Engine won't reach operating rpm. 83 Volvo penta aq125

[Mrabernathy]

Hey guys, another issue... I got my 1983 bayliner caprie w the Volvo penta aq125 & Volvo penta 270 inboard/ out drive. And I took it out this weekend, started out great running like a new one, then it got sluggish 30 mins later. Temp was fine. It would not reach full throttle in forward. It would go about half way or less throttle and that's all. In neutral it will rev full throttle just fine. Reverse is bad, the prop jumps clean out of the water and detaches itself from the locking bar. I found it does not want to latch very well when tilt is all the way down.. Took it home, and running on muffs off the hose, everything is good! And I found if I work that spring and locking mechanism with my hand before I lower my trim it locks better. Well took it back out Sunday, started off sluggish but it got up to full rpm, made sure my trim locked down fully lowered. Then I stopped to throw a tube out and it wouldn't get bad up to speed, checked to see if my trim was locked in place and it was. Put it in reverse and the prop jumped out of the water again. And detached from the locking bar. I have had the boat now 2 weeks. I replaced the timing belt and got it top dead center, but have not hit it with the timing gun. New plugs. It had an electric fuel pump and filter seems fine. It had me running that first day perfect anyway. The outdrive has been apart at sometime by the previous owner, it all looks new, new boots and rubbers. The propeller is not perfect, but not terrible. The boat still fires right up, ideals in neutral fine for a while and it will cut off. But I figure that's carb issues. It will idle for 5 mins straight though. Could the problem be with the outdrive not locking like it should fully lowered? Or do you think I just need to get it timed in with a timing gun. I didn't think timing was my issue since I was great that first day for about 30 mins, and it starts right up. What do you think guys?

 

[jerryjerry05]

The lock down isn't the problem.
That's a problem but not the one your asking about.
That sounds like the points or the dist isn't set right?
Timing?
In N almost any sick or diseased motor can rev to the limit.

Under load? Could be fuel flow? Coil getting hot? Timing?
You really need to use a timing light.
Setting it by "ear" only works under the tree.
Worked with a guy who said I don't need a timing light.
He worked on a new boat and part of the check was to set the timing and dwell and adjust the carbs.

The owner called the same day said the boat was running like crap.
I got sent out as the owner said he didn't want the "know it all" mechanic back out on his boat.
Turns out the "ear" was off by about 20d. Could have done some real damage.

 

[Mrabernathy]

Okay thanks a lot I'll start by getting my timing right, and all of that. I suspected that may have been the issue, but I wasn't sure beings I was running great one day and then it just went to ****. I guess that's how it goes thought