Johnson 150, 2500 RPM max

[shane772]

So the original thread about a WOT problem is at the link. Turned out to be a power pack.

New problem. Into a 10mph head wind boat won't plane or get above 2500 RPM. Tail wind it will plane and max out at 4000 RPM. Runs nice at 4k rpm, no miss like before. Took it back to the shop and we'll see what they say. 4 weeks and $900 out of pocket so far with still no boat. I will update this thread in case it helps someone in the future.

 

[Silvertip]

Either the engine is not making full power, throttle not opening fully, or it is severely over-propped (way too much pitch). That engine should easily rev to 5500.

 

[shane772]

I checked on the lake today that the carbs are opening all the way. Has a Raker 24 and it revved to 5300 or so before the power pack so I don't think it's a prop issue. My opinion is the kid working on it has it timed wrong. But I have no clue, LOL

 

[boobie]

Take it to a different mechanic !!

 

[shane772]

That's probably good advice . . .

 

[shane772]

Update: Shop couldn't get more than 2500 rpm in the tank. Checked carbs and they were FULL of nasty. Rebuilt 6 carbs, sync'd etc. Took it to the lake and it's running GREAT. New power pack + labor was ~$600. 6 Carb rebuild, new T-stats + labor ~$1000.