bevels when I put so much time in getting them right.

Nego i ricordi peggiori
Richiamo i migliori pensieri

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