OMC big bores

[JWS]

Other than measuring the bore is there any way to identify OMC big bore carbs ? Part number, etc..
I just bought a used evolution intake setup with carbs, etc... and wanted to verify the carbs were what they were asvertised as. THANKS

[STV_Keith]

I'm sure there are numbers, but the big bores are 1.625" ID at the smallest part of the throat. Also, the throttle plates will be 3-screw, not 2.

[JWS]

Thanks, JWS

[baja200merk]

the last 3 #'s in the big bores p/n is 340

[jphii]

the last 3 #'s in the big bores p/n is 340

What are you, drunk? You can't remember the PN?:rolleyes:

[baja200merk]

What are you, drunk? You can't remember the PN?:rolleyes:

never knew it, dont plan on runnin the dinosaur junk much longer:D

when u gonna put a good pic in ur sig?

[Action Dave]

never knew it, dont plan on runnin the dinosaur junk much longer:D



You're goin EFI????

[jphii]

You're goin EFI????

Aren't we all;)

[Action Dave]

Aren't we all;)

Must be nice...I'll take all that dinsaur carb crap off your hands. Don't want it cluttering up the garage you know...

[jphii]

I've got 3 different EFI front half setups, and more carb crap than you can imagine. Whattaya need?

[baja200merk]

dave you gotta see phil's garage's EFI set ups :D

[JrCRXHF]

I have a set of mid's and big bores. I am rebuild the motor with the big bores now so i am going to try and run those in the spring time. I hope i can get them to idle good enough to run chain of lakes.

[racer]

If you are going to run your 8 on the 24 you have pictured I would run mid bore carbs.

[JrCRXHF]

well the motor the mid bore carbs came off was a 86 275hp it also had a piston go bad when the other owner owned it. So those carbs have a big ??? in my mind on what is going on.


The motor i am rebuilding now had head gasket problems so i know last time it ran all the carbs worked.


Why do you say the big bore are not going to work well on the motor they came off. (that motor even had power steering that i took off)

[racer]

The 4.0 versions never came with big bores as production engines. The 86/7 3.6 had them. The big bores have poor off idle performance unless you allow the propeller to slip and tend to be lean in the mid range.

[JrCRXHF]

and all three screw bores are big bore carbs correct.

[STV_Keith]

and all three screw bores are big bore carbs correct.

Nope, I have mid bores on 3-screw throttle plates.

[lokinutz]

and all three screw bores are big bore carbs correct.

What is the six digit number on the side of your carb bodies. (not the number on the small aluminum air circuit cover).

[JrCRXHF]

I will look tonight when i go out to the pole barn.

I think we are going to over bore all the cylinders or send it out for over bore tomorrow.

I don't know who's pistons i am going to use yet.

[racer]

I would not bore the block until you know what pistons you will be using.

[JrCRXHF]

398743

on the butter fly
332250


The alumium mount is 26986


We are going to check and see the bores first because i have one with some damage and i have to see how much over we need to go to clean it up.

Then before we touch the others we will buy pistons.

[jphii]

Those are mid bores.

[kimswang]

Big Bores...