best carb for OMC 4.3L 6V type 86-92

[coast108]

Can somebody tell me what the best Carb is for an OMC 4.3L 6V type 86-92.

New comer in boating and made a rockies mistake by bying a boat (chris craft 205BR)
from the internet because she had such nice lines.

Previous owners made a mess from the engine room and now trying to
replace part by part.

Engine now runs on a Holley with 4 barrels and my technician claims that
it is not really ideal for this engine and very difficult to tune.

Anybody know with what carb the engine was originally built with?

Thanks

Brgds, Ton

 

[Levinz11]

Re: best carb for OMC 4.3L 6V type 86-92

The 175 HP version of your motor came with a Rochester 2 barrell. OMC also offered a 205 HP (I think) that had a Holley or Quadrajet 4 barrell. The tech needs a copy of the factory service manual.

 

[mareed2k]

Re: best carb for OMC 4.3L 6V type 86-92

Ton,
I have a 91 OMC Cobra 4.3L V6 GM engine. It originally came with a Holly 2 barrel that never did run very good. I always had idle problems and other issues with the engine. Instead of rebuilding the carb and continuing to fight it I went ahead and purchased a rebuilt Rochester Quadrajet 4 Barrel Carb that had been rebuilt by a professional (they epoxied the vent that always leaks on a Quadrajet and a few other mods) and properly jetted it for OMC Cobra 4.3L. It cost me about $220 for the professionally rebuilt carb but since I put in on the engine two years ago I have not had any more issues with the engine. It purrs like a kitten. If you want information on where I bought it just let me know. You can also see a video of my engine running with a close-up of the Quadrajet here on youtube: OMC Cobra 4.3L V6 Vortec Idle at 600 RPM - YouTube

 

[Ski Bob]

Re: best carb for OMC 4.3L 6V type 86-92

I have a 1991 OMC 4.3 Cobra V-6 Chevrolet engine and I have owned it since new. It came with a 2 brl Holly and I have had the carb rebuilt twice by The Carburetor Shop in Roseville, MN . Phone 651-770-3505. This guy does racing carbs as well and knows his stuff. He has tuned my carb so my boat runs PERFECT. I would take the time to call him and he will give you top advice. He has taken the time constantly to talk to me and has ALWAYS been right on his advice and diagnostics. Good luck. Bob

 

[Ski Bob]

Re: best carb for OMC 4.3L 6V type 86-92

By the way, I had also talked to Four Winns about performance and they advised AGAINST bigger carb's because you have to exhaust what goes in!