Proper RPM for my Volvo Penta AQ271C?

[jberenyi]

When properly trimmed and full throttle, my boat's RPM according to the tach on my dash says 4000 RPM. Is this acceptable? I only ask because I seem to remember someone say in my travels that it should be between 4200-4500 RPM. I would love to get it up to 4500 RPM. Could the speed limiter be the cause? And where is this speed limiter?

 

[Gene70]

Re: Proper RPM for my Volvo Penta AQ271C?

you need to check the prop first. The speed limiter is not your problem.
I suggest you go to a reliable prop shop. Let them check the pitch and diameter. They can tell you what they recommend. They might have a rebuilt prop. You need a prop with a new hub in it.

 

[captmello]

Re: Proper RPM for my Volvo Penta AQ271C?

According to Volvo website, max RPM is 4600.

But I wouldn't cruise at that RPM.

you could have a Rev limiter. It has a Grey wire from the neg side of the coil and a purple from the pos side. Keep in mind there should be a Grey wire that goes to the tach as well on the neg. terminal. Follow the wires.

I'm pretty sure you can simply disconnect it to see if it makes a difference.

 

[jberenyi]

Re: Proper RPM for my Volvo Penta AQ271C?

In response to the prop question. I have two props. One OEM aluminum 15"x19p 3-blade and a Solas 4-blade 15.5"x17p in stainless. The 4-blade is on their right now. Both are definetely for this boat. I think I need to get a handheld tach and double check if the onboard tac is correct. It does act fishy every once in a while by reading higher than it should. My coil has 3 wires on each terminal. One set goes to my breakerless distributor and the other set to the speed limiter. I think the next set is the tach. Anyhow, 4000 rpm seems a littel low. I did tune the engine this week with new cap, rotor, plugs and timed her at 750 rpm @ 6 deg BTDC like it says on the engine (AQ271C). However, my Clymer manual says 650 rpm @ 8deg BTDC. We'll see what the handheld tach says.

 

[airdvr1227]

Re: Proper RPM for my Volvo Penta AQ271C?

I would imagine there would be a difference in WOT RPM's with those 2 props. I'd try it with the 3 blade and see if that works better.

 

[jberenyi]

Re: Proper RPM for my Volvo Penta AQ271C?

I would imagine there would be a difference in WOT RPM's with those 2 props. I'd try it with the 3 blade and see if that works better.

Shouldn't be much since you always lower your pitch a step down going from 3-blade to 4-blade. Dropping from 19 to 17 should account correctly for this.

 

[airdvr1227]

Re: Proper RPM for my Volvo Penta AQ271C?

Shouldn't be much since you always lower your pitch a step down going from 3-blade to 4-blade. Dropping from 19 to 17 should account correctly for this.

Easy way to verify is all...process of elimination. I'm no prop expert.

 

[jberenyi]

Re: Proper RPM for my Volvo Penta AQ271C?

Anbody know where the rev limiter is located? I have no idea where its located or what it looks like.