Re: Loss of power under load

From: bob h <omniverse@...>
Date: Sun, 9 Jun 2002 16:22:40 -0500

Highspeed jets in the carb not adjusted right perhaps? And I have a tiny cam that rides along a part of the throttle linkage on mine here, don't know about others since this one is a 4-barrel inline type. So that has to be in alignment when the carb is adjusted.

I took the carb off and did all that stuff soon after I first got the boat because I too was dealing with what seemed to me to be loss of power at higher RPM. I never pulled skiiers or had any more than 3 people in it at once so it wasn't real bad. Just could tell something wasn't exactly right. Toward the end (that story summed up below) the motor wasn't getting good power enough to plane out of the water very well. That went on during several times out.

Then the electrical system went all to heck and it stopped dead. But what really happened was I had put one too many pints of oil in the 20 gallon gas tank on a long day out (I had thrown away the bottles at the marina so was unsure of count), nearly never got the boat to run but it had gotten me far out into the middle of the lake before it suffocated in oil. Next time out I put extra gas in without oil to clear the engine (I was still inexperienced, and dumb, to say the least. Note to self: Just drain tank next time!). After about a mile the boat ran better than it ever had before, the RPM's really picked up. I knew the gas was leaning it out too much by then so I was going to stop to add the needed oil. Before I could, a spark plug burned out.

My manual here tells of weak coil being one possible cause of power loss at high rpm too. But also that weak coils are often suspected yet might not be the reason.

Let's see now, fuel starvation should be checked off since it runs fine without. Timing sounds reasonable, but wouldn't it misfire? I had an old IH tractor once that had a bad governor and it lost power when throttling up but it did that in neutral too. My boats distributer just seems to twist a little; I still don't know how it works, far as the mechanics behind advancing timing while under power. Or whatever it might do. If I were you I'd give that linkage a look anyway, and make sure the distributor housing is rotating freely enough. Depends on how that specific motor is designed though and that I wouldn't know anything in the least about.

Bob H.
Received on Sunday, 9 June 2002

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