well i was just going to put dominator 1050's on it, but the engine builder seemed very confident in pro systems. Not that I doubt them yet, the boat does idle wonderfully, has great power up till the secondaries kick, but them gets wildly lean. And I'm told the carbs are flowing over 1000

Have you checked AFR when it goes lean? Is it popping?

Are you reading the plugs correct???

You can't always go by the color of the porcelain on plugs. You have to read the color change on the base circle.

If you changed the jets from 86's to 99's and didn't see any difference in the way it ran, then something is wrong.

I to run patricks carbs on my race car and the guy knows his stuff, what he is saying does make sense to me..your flame arrester could be aiding the problem as well..just making airflow do weird things..seen it before...but I to think 1050 might be the way to go for you...but also not that hard to yank the j-tubes out and run it....

J tubes out wont make a difference.

When did this develop or did you notice it.

Its very strange you went up that many numbers and saw no diff,.... Did you check your float levels??

Had that happen one time with a PAIR of brand new carbs out of the box on the dyno went from 88s to 100 and it was still LEAN put a different carb on and 2 jet changes n we were done. I sent them back n the metering blocks were jazzed up from the factory.

Those are plenty of carb for what you are running, if you go too big you will not have enough air velocity from your engine to match the needs of the larger carb.

Id make sure your metering blocks are all ok and make sure you are using the right metering block gasket, if the wrong gasket is in there you could be blocking off needed air passages.

Mike
Roccard Marine engines
570-956-2840

hey mike, we talked a week or so ago about those engines you have for sale. If you dont mind I may give ya a call later to discuss this carb problem I'm having

we had no popping when lean. I suppose I shouldn't say nothing changed, the midrange was worse before jetting up. And now is perfect, we are using a magnifying glass to look at the base of the plugs, just no color there. I just cant help thinking something else is wrong, seems like alot of jet change to still be this lean

No prob.....gimme a call Ill be glad to help

I have personally seen two different boats where the J tubes were indeed causing a low pressure in the bowls and thusly, a lean condition. Try turning the tubes sideways out of the air flow.

auirpacker, thanks I was hoping somebody would have seen this condition before