1981 Johnson 90 lost power today. I was tooling along at 47 MPH at 5600 RPM 17 pitch 4 blade prop 1981 checkmate enticer and stopped to look at something. Started it back up again and took off. Now its going 37 MPH. Pulled out the GPS and yep. Its 37 MPH . Pulled the engine cover off to see if one of the plug wires came off . Last time I changed the plugs I forgot to hook one of the spark plug wires up and it ran exactly 37 mph so I figure Ive lost a cylinder. No luck. Spark plug wire is in place. So I head back to the dock and drag it home. Ran rough at low rpm. I did a compression test and Ive got 2 at 122 psi , one at 120 and one at 115. About what it was the last time I checked. Then I had my some hold the screwdriver in the spark plug boot and see if it sparked to the block. Yep. Got spark. So I have compression and spark. Thats good. Then I check the fuel filter. This boats been laid up a LONG time and I figure maybe there was crap in the tank and it plugged up the filter. I does have fresh fuel though and tank had been drained. Nope. Filter looks good and I had my son squeeze the bulb to see if it wasnt pumping enough fuel. Made no difference. . Whats left? I pulled the carbs off looked inside and all the reeds are there and closed. OK. I dont see anything wrong with the carbs but I'll clean the bejesus out of them before I put them back on. Any ideas. The lower left plug did look oily but it didnt look fouled .
