Cant go over 2500 rpm

Tdore1076

Recruit
Joined
Jul 26, 2019
Messages
1
I have a 1987 28ft bayliner cuddy cabin with a 560 Volvo penta sterndrive. It runs great no miss in motor. Reves up and sounds good in neutral. When i go out it runs fine till sbout1/2 throttle then just bogs and wont go over 2500 rpm. Had the carb rebuilt still same problem. I was told it may be the prop. Any ideas?
 

kenny nunez

Captain
Joined
Jun 20, 2017
Messages
3,056
How long has this problem been happening? Did it start all at once? In regards to the last suggestion on the “stickies” referring to throttle movement.
Start the engine and let it idle until it is warmed up. Turn it off and remove the flame arrestor. Push the throttle to wide open and see if you can gently push open the large air valve on the secondary side. There should be some slight spring tension felt. While holding it open is the lower secondary also full open?
When the boat is in the water and the the throttle is full open and the RPMs are at 2500 does the RPMs seem to increase slightly while pulling back on the throttle for a few seconds?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Bogging after 2500 sounds like a fuel delivery problem?
The new fuel, Ethanol can melt the inside of the fuel lines.
You system still OEM?? Usually by now the OEM filter's been removed or bypassed.
Check the tank vent. Bugs can get in and block off the air.

Also check the springs under the dist. cap, they might be rusted and not allowing the dist. to advance??


Not saying there isn't? Never heard of a 560 ? 570A yes and a 501 but no 560.
 
Last edited:

Insomnium

Seaman
Joined
Apr 7, 2017
Messages
54
Mine idled and ran great in idle until I pushed it hardin gear. It would t barely go over 2500 also. I pulled the plugs and the gaps were all over the place. Replaced them with new and properly gaped plugs, adjusted idle mixture, and timed engine and it runs sweet now.

Get a vacuum gauge and get some readings, you might need to adjust your carb, your timing could be off, acc pump on cab wasn't serviced , etc. Pull the plugs and check the gaps at least
 
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