Power loss at high RPM/speed

[mdelleman]

Hey everyone,

Took my 1997 Pre2150wt out a few times over the last week or so to start the season. Has a Marine Power 307 with a Holley carb in it and we are having some engine "hiccups".

We are new to boats so please bear with me (-:

If cruising at a lower speed we do not have any issues but when we start increase speed to say 35-40MPH we have had power loss. I have to pop to boat back into neutral or it will stall. I can then let it idle and start on the throttle again. The engine sounds and runs very nice otherwise then this loss of power at higher RPM/speed.

We bought this boat late last year, had it checked out and it had a clean bill of health. I added Stabil to the gas when we winterized it and then filled the tank to start the season while added a can of Seafoam at the recommendation of friends who own or have owned boats.

It seems to me that this could be a fuel issue as once the boat is asking for more gas it is having issues. I am going to replace the fuel water separator today as I have read that if this is fouled it could lead to my issue and I have no idea when this was changed last.

Any thoughts or recommendations would be appreciated for this new Tige owner!

[BCRider]

Fuel pump? Sounds as if the pumps not providing enough fuel when running faster.

[TeamAllen]

I have the same year and model boat, but different engine. Gas quality or carb would be my first guess. Good suggestions form your boater friends about the fuel filter replacement. Since you don't really have any history with the boat I would start with the basic tune up stuff. Cap, rotor, and spark plugs.

[lee]

When was the last time the carb was rebuilt?

[mdelleman]

Thanks everyone for their answers.

I went and replaced the fuel water separator last night. Filled the new one with 50% gas 50% seafoam and screwed her on. Started the boat up and she purred like usual.

Poured the old fuel from the water separator filter into a gas container so I could take a look. Didn't look terrible but definitely had some gunk in there!

I still have the previous owners contact info so I decided to give him a call. He was surprised and also agreed that it sounded like a fuel issue. He recommended replacing the fuel filter as well and taking a look at the carb. He had rebuilt the carb 2 years ago and adjusted the floats. He gave me some tips on how to make sure everything is adjusted as it should be so the engine is getting enough fuel at high RPM's. Did not feel like it would be an issue with the mechanical fuel pump on this engine.

I am taking it out today as my daughter would like a ride for her birthday and will update everyone as I get it figured out!

[UNSTUCK]

Are you boating at the same elevation as the previous owner? If not, you may need to rejet for your elevation.

[mdelleman]

The fuel water seperator change seems to have done the trick. No power loss last time I took it out!

Unstuck - the boat used to live on a lake about 40m above sea level. We live in the Shuswap in BC Canada which is about 400m above sea level. Should I look at rejetting the carb?

Thanks for the help everyone.

[UNSTUCK]

I don't think you would need to. That's not much in elevation change. If it's running good now it's hard to fix what isn't broken. Having said that though, running at 35-40 mph has to be at the top end of the RPM's. Maybe you're just hitting the limiter.

[lee]

Do not think carb engines have a rev limiter.

[UNSTUCK]

Any engine can have a rev limiter. But I don't know if they were used on these or not. Can't think of a good reason not to have one.

[dj2]

If the problem returns I would move to the fuel filter and then to the fuel pump. Something is causing the fuel pressure not to keep the carb bowl full.

[UNSTUCK]

Maybe the floats just need adjustment.