'89 60hp 2-stroke, power loss

[dallas T]

I currently have a 1989, 60hp, 2-stroke mounted to a pontoon boat. Last summer we began to have some intermitent issues. Basically while running at nearly full throttle, the motor would loose power and drop about 1000rpm. Over the winter, the old metal gas tanks were replaced with plastic, the gas line and bulb repalced, the plugs replaced, and the carb. rebuilt. This summer, the motor still has the same intermtent problem. I think fuel delivery and "bad gas" have been eliminated and suspect some sort of an electrical issue but really do not know where to start. Any guildance would be appeciated.<br />Thanks!

 

[Elmer Fudge]

Re: '89 60hp 2-stroke, power loss

It could be a fuel pump issue

 

[bobmac]

Re: '89 60hp 2-stroke, power loss

Sounds like the problem many of us have had with 60 Mercs/mariners - believe it or not the carbs are icing up. I'll bet this only happens when it is warm and humid, right? Mercury recommended using their Quickkleen fuel additive. It didn't solve the problem. The icing problem was confirmed as "possible" by mercury marine. Next time take the cowling off and see if the carbs are sweating. Hope this helps.

 

[dallas T]

Re: '89 60hp 2-stroke, power loss

macms,<br />Thanks I will look into that. Acually it happens more often after it rains, supporting your theory. Due to the rain observation, I was beginning to think it was electrical. I borrowed an inductive RPM meter and tested when the engine was running good. With the engine running good, all 3 cyclinders were nearly the same. When the engine is running poor, 1 or 2 cyclinders reads nearly double the rpm. Any idea with this added info.???

 

[dallas T]

Re: '89 60hp 2-stroke, power loss

OK, it has been very humid here (over 90%) & thunderstorms. I was able to take it out yesterday and the problem came back. Pulled the cover off and no condensation on the carbs. Any more thoughts? Also, just received my sevice manual in the mail, the electrical troubleshooting section is not very detailed. Anyone have the proper procedures to check out common electrical components (I have a multimeter & inductive RPM meter)?

 

[bubyva]

Re: '89 60hp 2-stroke, power loss

I'm new at boating, but reading over the tune up section , I think you might be having problems with the trigger after it warms up.Seloconline.com might be able to help ..

 

[dallas T]

Re: '89 60hp 2-stroke, power loss

Just an update... I purchased another repair manual which had a good troubleshooting section. Turned out to be the switch box... Running great now.

 

[papafrancisco]

Re: '89 60hp 2-stroke, power loss

Dallas T which manual(s) did you purchase and which appear to be the better of the two?

 

[dallas T]

Re: '89 60hp 2-stroke, power loss

Seloc was the manual the helped diagnose the problem. <br /><br />I am not sure if that would be too cool to put down the other book manufacturer over the net. It was cheaper (you get what you pay for).