Rpms will not get over 2500 full throttle-AQ125B/270

[punttheball]

I have an AQ125B/270 volvo-penta. The motor will rev to over 5000 rpms when in neutral....When I shift into forward, it will take off but will never get over 2500 rpms or 10 mph. The motor runs smooth during this time but will not accelerate. It does backfire every once in while. I just figured that was because to much fuel was getting to the carb and is not getting used. What is my problem

 

[captmello]

Re: Rpms will not get over 2500 full throttle-AQ125B/270

Sounds like it could be starving for fuel or timing could be off, timing belt perhaps.

What's the maintenence history? Did it work better before, last year...?

 

[punttheball]

Re: Rpms will not get over 2500 full throttle-AQ125B/270

Have talked with someone who believes that it may be a rubber boot or hub that is in the outdrive that has gone bad. Does anyone know the correct name for this part and how expensive or hard it is to replace?

Please be kind...... just new to all of this.

 

[gene8084]

Re: Rpms will not get over 2500 full throttle-AQ125B/270

It's called a bellows. There is a drive and exhaust bellows. If you lift the OD you can examine the belows for age and cracking.

But, I'm having a hard time relating your problem to the need to replace your bellows. Don't get me wrong, if they're old definitely replace them, but don't expect that to correct the RPM problem.

If the bellows failed and flooded you may have a number of parts that need attention. (i.e. universal joints, etc.)​

 

[Bigfishpa]

Re: Rpms will not get over 2500 full throttle-AQ125B/270

I just went threw this this year with my volvo engine.Turned out to be the mechanical advance in the distributor. With a timing light check timing at idle then rev engine up you should get about 38 degrees advance if not it will be your distributor.They want 1200 for new one I got a used one for 400

 

[captmello]

Re: Rpms will not get over 2500 full throttle-AQ125B/270

Have talked with someone who believes that it may be a rubber boot or hub that is in the outdrive that has gone bad. Does anyone know the correct name for this part and how expensive or hard it is to replace?

Please be kind...... just new to all of this.

the bellows is not expensive to buy, it's expensive to pay someone to do it since the ujoints are probably bad and perhaps the intermediate bearings.

Are you mechanically inclined? Many of us have done that work and can help if you have the ability.

Your Low RPM issue could be many things. You have to go through it one step at a time.

Have a look at this link. Are you able to check through these?

http://forums.iboats.com/showthread.php?t=295070