Volvo Penta AQ230 Revs in Neutral but limited power under load

[PghBoatGuy]

Hello iBoats!

I have a 1992 Volvo Penta AQ230. Originally, the boat had trouble starting. After replacing the distributor cap and rotor, it idles nicely. We went ahead and adjusted the dwell and it is in spec 62 +\- 3 as listed in the service manual.

After taking the boat out on the water yesterday, it had very limited power when shifted into forward gear. I could push the throttle all the way forward, the RPMs won’t advance past 1300. This is not the case in neutral, where the engine revs up and down normally.

I should not it is difficult to tell exactly where it is RPM wise as the boats tachometer is also jumpy and will occasionally go all the way to 7,000 then back down again. Could this mean anything? Or is it more likely to be just a bad tachometer?

In the process of reinstalling the distributor cap we accidentally cracked the housing. We took care to install the spark plug leads one by one from the old cap. With this said, the boat was at a mechanic shop before we installed the distributor cap and rotor. They were the ones who diagnosed it. Is it possible the wires are swapped? Could that cause this sort of issue?

And what about a spun prop? It would just seem strange as the boat won’t even rev up when put in forward.

Thank you!

 

[captmello]

did you adjust your timing after setting the dwell?
I would do a compression test on the motor.
doubt it's the prop, but put a spare on to compare.if your timing and compression are good.
the firing order is easy to check.

 

[Tristador]

Definitely replace the cracked cap.
Do you notice it misfiring under load?

 

[captmello]

forgot to mention, the Rach can have odd effects on the motor when bad. I would disconnect the taxh at the coil. it's usually a grey wire. then use a good shop tach to check the rpms. reving on neutral means nothing. also after rereading a spun prop would allow the rpms to jump, not hold them down.

 

[Scott Danforth]

a 92 should not need dwell adjusted (points) as there should have been electronic ignition in 92

 

[PghBoatGuy]

Hello,

There is definitely no electronic ignition. It has a distributor with points, condenser, rotor, etc. Maybe the year is wrong. It is on a boat from 92.

We did not set the timing after adjusting the dwell. Got a timing light and am going to try that next. Will also try disconnecting tachometer and see what happens. Will also see about trying a spare prop.

Thank you for your insight