scarabrick

My father in law has a 24' chapprell (sp) full cabin with a sbc and volvo penta duo prop. It's totally stock and i'm wondering what should be the timing for the altitude he runs it at (6000ft)? also it has a holley carb and the bowls have never been off so I don't know what the jets are but i'm sure they are stock. What should I change the jets to for the altitude? ( the carbs a little vaccum secondary.) All the numbers I got off the engine are as follows volvo penta 570 570A/ps 4100130470 868389 . the boat was set up to run here in las wages like 2000 ft altitude I only get about 4100-4200 rpm's and thats it. I don't live near the boat so I'll have to check everything in a month when I go back up there. Thanks for the insite
Rick

Baja232

maybe this will help a little.

I live in SF bay area and brought my boat to lake Tahoe (6,000 ft) last summer. I have a carburated 7.4 mercruiser on my Baja 232.

I called many people in Tahoe to ask what to do when I go to high altitude. The consensus was to not mess around with the carb, but to just prop down a size or two.

So I normally have a 23P prop, and i went and bought a used 19P prop for the week.

The bottom line was the prop was too low pitch, and I should have stayed with the 23p and made NO adjustments of any kind.

The boat ran the same up there as it does at home, and I would suggest that he try it first and see if his doesn't run the same also.

Everyone said not to mess with the carb unless thats where the boat will stay permanently.