www.iFourWinns.com

I have a problem with my engine at wot..
I will start with explaining that i change spark plugs ngk,volvo penta wires,distributor cap,rotor,all filters ,new ss prop,all bellows,everything in drive is ok,add smaller type filter on fuel line which is not full with fuel when engine runs maybe thats the problem,or maybe carburetor or tank clogged but before i start with checking everything i would like too see if anyone here have some advise..
Engine start and idle ok
Boat planes ok
boat cruise ok
The problem is that somewhere between 4000-4600 rpms engine cuts out and rpms go down to 2000-3000 and then will again start going up..
Thanks...

_________________
2006 FOUR WINNS H180
Volvo 3.0

Are you saying the engine surges once you get up to the higher RPMs? Or does it sound more like it is droppping a cylinder or 2? If it surging I would look first for a fuel problem. Could be slight debris on the fuel pickup screen or something clogged in the carb fuel filter. As far as the inline filter I am not a fan on sterndrive engines, I prefer the screw on water separating filter type.

_________________
Brian Borchik
The Winds of Cold Springs Harbor Marina
Baldwinsville, NY

Thanks for reply
No it is not sounding like cylinder problem..
I also changed the carb filter..
I will start with locating the problem from the fuel tank to fuel pump to carb

_________________
2006 FOUR WINNS H180
Volvo 3.0

not too familiar with the I/O's but on car engines (which is my understanding is all they are) i would start with checking all your vac hoses. Better yet, just replace them all, there shouldn't be too many. It's amazing how a small air leak can cause a big hiccup.

Did you try running the boat with the fuel tank cap a little loose? That will show if there is a fuel tank vent problem.

_________________
2008 210SS 6.2L DTS Bravo 1 Now featuring MercMonitor w/SmartTow

That is typical sign of fuel starvation on carbureted engine… As others say You have some kind of blockage in your fuel system . Blockage in Vent rube would cause fuel to not flow well to fuel bowl as well…

_________________

08 H260 VP 8.1Gi DP.....Previous
2013 Crownline E6 Merc 8.2MAG BIIIX, DTS/SC