Subject: Re: Guzzi machinists near Sacramento, San Francisco CA?
Author: Greg Field
Date: Mar 24, 2005, 7:28 AM
Post ID: 1718593413
Pull off the heads. I bet your bores are very worn at the top of the
piston's stroke. This is the most common failure mode on the chrome
bores, in my experience.
GF
On Wednesday, March 23, 2005, at 10:45 PM, gerar-@netzero.net wrote:
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The air compressor I used was quite small. I found that the TDC mark did not move after I did the leak down test. I had to rotate the crank all the way to the most advanced timing mark before the compressor would push the piston down.
I am aware of that. I set it at TDC by rotating the crank at the pulley under the front cover while holding my thumb over the spark plug hole and waiting to feel pressure building. Then I set it at the timing mark for the #1 cylinder and to another scratched in mark for TDC for the #2 cylinder after feeling compression develop in the #2 cylinder.
I built a primitive leakdown tester similar to the one shown at http://vmaxoutlaw.com/tech/leakdown_tester.htm. I could not get the porcelain out of an old spark plug, so I used the spark plug fitting from an old extra compression tester and used that. The gauge was reading only 10% retained air. I sprayed down the tester and line with soapy water to see where air could be leaking, but there were no bubbles. I also noted the air was clearly coming out of the oil system, NOT the valves. Granted, if I held my thumb tight over the spark plug connector, the gauge would only show 30% retained air. That's when all the other connectors on the tester would start blowing bubbles when sprayed with soapy water! I suppose I should order a tester online. Thanks so much for the offer, but I'm reluctant to drive up and back when I can lazily punch some keys online! :)
Yes. We did the test several times. Incidently, I repeated the test before I responded. Different compression tester, similar figures. Hmm. I confess a certain amount of frustration with the idling. I have rebuilt the carbs, rebuilt the distributor, set the valves, timed the ignition, replaced the exhaust with stock pipes. It seems like I've done everything except fix the compression, so perhaps I've got a hammer and everything looks like a nail. Gerard Your free subscription is supported by today's sponsor: ------------------------------------------------------------------- Help us support US Troops � Just Register Here. http://click.topica.com/caadjGFb1dfltb6KFeCf/PermissionData ------------------------------------------------------------------- |