140 Johnson Bogs Down Over 3,000 RPM- But Is Fine After I Tilt The Motor Up For 2 Min

[nypbbob]

Hi folks, great message board... I finally have a question.....

Never had problem with the motor. ...... Rained cats and dogs for three days straight here in south florida... Took the boat out, was running awesome all day (six hours) at 4,000 rpm's, 38mph... Then all of the sudden it started boggin down... I turned the motor off and tilted it up to check the prop, etc, and all was fine.. Tilted it back down after 2 minutes and I was able to get up on a plane for two minutes tops then it bogged down again.... (note: pump ball was hard)

Took the boat home.... Check fuel/water seperator and seemed pretty clean, checked all electrical wiring etc...

Then we took it for a bay test the next day, started right up, no problems, idle speed for 20 minutes and then I planed it right up and after two mintes or so BAM, it bogged down again... We took the air box cover off to expose the carbs... We sea fomed the piss out them in gear,e tc., etc... Changed plugs.. Cleaned carbs again... ran idle speed for 20 min... Got up on a plane for guess how long? yep, two minutes it started to bog down again.. (when we had the cover off and checking out the carbs with the throttle up, fuel was pumping just fine.....)

OK, then turned the motor off and tilted it up again for two minutes then back down, then puched it out... Got up on a plane again, then after two minutes once again it bogged down (note: it never stalls just cant throttle up past 3,000rpm or so)............

Any thoughts?

Thanks!

[boats.net]

Its really hard to say. Seems that you have covered all the basics. Are you certain its not over heating?

[nypbbob]

I dont think its overheating, the buzzer did not go off. Is there any other way to check? The motor itself never was to hot and the water pissing out of the motor was luke warm at best....

ps- thanks for the reply

[boats.net]

Then no wasn't overheating. Start testing all the ignition components.

[nypbbob]

I think we may have found the problem... I had a problem with the tilt wiring in the throttle base and disconnected them a few weeks ago and slapped electrical tape on it to cover the "hot" wires.. Well, when we were checkign the ignition switch out, we noticed when the throttle was pushed all the way forward it was arching and arching bad because the electrical tape fell off the wires mentioned previously. When we pulled back the throttle the wires were not arching anymore... So i re-did the wiring and we are going out tonight to check it out.. Im hopeful that was the problem-- and it makes sense because the only time the motor bogged down was when i had the throttle all the way forward and ran fine when i pulled back on the throttle...

Hopefully this is the problem..

[nypbbob]

well it worked for 5 miles and damn she was fast as hell probably because of the carb and other works completed.... but then after five miles she starting boggin again (never stalled).... im really leaning towards electrical and or over heat... my buzzer may not be working right, what are the signs of overheating or a cylinder getting to hot? thanks again

[gasman]

steam from the exhust and pull your plugs look at the ends if there over heated get a infared thermomoter inexspentive at harbor freight