2002 utiopia 185 boggs at 1/4 throttle

[Polcat]

I have a 2002 utopia 185 with gen 2 mercury 240efi
It would not go over 10 mph.. i did some investigating, and found a shreaded alternator belt, so i replaced that. Took it out today, and hit 1/2 throttle and it planed quick and was doing arout 32mph and 4k rpm.. i gave it more gas and it bogged right out again.. the gas is 1-1/2 years old, but i Stabilize the fuel before I put it away.. i also put in new plugs.. any ideas? Thanks

 

[biffdotorg]

A couple things here.

That's the newer generation 240 EFI, (can tell by the cover) but they are hyper sensitive to proper voltage and fuel quality.

So you have two things going against you. It must have been sitting for quite some time with that old of fuel. Best bet is drain it out, or burn it as much as you can. But also if that boat has been sitting, and then burning up a belt, your battery may not have the best charge on it. Put a charger on it and get that topped off. If need be, replace it. As these SportJets do act up without proper voltage.

I never had a meter on my electrical (as I do on my Yamaha) but my Alpine mono sub amp was more sensitive to voltage. When things dropped, it would shut down and when the sub was out, we knew we needed to go tubing and get a charge on, or head in and put a charger on. If not, the engine would do odd things.

So freshen up that fuel, and freshen up that battery to start. After that, you may want to consider spark plugs, as it is still a two-stroke. Then it's a matter of further troubleshooting if it doesn't clear up from there. Fuel separators/filter, head temp sensors etc. But start with the simple stuff. Sensors will have more cause for poor starting, rather than poor running.

Good luck!

 

[Bilmon]

Agree with everything @biffdotorg said, especially on fresh fuel. Another easy check if you have access to a fuel pressure gauge is pressure at the fuel rail, should have 41-45 pounds, engine off key on, at the valve on the vst [looks like a tire valve]. I have the same engine in a Sugar Sand.

 

[Polcat]

Thanks. Plugs are new.. and it was on a tender, so full charge.. ill try and drain the fuel and replace separator.. i also looked at trigger wire and bypassed kill switch, as those seem to be problem aread..