Low Compression Last time I checked it


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Bob Buehler
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Posts: 71
Joined: Tue Sep 09, 2008 9:32 pm
Location: Williamport, PA
Location: Williamsport, Pennsylvania

Low Compression Last time I checked it

Post by Bob Buehler »

I'll keep the background short since some might remember where I left off.

I had installed an old RB racing draw through turbo system on my 82 and tried to get it to run right for a year or so. Fouled plugs many time but it did actually run from time to time. It never really made any boost that improved the performance which was definitely down from stock since it was such a poorly engineered system. But the bike did fire up and run most of the time (however I do recall using starting fluid and propane often LOL).

Skip ahead 4 years and I had a new fuel injection system installed. This system worked perfectly on the bike it was build on in Australia and then sent to me. I installed it and from day one had a difficult time getting it to start. Once I did get it started it did run very smoothly. I never ran it much and never brought the boost up since the motor was stock. The hard starting problem was persistent to the point that I could not get the bike to start at all and it may have sat for some time before I decided to check the compression.

When I checked the compression I got very low numbers on all cylinders and just figured I had carbon fouled the valves from previous poor fuel air problems. The bike has now sat for maybe 7 years.

I checked the valve clearance tonight and they are all with in range (between .007mm and .011mm). My next thought was to make sure the cylinders and rings have a good coating of oil on them before retesting the compression.

So the question is what to use or how. I kind of thought one of the fog sprays they use before storage would be the way to go but if just pouring a couple of ounces of 10W40 in each spark plug hole and turning the motor over by hand with the plugs out will work just as good then I'm good with that.

Any suggestions would be appreciated.

I really do not want to have a valve job done on this motor but if that is what it needs then sometime someone is going to have to do it. Maybe that would the time to have a full blown turbo ready head built.

I kind of need to or should get this bike running right before getting back into the 10 year long turbo project.

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