f60 speed issue

[g32004]

Last year I bought a f60 on a 17 ft g3 boat.<br />During the breakin I had it up between 36 and 38<br />mph not sure what the rpms were reading. I never opened it up all the way last season after that.<br />This year in April I had a 10 hour service check up from the yamaha dealer I really had 15 hours on the motor. I took her out for the first time this seson last week. She now tops out at 5000 rpms and 30 mph. Why the difference do you think the dealer adjusted something. The dealer did turn the idle rpms he said they were 500 to high now set at 850 is this correct.

 

[WillyBWright]

Re: f60 speed issue

A few possiblilites...<br />First, was the motor properly winterized? Mostly I'm interested if the fuel was stabilized, then motors either run to get the stabilized gas in the carbs, or better if they were drained (or the motor run dry).<br /><br />Second, does it seem slower? Speedometers are notoriously inaccurate. Especially if you have a 65mph speedo. The closer your boat comes to the max on the speedometer, the more accurate. In other words, a 45mph speedo would be more accurate on your boat than a 65mph.<br /><br />Third, the speedometer pick-up could be partially clogged. It's either a plastic thing with a hose mounted to the transom, and many are on the leading edge of the motor's gearcase these days.<br /><br />Finally, was the loading the same? More of a load will slow you down noticabley. Related, water conditions and trim position greatly affect top end.<br /><br />Idle adjustments won't affect top end. I doubt they did anything to alter top speed. Mostly they change the fluids and check carb and cable adjustments. Other things too, but those are the main things.

 

[g32004]

Re: f60 speed issue

Thanks for your reply.<br /><br />I used the boat twice in the winter so I didn't winterize it. It stays in the garage. If the fuel is possibly the case can I add something to the fuel now. I have 3/4 of a tank.

 

[g32004]

Re: f60 speed issue

Sorry to you othe questions the load was the same or maybe 50 lb lighter at 30 mph.<br /><br />The speed read the same on the gauge as it did on my gps.

 

[rodbolt]

Re: f60 speed issue

what year model F60 ?<br />05 and up is EFI and there is no idle adjustments.

 

[g32004]

Re: f60 speed issue

2004 f60 carburated