carb question aq271c w/ 290dp

[sean169211]

hi guys wondering if i bought the right carb for my boat first off i have a 1988 sunrunner 22ft cuddy with an aq271c engine with 290 dp. The carb i bought is a holley p/n 80309 with rebuild kit 703-45 installed i have it on my boat and it seems that my boat doesnt wanna burn all the gas this big carb is letting in. I know its a 715cfm and from my understanding this is much to big for a 350 motor with no modifications. i had a similar post but i didnt know what carb it was but i found my receipt .. thanks in advance !

 

[Maclin]

Re: carb question aq271c w/ 290dp

The correct carb will be a dual fuel inlet vacuum secondary model with primary and secondary metering blocks but no idle circuit provisions or power valve circuit on the secondary. The 715cfm flow rating sounds about right. That may seem high but it is vacuum secondary controlled so it does not necessarily use all of it. The 715cfm rating is what it can flow up to. The carb should have a 2.5hg or 3.5hg power valve, and 78-80 jets in the primaries. It is setup richer than a typical off the shelf automotive carb.

You had mentioned in previous posts that you had a double pumper. Those are mechanical secondary carbs and would not be correct.

 

[Maclin]

Re: carb question aq271c w/ 290dp

That post was from memory, I just found the specs I was looking for and the carb you have there is correct as long as it has the J-shaped overflow vents that aim into the carb throat.



LIST # CFM STOCK JETTING POWER VALVE TYPE
80309 715 (F)72,(R)80,90 2.5 4150


The front jets are a slightly richer 72, and the rear jets are staggered, one is an 80 and one is a 90. The power valve is the 2.5hg. All of that makes this carb work on that engine.