Volvo Sp outdrive what gives?

[Cumberland67]

I have a 93 Welcraft with a 4.3 l engine and a Volvo Penta Sp outdrive.
Yesterday we were on the lake cruising when the engine started to losing power suddenly , I pulled the throttle back and turned back toward the dock .The boat would not reach plane again.
With the outdrive engaged the engine begins to stall ,much like a clogged jet in the carb (around 1500 rpm) but with the outdrive not engaged the engine revs up fine by manually operating the carb (through 4000 rpm).
What I am having trouble understanding is the engine was taching 3200 rpm normal cruising rpm , but the output wasn't enough to bring the boat to plane.The outdrive makes no strange noises. The oil is fine in the outdrive , the level as well as the color (no water or metal shavings)
What could stall the engine , and at the same time cause the output to be slowed to the point the boat will not plane?

 

[Don S]

Re: Volvo Sp outdrive what gives?

What could stall the engine , and at the same time cause the output to be slowed to the point the boat will not plane?

I doubt you have drive problems, sounds more like fuel or spark problems.
Is the spark weak yellow coming from the coil, or bright blue/white and jumping a 1/2" gap.
Plugged up fuel lines, tank pickup plugged, fuel tank vent plugged, water in the fuel, failed fuel pump, water/dirt in the carb, all sorts of fuel problems will cause your problems.
Remove the water seperaring fuel filter and pour the contents into a clear container an check for water.

 

[Cumberland67]

Re: Volvo Sp outdrive what gives?

The water seperator was fine ,the spark may be a bit yellow , but is jumping well over a 1/2" .I did have to clean the inside of the carb last year due to it having white rust I went ahead and replaced the fuel pump hoses ,fittings and filter.
I will check through those again , and being the coil seems to be the original Im going to go replace it just eliminate the possibility of heat break down.
Thank you for input and thoughts , I will let you know what I find.