A friend of mine's boat...
 

Alright, I'll admit it...my Sutphen with an AQ311 Volvo Penta package (SBC) occasionally idles very high after I run into the high end of the rev range for any sustained period.

For instance, just cruising around below 4,500, no problems with idle returning to 700 rpm or so when throttle is backed down.

However, if I get on her for a bit say 5,000 to 5,200 RPM (max is 5,200 from factory), then she might "float" at 1,500 rpm when I EASE back the throttle.

This problem is intermittent, only happening occasionally, but it is severe enough that I kill the motor before shifting back into gear. Once the motor starts again, she idles just fine?

This nagging little problem has been going on for 10 years. Any ideas?

Thanks!

Re: A friend of mine's boat...
 

What kinda carb you runnin?

Re: A friend of mine's boat...
 

Stock carb. Some type of fancy Edlebrock, I think.
Manuals at the office, I'll have info tomorrow.

Re: A friend of mine's boat...
 

Found a PDF of the engine/drive package on volvo.com, but no specific info on carb. I'll have to go look-see.

http://www.volvo.com/NR/rdonlyres/00...SP_1988_en.pdf

Re: A friend of mine's boat...
 

You probably just need to play with the jetting and/or metering rods.. The adjustment screws dont have anything to do with it since they are for the idle circuit only.

Re: A friend of mine's boat...
 

I had this happen to me and what was happening was the secondaries were sticking slightly open. If you can get it to do it with the hatch open, try pushing the secondaries closed by hand, if the idle goes down when you do, you found your problem.

Re: A friend of mine's boat...
 

Thanks all.
Nova - I think I'll give that a shot before pulling off the carb. How'd you unstick the secondaries?