Rough running Bigfoot

I have an '02 60 hp Bigfoot EFI on my pontoon. It was tuned last year and had new plugs, wires, impeller, fuel pump and fuel filter. I have put about 60 hrs. on it since. It has been running great until last weekend. It starts without a problem and runs well at low speed but at higher speeds (above 4000rpm) it seems rough, like it's missing a cylinder. I got off the lake without a problem, pisser is working well and restarted without a problem. Rains were coming so I had no time to check it out. I'm going back to the boat next weekend and would like some suggestions as to what to check. I'll be checking the plugs and wires. I know little about fuel injection. Ideas and suggestions anyone?
Sorry, no manual YET, but it's high on my list.

Re: Rough running Bigfoot

Anyone?

Re: Rough running Bigfoot

bump

Re: Rough running Bigfoot

Did you ever figure out what was wrong with your motor? I have a 60 hp Mercury tiller that is having similar issuses. It runs fine at low speeds and even at higher speeds for a little bit but then starts shaking badly. If I back the throttle down then it stops shaking and runs fine. It revs up fine in idle and no trouble in reverse. I didn't have this problem a few months ago. It is a river work boat so it get knocked around a bit from sand bars and other debris. Any suggestions?

Re: Rough running Bigfoot

they bog out because the fuel injector is clogged

Re: Rough running Bigfoot

stuckinthehole said:

Did you ever figure out what was wrong with your motor? I have a 60 hp Mercury tiller that is having similar issuses. It runs fine at low speeds and even at higher speeds for a little bit but then starts shaking badly. If I back the throttle down then it stops shaking and runs fine. It revs up fine in idle and no trouble in reverse. I didn't have this problem a few months ago. It is a river work boat so it get knocked around a bit from sand bars and other debris. Any suggestions?

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I never had a chance to fix the problem. Someone stole the motor shortly after pulling the boat from the water. Someone else's problem now. Replaced it with the same model.

Re: Rough running Bigfoot

Jeep Man said:

I never had a chance to fix the problem. Someone stole the motor shortly after pulling the boat from the water. Someone else's problem now. Replaced it with the same model.

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Ouch, that really sucks there are a lot of low life's out there, but someday they will get theirs.