1998 Johnson 50 HP - Low RPM's

[Capt.Ken]

Took my boat out a couple of weeks ago & it ran perfect. Now it starts right up, but when you go to WOT it's only turning 4,000 RPM's. Also, I took it out yesterday & when you pull it back to idle...it finally just dies. In neutral, it will rev right up. Normally ran about 6,000 RPM's at WOT. What's up? Thanks!

 

[Capt.Ken]

Re: 1998 Johnson 50 HP - Low RPM's

No replies? Has no one ever had this problem?

 

[phillnjack2]

Re: 1998 Johnson 50 HP - Low RPM's

sounds like you have dirt in the carbs to be honest.

definitely a fuel restriction.
is the choke closing off like it should ?
have you touched the litte red choke lever on the side of the block ?
(They also need to be cleaned out now and again by the way)

when was the last time the carbs were cleaned out ?
is the fuel connector on the tank definitely sealing good ?
is the fuel old and possibly contaminated ?
are the spark plugs clean ?

if this has happened all of a sudden i would say bad fuel.
if its just come out of winter strorage 100% dirt in carbs and varnished up .

also for the max revs this would be the same sort of thing as just not enough juice is getting through.

also check the prop and make sure no fishing line around the shaft of it at the back.


phill

 

[Capt.Ken]

Re: 1998 Johnson 50 HP - Low RPM's

I may have gotten some bad fuel? Tank is getting low, so i added some fuel/carb cleaner to it. Took it out yesterday & it seemed to run better, though RPM's are still not where they once were. Also noticed that my Tach & Volt gauges dropped out after a while. Cut the engine off & they come back once it's restarted. Maybe a electrical problem? Engine runs good at WOT, just not turning the RPM's it once was. Thanks for all the advice!
PS: Engine is a 1997 Johnson 50 HP. Model#J50ESL