VP 4.3 L GI 2000 wot problem, sx drive.

[stu man do]

At my wits end, having issues with one engine not reaching wot. Best it will do is 3800 rpms under load, trimmed down. The other engine will do 4400 rpms. I have done a turn up(cap, rotor, plugs), had codes read by marina mechanic, only code was low oil switch. Would this cause an rpm loss? They got the code to clear by wiggling the wire to sensor/switch.

I have added sea foam, injector cleaner, cleaned air filter, replaced gas filter. It is like I do not have the last 1/4 throttle on the one side. The engine scan proved spark advance is right, so anything I am missing?

I checked the TBI and the butterfly is wide open, measured the throttle linkage and same as other engine.

Went through Don's list, no prop changes, clean hull, etc.
I plan to have the fuel pump pressure tested this week.
The engine idles fine, and sounds perfect.

If there was an exhaust blockage (this engine does not have the flapper) where would it be, outdrive? I am asking because I did have an impeller go bad, never overheated, just lost a few fins. I have found most of them in the thermostat housing.
2000 VP PEFS TBI SX-M Drive 2660 Regal
Thanks

 

[Don S]

Re: VP 4.3 L GI 2000 wot problem, sx drive.

Best it will do is 3800 rpms under load, trimmed down.

Trim it up some, when all the down the boat will be plowing and will loose rpm. Trim up till you get best speed and rpm. When you trim too high, the rpm will go up and the speed will go down. When trimmed too low, the rpm and speed will be low.

 

[stu man do]

Re: VP 4.3 L GI 2000 wot problem, sx drive.

thanks for the quick reply Don. I do not think it is the trim. The other engine is trimmed all the way down and still reaches at least 4100- 4400 rpms. The rpms on the problem engine do not climb as fast as the other and max's out at 3000 rpms until it gets up, then goes to the 3800 rpms. Once on plan I can trim and over trim and get the rpms over the 3800 rpms. It seems like the engine does not have the same torque as the other? I have been told that the SX drives are pretty much bullet proof, no issues with bearings, or boots, so I have ruled out a problem with it being the drive for now. engines have only 230 hours. If I had a bad high pressure side fuel pump, would it still allow me to over trim and get higher RPMS?

 

[Don S]

Re: VP 4.3 L GI 2000 wot problem, sx drive.

Do you have the full model number or better yet the serial number for your engine?
http://www.volvopentastore.com/mall/template/store/volvopenta/help.html

 

[stu man do]

Re: VP 4.3 L GI 2000 wot problem, sx drive.

Port: 4012040369 Starboard: 4012040363 engines

Port: 4202016025 Starboard: 4202016025 Drives

 

[stu man do]

Re: VP 4.3 L GI 2000 wot problem, possible new symptoms?

Re: VP 4.3 L GI 2000 wot problem, possible new symptoms?

noticed alternator getting very hot, any idea why this is doing this? Also noticed a sheen of gas around boat after running for a short time while idling.