by Rich Hammer
(Long Beach, CA. USA)
I bought my 2001 Honda Bf50 outboard with a Key Largo fishing hull used in 2013. The boat was in immaculate condition and I enjoyed 6 seasons of fishing until I let the boat sit for a year or so. I realized after a compression check on all 3 cylinders that I had a major problem. The spec says all 3 within the same range between 140 and 150 min.+/-/. So, my handy motorhead neighbor and I decided to have the cylinder head machined by a reputable shop, as we suspected the compression failure to be from a blown head gasket. Long story shorter, we replaced or cleaned the following: Head gasket and all assoc. seals, Cleaned all carb jets and replaced all gaskets and O-rings., Cleaned or in most cases replaced all aspects of the fuel tank and connections, Checked the complete fuel delivery system to the carburetor. We purchased a shop manual to guide us through the reassembly. When compression was checked after all the work described we had anywhere from 125 to 145(not real confident with our compression guage) and then after a morning of fine tuning we had the moter purring like a kitten. Boy, what a quiet moter this has always been. So we decide to take it down to L.B. for a little more fine tuning and maybe even a little fishing. This boat was running beautiful from launch, through the long slow ride through the harbor, and then we ran 35 mph(Just beautiful) toward the breakwater for about 15 min., until it just died. No notice just a very little sputter, and nothing. 30 min. later we got it started and made it in at slow speed 5-10 mph for a solid 30 min. We get the boat home and after cleaning and starting the boat with no problem we check compression and low and behold 60/45/90 W.T.H.. Why doe the engine run so well with such low compression, until it gets hot?. Any thoughts on compression guage reliability, or maybe whether the rings are my next check.