Loss of power - 60 hp Johnson

[Ramon Alvarado]

Crusing as 7000 rpm I experienced a power loss down to 1000 rpm. Chk'd fuel filter, ok. Could it be the spark plugs? The motor was working fine for about 6 hours earlier, off and on, until this happened. What could it be?

 

[DJ]

Re: Loss of power - 60 hp Johnson

ralvarado,<br /><br />Need more info. 2, 3, or 4, cylinders-mod. year, etc.<br /><br />7000 rpm is AWFULLY fast.<br /><br />Could be a lot of things: lost spark on one or more cylinders, engine damage, etc.

 

[JB]

Re: Loss of power - 60 hp Johnson

Ahoy, Ralvarado.<br /><br />"Cruising" and "7000 rpm" are mutually exclusive terms.<br /><br />You have sorely over-revved that engine, no matter what year and version it is.<br /><br />Give us more info, but my first guess is you broke it.<br /><br />Hope I'm wrong.

 

[Ramon Alvarado]

Re: Loss of power - 60 hp Johnson

Thanks for your replys, the motor is a 3 cylinder 1971, model 60ESL71C. The 7000 rpm was registered one the rpm gage at full throtle. It starts and stays running, puttering, put will not rev higher than 500 to 1000 rpm.

 

[JB]

Re: Loss of power - 60 hp Johnson

Hi, Ralvarado.<br /><br />First, pull or short out each plug while it is running. If there is no change, that is a dead cylinder. If the engine slows or dies, that is a good cylinder.<br /><br />Check if there is a strong spark to all cylinders. Spray some fuel mix into the carb(s) for any dead ones that have spark. If the engine picks up rpm you have a gummed up carb on that one.<br /><br />If you have one or two dead cylinders that have good spark and don't respond to added fuel, run a compression check.<br /><br />Let us know what you find and we'll take it from there.<br /><br />Once you get it fixed, get a proper prop on it and never rev it over about 5500rpm.

 

[Ramon Alvarado]

Re: Loss of power - 60 hp Johnson

Thanks JB, I'll check it out this afternoon after work. Keep you posted.