Outboard issue, seeking advice

[big guy]

I have a '94 25 hp Merc, has been a great engine and still is for the most part. However, the last couple of seasons it has run poorly at low idle, used to troll really well, but I use my Minn Kota exclusively now as it runs so poorly at low rpm. At high rpm and running full out, it runs like a dream, pushes the boat 27 mph with just me in it, never hesitates, no issues. At about a 1/4 throttle and lower, especially lowest, trying to troll with it, it sounds like it's missing, will kick a little to the port side pretty much constantly, very annoying.

 

Last year I had it in and the guy took it a part and changed the gaskets, it ran well after that for about 3 trips and it started all over again.

 

Was wondering if anyone had an idea what might be wrong with it, as I was thinking of tackling it over the winter myself.

 

Any help would be greatly appreciated. Thanks

[Salmonidstalker]

When was the last time your spark plugs were replaced?

[davey buoy]

Maybe a dose of seafoam is in order,only hearing great reports for two strokers.Idle seemed to be a issue before adding.Maybe give it a try.It is a two stroke I take it?.

[Old Man]

My guess is a plugged pilot jet in the carb. Sounds like a good carb cleaning is in order.

[big guy]

Thanks for the replies. Yes, plugs are changed regularly, I take care of the engine, winterize it, change the lower end oil, plugs, only run high test in it, Stabil in every tank etc. The plugged pilot jet sounds interesting, I will endeavour to look that up on the Net to see how to fix it.

[Wagoneer]

Most of the time all you need to do (not sure how mechanically inclined you are) is remove the carb, remove all the jets and let it sit in carb cleaner over night. Check the float height, if it's level, bolt her up and usually it's all it takes. Carbs are finicky things.

 

Could also just be as simple as the weather changing and you need to adjust your idle fuel mix screw. They're also temperature sensitive. Carbs are genius inventions, but there are a ton of reasons why everything is fuel injected now

[Fish Farmer]

Seafoam was the mechanic that fixed my 4 wheeler.

[jimmer]

I think checking the jets and float pins is a good idea. I was having trouble with my 25 Yamaha one fall with the idle, so I took it apart and found a tiny piece of rubber blocking the float pin resulting in too much gas. However, try running seafoam through it before you take it apart. I am also confused that the person replacing the gaskets didn't do a thorough cleaning job while he had the carbs off. Maybe he didn't install the gaskets properly????