rough running low hour 90 ELPTO

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
I recently purchased a 21' Sun tracker Party barge with a 90hp Merc ELPTO.
the motor supposedly has around 50 hours on it.

If I slowly ease the throttle up the motor stumbles misses from 1800 to the 3500 rpm range after which is smooths out, if I just put it in gear and let it putt along it often dies, it also often dies at idle even after being ran and warmed up for quite some time.

if I go from putting along at idle and just slam it full throttle, it bogs really bad like I did nothing, then throttles up.


when we first bought the boat it had been sitting for perhaps 2 months or so, full of 87 octane, no stabil, no nothing.. ALMOST could not get it to start at the ramp.

we changed the gas out, ran a gallon of 1/4 seafoam/gas mix through it, and changed the plugs.. no appreciable improvement.

so my question is, what next? clean the carbs?

if so im pretty good with automotive engines and mechanical stuff in general, so Im not afraid to yank the carbs and clean them, but a guide on doing so would make me feel a whole lot better about embarking on that adventure.

I want to do as much as I can myself, its just how I like to operate, I don't like owning a black box, if I do all the work I learn about everything and how everything works, so when something goes wrong I don't have to go crying to someone else. Exceptions to this of course would include super specialized work requiring equipment not readily available to me.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: rough running low hour 90 ELPTO

Certainly sounds like it needs a carb clean. At 500 hours I would definitely be doing it anyway.

What year is the engine (or serial number)? We have access to PDF manuals, so if we know the engine we can direct you to the appropriate manual...

Chris.......
 

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
Re: rough running low hour 90 ELPTO

Chris, it was built in 2007.

And at 500 hours I would definatly understand the need for a carb job.
My concern is that is supposidly only has 50 hours (or less) on it.
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: rough running low hour 90 ELPTO

Certainly sounds like it needs a carb clean. At 500 hours I would definitely be doing it anyway.

What year is the engine (or serial number)? We have access to PDF manuals, so if we know the engine we can direct you to the appropriate manual...

Chris.......

I agree, mid range carb circuits are still plugged up. Once you get on the high speed jets it clears up. Just a FYI, fuel without a stabilizer is bad in a month. Outboards are really sensitive to fuel quality unlike my lawnmower that starts on the first pull with 2 year old gas. Dang Honda's never give a guy a break:)
 

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
Re: rough running low hour 90 ELPTO

I agree, mid range carb circuits are still plugged up. Once you get on the high speed jets it clears up. Just a FYI, fuel without a stabilizer is bad in a month. Outboards are really sensitive to fuel quality unlike my lawnmower that starts on the first pull with 2 year old gas. Dang Honda's never give a guy a break:)

I think what I am going to do is sort of "zero out" this motor. I.E. get the carbs done, drain and put new oil in the lower unit.. because im really starting to question how many hours this thing ACTUALLY has on it.

If I just go ahead and do everything, at least I will know, from now on, how long it has been since one thing or another has been performed and when it may be needed next.
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: rough running low hour 90 ELPTO

I think what I am going to do is sort of "zero out" this motor. I.E. get the carbs done, drain and put new oil in the lower unit.. because im really starting to question how many hours this thing ACTUALLY has on it.

If I just go ahead and do everything, at least I will know, from now on, how long it has been since one thing or another has been performed and when it may be needed next.

Excellent strategy.
 

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
Re: rough running low hour 90 ELPTO

any idea where I can find a PDF or website on cleaning the carbs?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: rough running low hour 90 ELPTO

Sorry, I misread your hours... (It was late at night and the eyes were playing tricks:D.)

For a 2007 90hp 2 stroke, download HERE. The file password is <<ribforum>>.

Whenever I buy anything secondhand I assume it has never been serviced. I do a complete service and check everything as I go. That usually irons out most problems (and potential problems.).

I have also sorted out quiet a few running problems by changing the brand of oil.... What are you running at the moment?

Chris......
 
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