'88 90hp lost power

[bostonmike]

I have an 88 Johnson V4 90hp. It has run fine all season, had the carbs rebuilt, spark and compression test done at the beginning of the year. This past weekend after being out for about 7 hours, I was running WOT when suddenly it cut back to about half speed and then died. It started up again without a problem but when I pushed it to full throttle it ran about half power at best. I was able to get back into harbor without a problem, it was just very slow going.

When it died I didn't hear anything pop or crack and there was no smoke coming from it. After I got home I hooked it up to the earmuffs and it started with no problem again, went into gear fine. I pulled the four plugs and the two in the top cylinders were fine, but the two bottom seemed like the oil on them was a bit watered down.

Does anyone have an idea on what my problem may be? I'm hoping it may just have gotten water in the intake or gas? Hoping it does not require a rebuild or anything too expensive.

Thanks for any insight!

 

[ob]

Re: '88 90hp lost power

My first recommendation is to perform a spark test to insure that all four plug leads will jump a 1/2" gap to ground at cranking speed.Should produce a crisp blue spark with a snap.

 

[hoeser]

Re: '88 90hp lost power

When you say the bottom two were wet, do you mean the bottom on the port side AND the bottom on the starboard side? If they are both actually wet (with water), that's a little strange. I'm hoping you just identified the substance incorrectly. Most likely it's an ignition issue and they were just soaked with unburnt fuel. As OB suggests, spark test time.

 

[tashasdaddy]

Re: '88 90hp lost power

also check the compression on all 4, post the numbers, and results of the spark test. i have the same engine without VRO. did you have a strong pee stream?

 

[mlindberg1]

Re: '88 90hp lost power

I have the same problem with 1993 Johnson 88 spl.
I hope it is water in the fuel but when I emptied the fuel out of the seperator into a glass jar, I did not see any water.

Any help woud be great.

 

[bostonmike]

Re: '88 90hp lost power

I could be wrong and it could be unburnt fuel on the plugs. I had water pumping strong out of it all day, before and after the problem. The two lower (port and starboard) cylinders were the ones with the "watered down" oil on the plugs. Also I don't have a fuel/water seperator if that helps any.

I'll try to get it in for a compression and spark test.

Does anyone know if this is possibly a blown cylinder or crack in the block? Someone had mentioned this to me as well, but I don't know enough to narrow it down.