Bad prop or Bad labor

[creekslick]

My step-son has a 115 hp Suzuki 4 stroke on his pontoon boat that has run fine for 1 1/2 years now. When we took it out the first time this summer it would get up to 6000 rpm and then all of a sudden it would drop down to 5000 rpm for a second or two then pick back up to 6000 rpm. It did this several time so I told him I thought he had gotten some water in his gas but he said the marina has winterized it last fall so the fuel stabilizer should have removed any water. I suggested we add some stabilizer to see if it would help so he did but we did not get to run it after that. This past week he called the marina and told them he was having a problem with it. I took the boat out today and it ran fine so I called him to let him know that all was fine with it and that is when he said the marina had called and told him there was something wrong with his prop that was giving him the trouble. My question is how can a bad prop make a boat loose 1000 rpm then pick back up and loose it again over and over? I think they did not winterize the motor but charged him for it and came up with this prop thing just to cover their butt.

[speckfinder]

does not sound like a prop problem

[CatFan]

If the hub is bad you can get RPM variations as the hub slips and holds.

No matter what was put in the gas before storage, I wouldn't run it if it's been in the tank all winter. Drain the old gas and put it in a vehicle, and buy new for the boat.

If the boat was winterized, it's likely they fogged the cylinders. That usually requires new plugs the first time you run the motor.

[creekslick]

If the hub is bad you can get RPM variations as the hub slips and holds.

No matter what was put in the gas before storage, I wouldn't run it if it's been in the tank all winter. Drain the old gas and put it in a vehicle, and buy new for the boat.

If the boat was winterized, it's likely they fogged the cylinders. That usually requires new plugs the first time you run the motor.

If the hub was bad would it not gain rpm rather than lose them? He pays to have the boat taken out of the water winterized then put back in the water during the spring so I would think the boat should be ready to run when you get on it.

[Arkie John]

Marina owners are good at deflecting blame when issues arise.

I'd pull the prop (it onlly takes a few minutes) and look for anything wrapped around the shaft (trotline, etc) just to give yourself some peace of mind.

aj

[creekslick]

My step-son talked to the marina yesterday and they told him they changed the prop out to a different pitch because it was hitting the rev limiter making it drop rpms. This boat had run fine with the original prop since it was purchased new 2 summers ago. I rode on it when it was losing rpm and it was not the rev limiter doing it. He told them he wanted the old prop because the warranty did not cover the prop change.

[barn dog]

Check your fuel filter if you have one. It sounds like a gas problem not a prop. Try running some Sea Foam gas treatment through it to clean the carbs. It's avaliable at auto stores.

[speckfinder]

My step-son talked to the marina yesterday and they told him they changed the prop out to a different pitch because it was hitting the rev limiter making it drop rpms. This boat had run fine with the original prop since it was purchased new 2 summers ago. I rode on it when it was losing rpm and it was not the rev limiter doing it. He told them he wanted the old prop because the warranty did not cover the prop change.

did they change it without his consent?

[NIMROD]

Check your fuel filter if you have one. It sounds like a gas problem not a prop. Try running some Sea Foam gas treatment through it to clean the carbs. It's avaliable at auto stores.

I WOULD AVOID THE SEA FOAM. MY OUTBOARD MOTOR SPUN A BEARING ON THE CRANK AFTER USING IT. THEY RECOMMEND NOT USING ANYTHING WITH OR LIKE ALCHOL IN THIS BLENDED GAS.