MILD THUNDER

I had 1:1 on my dominators, and never had an issue as far as it being overly touchy. You can adjust the accelerator pumps for the fuel shot as well.

My new quick fuel 4150s give u the linkage kits for 1:1, as well as another ratio for progression options.

MILD THUNDER

If you call the carb guys, or look thru their catalogs, and ask for tunnel ram carbs, meant for a dual 4bbl application, you find square jetting, and 1:1 linkage. The best thing about a tunnel ram, is even fuel, as well as air distribution to each cylinder.

SB

With tunnel rams, you have a throttle bore over each cylinder. You get severely screwed if you don't run 1:1 or close to it.

MT, are you doing work on his carb in the boat, or have you just helped him here/e-mail/phone, what have you ?

MILD THUNDER

Just some emails we exchanged back and forth.

I remember icdedppl was going thru this with his nickerson 850s on his blower motors. Just to get an acceptable cruise afr, he had to go to like 90 jets in primaries. (Nickerson set them up with 82s, with 86s in the primaries the thing was cruising in the high 13s). Then, to get a good wot afr, he had to pull a bunch of fuel from the secondary sides. They were progressive linkage.

My 850 holleys, didnt really have that issue. They were 80443 marine carbs, that came with 88/96 jetting, with front and rear pv's. I never measured the bleeds in them, but i wanna say the secondary bleeds were not the same as the primary. I was happy with the fuel curve on them, why it was good, i cant answer . Maybe holley knew there was a difference between a marine and street carb, other than just j tubes. Idk. Then again, i was running them in a 2x4 blower application, so really not even what they were intended for lol

SB

Reason for asking is, I know your tuning abilities, which is good. If you help on the boat and he's up for it, I'd say try it. May work out great and would be good info for the rest of us.

If not helping on/in the boat,I don't know his abilities so I don't know if would be a chance to take or not.

Anyway - been a great discussion tonight. This was fun.

Running a fever and need to take dog out so we can both take our last pee for the night. LOL. Later.

MILD THUNDER

As always, good discussions and points. Get some rest

Bill 3

When I got the boat. One engine had an old 850 Marine carb on it, the other had a converted automotive 850. The automotive 850 had 4 corner idle and it's idle characteristics were far better than the marine carb. Beyond that, both engines preformed similar, but throttles were never even, though that could be attributed to props also. I replaced the marine carb with the closest version 850 to match the converted 850 that was on the other engine. I stayed with the jetting that was in there (also what it appeared to they dyno'd with). Now with O2's I saw how dangerously lean I was in the midrange, I am trying to get that dialed in at least to be safe and then I will continue to fine tune from there.

I have learned a lot about holley carburetors, enough to know that I wish I had a pair of quick fuel 850's.

I "obviously" am no carburetor expert, far from it. I do have the ability to do about anything, what I lack is time - and sometimes patience......

fbc25el

If your carb did not come with a power valve in the front & rear and you just added the rear power valve I doubt the hole for the vacuum is drilled through. That means it isn't working.

Bill 3

Carburetor came with front and rear power valve.

fbc25el

From Holley?