holley carbs

[floridacrakr0470]

ive got a 500 cfm two barrel on a 220 gpu. what size jets are yall runnin? tryin to "supertune my boat for summer ridin season. thanks

 

[Larry]

I've got my dad's gpu set up with 76 main jets. This is a high compression dual mag motor.

Larry

 

[floridacrakr0470]

is that a two or four barrel? ive got dual mags, but compression is stock. id really like waterthunders input on this one.

 

[Larry]

It has a 500 2 barrel on it. Most people I know run between 70 to 78 mains in these carbs.

Larry

 

[Waterthunder]

On a stock 220GPU a .076 main jets work pretty good year round. I use to run a .078 in the winter and a .074 in the summer. With out a doubt I prefered the 500CFM Holley 2 barrell the best on my 220GPU. I ran a 450CFM, 650CFM and a 500CFM four barrel and a 350CFM and 500CFM two barrell. The 500CFM 2 barrell just out performed everything else. The 450CFM had the best fuel economy but not as much power and response. When I switched ignition systems and opened up my plug gap my fuel economy improved the most and with a 500CFM 2 barrell she ran great.

 

[floridacrakr0470]

waterthunder, cause im stupid when it comes to carbs. can you explain the whole summer winter thing. was there a noticeable amount of power between the two jet sizes? also, what plugs and gap were you runnin? i run a delco c76 now, seems to work good, but dont have anything to compare to.