Hi all, Before I say anything I want to say thanks to the club and its members for the overwhelming response I received from the posting of my question regarding the loss of compression in two of the cylinders of my 413. I guess I shouldn't be surprised now, but it still amazes me, the amount of knowledge and generosity that can be found on this email network. Thanks again, I couldn't imagine doing it without your help. Now to the problem...after hearing the responses of some of the members who suggested I need to work through the problem methodically, I decided to have the engine compression retested manually as a back-up to the computer readings that read low compression in two cylinders. After pulling each plug individually and testing each cylinder with the other seven plugs in, it was determined that compression was between 100 and 115 in each cylinder! Has anyone else experienced such a discrepancy between the computer and gauge readings? So now, what I'm left with is a relatively smooth ride when it starts up which degenerates into a hard miss, with accompanying vacume loss on the hard miss, as the engine begins to heat. Now the carburator doesn't sound so far fetched to me. But the very reputable gentleman who rebuilt the carb says that's definitely not the problem. And frankly, the carb wasn't in bad shape before it was rebuilt. Both the engine and the carb shops I know to be well-repected businesses. I'm now wondering if it could have been something that was done/or not done during the installation process. I missed the discussion about lubing the cam lobes and getting the oil pressure for the cam bearings and mains brought up before start. The install was done without me, so maybe it could have been one of those things. But then again, the compression would be off then, wouldn't it? Any ideas, assuming the compression is okay but she's still hard missing, with accompanying vacume loss? As always, thanks for the advice. 300ly, Jonathan __________________________________________________ Do You Yahoo!? Yahoo! GeoCities - quick and easy web site hosting, just $8.95/month. http://geocities.yahoo.com/ps/info1