8.1's low WOT rpm's

[susanandlance]

Question on 2007 8.1 Horizons, port max rpm 3800, starboard almost 4000, bottom is dirty from fresh water growth but would spark plugs also cause this lack of rpm's? 4200-4600 is operating band for these engines. Thoughts?

 

[paulswagelock]

Sure. The 8.1 can run on 7 cylinders and sound smooth but drop 1000 rpm at WOT.

Those motors eat plugs and wires.

 

[superwa]

Just check that is not the gauges. Those can get wacky at times. You may need to read things at the engines.

 

[susanandlance]

Thanks guys, Broker is having service dept look at it tomorrow, I'm not there until next week, made an offer on the boat pending sea trial and survey. I had an 8.1 HO 425 in my 2005 Fountain and never experienced plug and wires problem but I'm all for learning.

 

[Pony Racer]

cool fuel module are probably the issue.. your injectors are also probably plugged up with the paint..
just spend 3500 fixing it..

 

[techmitch]

Thanks guys, Broker is having service dept look at it tomorrow, I'm not there until next week, made an offer on the boat pending sea trial and survey. I had an 8.1 HO 425 in my 2005 Fountain and never experienced plug and wires problem but I'm all for learning.

Interested in what they found?

 

[susanandlance]

cool fuel module are probably the issue.. your injectors are also probably plugged up with the paint..
just spend 3500 fixing it..

That's exactly what it was Pony Racer