Compression Check
#3
Charter Member # 55
Charter Member
In very good shape, 140lbs with less than a 10% variance from the highest to lowest. An engine with some hours will most likely be lower, like around 120lbs. The key thing to look for is a large variance and that will indicate a problem.
#5
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This will be a cold check. Starboard engine backfiring 1300-1800 rpm and maxes out at 4500 rpm. Port engine no backfire and 5000 rpm. Suspect a faulty carb (holley) but will check # 4 cylinder- previous owner gave me heads up on this.
Wannabe
Wannabe
#6
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It would be easier to swap the carbs than to do a compression test.
Last edited by Chris Sunkin; 02-22-2008 at 03:20 PM.
#7
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Thread Starter
Take the compression tester and remove the tire valve from it. Then screw it into the hole you want to check and pressurize it. You'll have to hold the crank- a breaker bar on the balencer bolt will work. Listen in the intake , exhaust and valve cover breather. Poor man's leakdown test. If it's backfiring you may have a burnt exhaust valve.
It would be easier to swap the carbs than to do a compression test.
It would be easier to swap the carbs than to do a compression test.
Wannabe
#9
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Join Date: Jun 2004
Location: Wichita, KS
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Also, one summer I had an alternator dying on me. It wasn't completely dead but dead enough to let the voltage drop causing the engine to pop occasionally. After a long day on the water I noticed the popping got worse when I hit the trim tabs - that's when I put a volt meter on it and found the problem. The reason it didn't show up earlier was I'm very religious about charging the batteries before every trip.
Just a couple of ideas you can rule out with quick simple checks. Not likely the problem, but can't hurt to rule them out.
Last edited by ECeptor; 02-22-2008 at 04:00 PM.