Topica Loopframe_Guzzi Archive


Subject: Re: Coil didnt fail

Author: Martin Cooke

Date: Jun 18, 2000, 3:26 PM

Post ID: 1701063175


As the gasket compresses the head to barrel distance gets smaller. The
pushrods however stay the same length & push their end of the rocker up a
bit more, the other end of the rocker arm goes down closing the gap with the
end of the valve.

I have rebuilt an engine, set the valve clearances, driven round the block &
got misfires & no idle from a valve being held open.

Dave Otis's torque methods he posted a while back may seem excessive, but I
thoroughly recommend them as essential.

By the way, you'll never be able to tell what torque a bolt is presently set
at by applying a torque wrench & seeing what it is set to when the nut
moves. It will almost certainly take more torque than the nut was originally
set to, to get it moving. Sorry.

If however anyone knows how to determine a nuts torque once set it would be
very useful. I could certainly use the knowledge.

cookie


----- Original Message -----
From: Ian Adkins <adk-@gte.net>
To: <Loopfram-@topica.com>
Sent: Sunday, June 18, 2000 10:40 PM
Subject: Re: Coil didnt fail


 Hi All,

I suppose one good thing would be to check the valve rocker clearances
first
 before retorquing. I am not saying that you shouldn't retorque but I think
it would be interesting to see what the values are before doing the job.

By the way, that is what I did on my Ambo after the first 10 minute run. I
pulled the rocker covers and checked the clearances. So far right on the
money. I also wanted to see some oil at the top end.

Also...just wanted to report that the engine on my bike seems to be
holding
 an idle better now. I still need to do a few more runs but everything
looks
 great.

One thing I wanted to ask....how much does a head gasket compress? Is it
really significant. And as the gasket compresses wouldn't the rocker
clearances increase instead of decrease?

Ian Adkins

 
Dave's totally right here. These gaskets compress very quickly, and when
they do the valve clearances close right up. Do check.
------------------------------------------------------
 
 

Scott, if you haven't torqued the heads a few times since you started
up
 
 do
 it! I do it once after the first run around the block, once after the
first
 50 miles, again 500 miles later, you will see, that each time the
torque
 
 is
 way off, the gaskets compress severely, must be done religously.
 
Hello loopers,

I replaced the coil in my 69 Ambo, and the bikes runs great but
still
 
 dies
 
 when hot. Seems to be only when its idling. Now I am suspecting the
carbs.
 
 Maybe the heads need to be retorqued?

Scott

David J. Otis
Middletown MD
http://www.loopframe.com


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