Ok we have 3 Suzuki 9.9 four strokes here at the property I work for. We use them for our fishing rigs on the lake. We have been having problems with the studdering and not spitting water. I think the main reason is b/c they are governed and they don't get to blow off the carbon at higher rpms. They run 2500 rpms max . Because it is a no wake lake. I was thinking about running seafoam in it to burn it off I know people have used that on 2 strokes. I just don't wanna blow these motors up.

Any help would be much appreciated!

Seaform is used in all my small engines all the time. ATV, chain saw, power washer, lawn mower, weedeater, 2-stroke and 4 stroke outboards.

It won't help with the water pump though, you should get those serviced before you ruin the motors.

not spitting water sounds more of a serious issue. When was the last time impellers were changed? Tune up?

about 1.5yr ago they barely get run is the bad part :'( they are very seasonal. Do you run the seafoam in the gas tank or what. Just apply the recommended  amount directly into the gas tank and always leave it in?

I'm not sure I see the connection between being governed and not spitting water. I'd be looking at clogged intakes and/or impeller problems.

I see you are from SC. I fished Santee-Cooper in SC for a week or so once a year for many years and I know the locals had issues keeping their wanter intakes clear.

Good luck

I have a 40 HP Suzuki. There are many times during the season I have to pull the small nozzle on the water return and clean it out. It seems the Suzuki's have a smaller hole and it clogs easily.

I run a Johnson in the same waters and never have the problem.

Pull the small black nozzle and clean it. That may solve your water return problem.

BTW That return is only an indicator to let you know the water pump is working. The cooling water runs out the prop hub.

GamecOcks5, mix one ounce of Seafoam per one gallon of fuel.

I keep a 5 gal container of gas treated all the time to fill the tanks of each piece of equipment. You can add it directly to your boat gas tank also in that ratio.