Rough / Racing engine

[Aces_Over_Kings]

Hi all,

2010 Speedster 150, just put it in the water for the first time this season. 45 hours on the clock.

The engine is running rough, at idle it sounds kind of like a motorcycle if that makes sense, and underway it's constantly racing/revving. The RPMs are bouncing around quite a bit. I can buzz around, get up on plane, and it starts reliably and quickly. But the power delivery is very uneven and fluctuating. It'll be at 4000, race up to 5300 (with the associated boost in power) and then back to 4000.

Last use was probably last August, and it was winterized in late November, stored full of fuel (stabilized). I also just replaced the battery with an Optima BlueTop D34M.

Could this be fuel that's gone bad? Too little or too much stabilizer?

Could it be the new battery?

Any thoughts or ideas welcome. Nothing like Day 1 issues during a week of vacation in remote Maine, miles from anywhere. Ugh.

Thanks in advance for any ideas!
-- Josh

 

[4x15mph]

I don't know anything about the speedster but can you try a new fuel filter and new plugs? It sounds like you might not have access to much with where you are.

 

[Aces_Over_Kings]

Thanks 4x15mph. I don't have spares on hand, but I'll add those to the list of things to look into.

There are some pretty sizable lakes around so there may actually be a seadoo place nearby. I'm having to hold my phone at a funny angle to get my one dot of 3G cell service, so until I can contact a seadoo service place, I may just burn some fuel in the boat and then mix in some fresh stuff to see if it improves.

I appreciate the ideas!

 

[Aces_Over_Kings]

Just wanted to close-out this thread. It seems to be fuel related. I bought a bottle of fuel additive (Phaze-Out) at NAPA auto parts, and after running around for a while to burn off some fuel, it seems to be running much more smoothly.

I'll burn off the old fuel, pour some fresh stuff in, maybe with some sea-foam, and I think it'll be all set.

Seems like someone forgot the Stabil last fall. Guess maybe I should add some myself this fall even though it's part of the winterization service I pay for.

 

[itsdgm]

Glad you got it figured out @Aces_Over_Kings Dont feel bad though. I used stabil over the winter and somehow my fuel went bad too. I ended up having to drain the tank. So sounds like you caught it just in time