Upgrade Carb from 2 barrel to 4 barrel

[brodie123]

I have an inboard Mercruiser inline 6 165hp with a 2 barrel rochester.

The intake manifold is the size for a 4 barrel and there is a reduction plate to make the 2 barrel fit.

I got ahold of a 4 barrel Holley that I'd like to see if I can get to run on it.

I made an adapter to turn the 4 barrel around so the linkage is on the right side.

I have not been able to get it to idle.

I pump the gas a little and she revs way up and then immediatly dies off.

If I try to start it without giving it a little extra initial fuel, it doesn't turn over.


So my question is will the inline 6 not handle a 4 barrel or am I looking at a faulty carb?

 

[j_martin]

Re: Upgrade Carb from 2 barrel to 4 barrel

Yer on the clamp-on (outboard) thread. You should ask over on the Mercruiser thread.

 

[Maclin]

Re: Upgrade Carb from 2 barrel to 4 barrel

I have not been able to get it to idle.

I pump the gas a little and she revs way up and then immediatly dies off.

If I try to start it without giving it a little extra initial fuel, it doesn't turn over.

These are the symtpoms of a large vacuum leak, more than a missing plug somewhere. This is from the carb not sealing to the intake properly more than likely.