How many CC carb. should I have.

[Rich Novak]

1972 225 omc sterndrive.
What size carb should be on it.
I just bought a rebuilt 650 cc Q jet.
The mechanic says it is to big only turned adj. Screw out 1/4 turn. Now can't get full throttle.

 

[gm280]

You can actually determine mathematically how big a carb needs to be for most any engine. If you know the Cube Inch displacement and the absolute top RPMs it can handle, you can do the math and determine the biggest CFM carb it can use. Problem is most folks think, wrongly, that the bigger the Carb the better. But that leads too many times to an engine that bogs instead of having a snappy throttle response through the entire RPM range. Rule of thumb, it is always better to have too small carb then too big of a carb... I don't think a 225 could seriously use a 650 CFM carb of any manufacture. JMHO!

 

[Bondo]

Ayuh,.... What carb was on it when ya started,..?? What happened to that carb,..??

The Q-jet is a variable cfm carb, 'n has been run on tiny, to huge motors, with different tunin' of course,.....

 

[strikemike]

We have also a 1973 225 V8 and we have a 4BBL Quadrajet. Thats "original".