Problem with pontoon boat rpm

[PEGCDG]

I have a 20 foot pontoon boat with a 60 hp mercury two stroke motor. It ran fine last year but this year it will not get up to desired rpm. Wide open it's get to about 3200 rpm. Last year it would run around 4400. I have not changed anything on the motor or prop. The only thing different is the anode near the prop has broken off. Would this affect the performance of the motor causing it not to plane out and achieve proper rpms?

 

[Bondo]

Re: Problem with pontoon boat rpm

I have a 20 foot pontoon boat with a 60 hp mercury two stroke motor. It ran fine last year but this year it will not get up to desired rpm. Wide open it's get to about 3200 rpm. Last year it would run around 4400. I have not changed anything on the motor or prop. The only thing different is the anode near the prop has broken off. Would this affect the performance of the motor causing it not to plane out and achieve proper rpms?

Ayuh,.... Welcome Aboard,.... Even last years rpms sounds awfully Low....

My guess is part of yer problem is, ya haven't done anything to the motor....

It Needs a Tune Up, 'n Full Service, Annually....

Ya might also need a smaller prop, but that's for another forum...

 

[scoutabout]

Re: Problem with pontoon boat rpm

Welcome to iboats, pegcdg!

That's a tough one to diagnose from the old armchair as you could have one of several problems, from fuel issues to ignition issues, to...?. Does it sound normal but just not achieving the desired rpm or is it bogging, lugging, missing, etc?

Myself, I doubt that broken anode is going to affect much, but why not replace it anyway? You don't want to have your engine starting to corrode. Related to that, however, how did it break and could there be some other impact damage elsewhere that's hampering your engine's performance?

 

[PEGCDG]

Re: Problem with pontoon boat rpm

Ayuh,.... Welcome Aboard,.... Even last years rpms sounds awfully Low....

My guess is part of yer problem is, ya haven't done anything to the motor....

It Needs a Tune Up, 'n Full Service, Annually....

Ya might also need a smaller prop, but that's for another forum...

Motor has had proper maintenance and service

 

[NYBo]

Re: Problem with pontoon boat rpm

Are you using last year's gas?

 

[H20Rat]

Re: Problem with pontoon boat rpm

Could be old gas, but I"m betting it probably is something else. When it was winterized, did they fog the engine correctly? If they did, they had the spark plugs out. So now, there is either one that isn't screwed back in tight, or they didn't connect the wire. Also, if it was fogged, it will most likely foul the plugs in the spring. (which is why its a good idea to replace plugs after the first time out every year.)

 

[Silvertip]

Re: Problem with pontoon boat rpm

If 4400 was the best you could get out of the old girl last year then you should have been looking for a problem last year. WOT on that motor is 5500. You may have more than one problem -- one of which is way too much prop for a pontoon. Not much we can do for you since we have no idea what year this motor is and if it is a Big Foot or not. Standard and Big Foot motors take very different props. If it is a Big Foot a starting point for props is a 14 x 9P.

 

[oops!]

Re: Problem with pontoon boat rpm

because he hasnt changed the prop, and he is loosing rpm.....

this sounds like a motor issue....

moving to outboards....

to the op....

please check your prop size.....even if you have not changed it....our guys in the prop forum might be able to help you, after you get this conundrum worked out

 

[PEGCDG]

Re: Problem with pontoon boat rpm

because he hasnt changed the prop, and he is loosing rpm.....

this sounds like a motor issue....

moving to outboards....

to the op....

please check your prop size.....even if you have not changed it....our guys in the prop forum might be able to help you, after you get this conundrum worked out

Found the problem. Carb linkage was loose on the top carb. The. Plastic connector had broken. Thanks for all the comments. I will be talking to someone about my prop shortly thanks