1986 90hp V4 Johnson-lost power

[buckxx15]

Hi guys, Im a first time boat owner with a questions. I purchased a used 1985 18' Smokercraft with a 1986 90 HP Johnson V4 Outboard about 7 weeks ago. Things were running good until yesterday. When the throttel was at max the boat would not accelerate, it was dogging. I checked for weeds in the prop and even ran in reverse with no difference. When I got home I pulled the plugs and all 4 were black and the point spread was way off (close to 45000) I cleaned and reset the points to 33000, and also cleaned the air intake. My next thing is the fuel filter? My question is before I do the fuel filter with the plug firing so weak before will the reset help me out? Or am I missing something more important. Any help is greatly appreciated!!

 

[Joe Reeves]

Re: 1986 90hp V4 Johnson-lost power

If the s/plug electrodes were worn even at a slight angle, replace them with Champion QL77JC4 plugs, gapped at .040 .<br /><br />What is the compression readings? You should have approximately 100+ psi and that should be even on all cylinders.<br /><br />Black plugs indicate weak ignition... check it. With the s/plugs removed, the spark should jump a 7/16" gap with a strong blue lightning like flame..... a real SNAP!<br /><br />If you have weak orange or thin line blue spark, check the stator under the flywheel as that is the beginning of the ignition system as well as the charging system. If the stator is cracked and melting down a sticky substance down on the timer base and block, replace the stator.

 

[buckxx15]

Re: 1986 90hp V4 Johnson-lost power

Joe...Thank you for the information!!!