Volvo Penta 3.0 GLP-D SX drive, 21p 3 blade aluminum prop, won't go over 3000rpms

[whyvas]

Good day all,

I have a 2006 Stingray 185lx with a Volvo Penta 3.0 GLP-D, SX drive. New to me, unsure of previous maintenance. The boat is gutless and cannot get over 3000rpms. So far I've tried plugs, cap, rotor, fuel filter, compression is 145-140-135-140

I have been using regular gas (10% ethanol), should I switch to supreme?
I've read on the forums about exhaust flappers breaking off and restricting flow, but then someone mentioned volvo stopped using them, does my engine have one of these (2005)?
I've also read about trying to unplug the oil pressure switch and water temp switches. Is the correct procedure to unplug each one and go for a test run?
Does this motor have an engine protection mode? If so, would I get an alarm? It beeps when ignition is on but not while running.
Is it possible to scan the engine for codes? OBD2?
The trim position sender is broken, the gauge always shows the trim as being up, does the engine account for this and limit the RPMs? If so, can I trick it to think it is down?

Cheers and thanks in advance.

 

[alldodge]

:welcome: to iboats

No Volvo dude here but I can help with some of your issues.

Good day all,

I have a 2006 Stingray 185lx with a Volvo Penta 3.0 GLP-D, SX drive. New to me, unsure of previous maintenance. The boat is gutless and cannot get over 3000rpms. So far I've tried plugs, cap, rotor, fuel filter, compression is 145-140-135-140

I have been using regular gas (10% ethanol), should I switch to supreme?

No, and only if you just want to speed more for gas. You will gain nothing except less money for B-words, Beer, Boats, Babe's, etc

I've read on the forums about exhaust flappers breaking off and restricting flow, but then someone mentioned volvo stopped using them, does my engine have one of these (2005)?

Don't know for sure but they would cause more heat to build up then loss of power.

I've also read about trying to unplug the oil pressure switch and water temp switches. Is the correct procedure to unplug each one and go for a test run?
Does this motor have an engine protection mode? If so, would I get an alarm? It beeps when ignition is on but not while running.

No way no shape no how, do you unplug sensors unless only for a specific reason and only one at a time while something else is being done under test.

Is it possible to scan the engine for codes? OBD2?

Not that I am aware of, OBD2 port connectors are only found on cars, trucks, etc. You need a scan for your engine to check for codes.

The trim position sender is broken, the gauge always shows the trim as being up, does the engine account for this and limit the RPMs? If so, can I trick it to think it is down?

Cheers and thanks in advance.

Engine doesn't care where your outdrive is (trim gauge) and has no bearing on what it does or doesn't do. It's there for your reference only.

It is very possible you just have the wrong pitch prop on the boat. Has the boat ever performed properly and higher rpm's? It could be someone else liked your prop before you bought it and they swapped it for another with a higher pitch

 

[whyvas]

:welcome: to iboats

No Volvo dude here but I can help with some of your issues.

Don't know for sure but they would cause more heat to build up then loss of power.


No way no shape no how, do you unplug sensors unless only for a specific reason and only one at a time while something else is being done under test.


Not that I am aware of, OBD2 port connectors are only found on cars, trucks, etc. You need a scan for your engine to check for codes.


Engine doesn't care where your outdrive is (trim gauge) and has no bearing on what it does or doesn't do. It's there for your reference only.

It is very possible you just have the wrong pitch prop on the boat. Has the boat ever performed properly and higher rpm's? It could be someone else liked your prop before you bought it and they swapped it for another with a higher pitch

Thanks for the quick reply. For unplugging the switches/sensors, what I meant was unplug/ground each one and see if the boat performs correctly then replace whichever one isn't working correctly.

The prop is the original one that came with the boat when it was new, it was replaced shortly after for a lower pitched prop and I recently changed it back so it is like new condition. Factory spec shows 4200-4600 WOT RPM and I barely make 3000 RPM.

Any other suggestions for things to check?

 

[Fleetwin]

Is the choke plate on top of the carburetor partially closed? Air cleaner clogged?

 

[alldodge]

Thanks for the quick reply. For unplugging the switches/sensors, what I meant was unplug/ground each one and see if the boat performs correctly then replace whichever one isn't working correctly.

The prop is the original one that came with the boat when it was new, it was replaced shortly after for a lower pitched prop and I recently changed it back so it is like new condition. Factory spec shows 4200-4600 WOT RPM and I barely make 3000 RPM.

Any other suggestions for things to check?

What did the old plugs look like? Check timing and agree with Fleetwin with filters and choke.

Edit: you could pull your exhaust elbow off and look for flappers.

Double edit: according to what I have found at Volvo Europe your engine does not have flappers

 

[HalfFish5087]

Edit: you could pull your exhaust elbow off and look for flappers.

Double edit: according to what I have found at Volvo Europe your engine does not have flappers

Correct, Volvo called it quits with the flappers in '99 as they did more harm than good.

As far as gas goes, you need to check your manual and see what it calls for.

In regards to if your engine is in a protection (SLOW) mode, I do not believe that your engine has such. The beep is there to tell you that you either have no oil pressure or high temperature.

Did this condition exist with the other prop?