TRACTOR PARTS Allis Chalmers Case & David Brown Farmall & International Ferguson Ford & New Holland John Deere Massey Ferguson Massey Harris Minneapolis Moline Oliver & Cockshutt Kubota / Yanmar

TRACTOR MANUALS

Allis Chalmers	Case	Farmall IH	Ford 8N,9N,2N	Ford
Ferguson	John Deere	Massey Ferguson	Minn. Moline	Oliver

Oliver, Cletrac, Co-op & Cockshutt Tractors Discussion Forum

OC4 carb problem

Welcome Guest, Log in or Register

Author

D. Groff

01-22-2004 21:43:38

Report to Moderator

My '57 OC4 4 cylinder gas crawler won't start. I have spark to all plugs, I believe it's timed correct 1-2-4-3. Should the SPK mark on the fly wheel and the hot end of the rotor be on spark plug wire number one? Is spark plug number one the furthest to the outside, towards the nose of the crawler? The carb sucks in your hand if you put it over the air intake but your hand does not get wet with gas. The choke is full on and with several turn overs the plugs are still dry instead of flooded. I've taken apart the carb several times, replace the seal on the butterfly shaft, made a new gasket, tried to stop any air leaks, poked a wire down every hole and blew out with air hose, all seems clear. I can take clear tubing and put over the main jet in the center and suck up fuel or blow air bubbles through it to the gas in the bowl. The float is very free with no leaks. Why won't it start? It has two needle valves, one in the center and one on the far right end (very long, goes to bottom of bowl. What should the number of turns for these be? If all else fails, where can I get a good price on a working carb?

Thanks.

D. Groff

[Log in to Reply] [No Email]

Russ

01-24-2004 17:06:22

Report to Moderator

Re: OC4 carb problem in reply to D. Groff, 01-22-2004 21:43:38

OC-4 Dry? Use a clean and dry metal can from brake fluid (quart or pint size) and solder a copper nipple into the drilled out cap.

Run a rubber line from this nipple to a similar
fitting adapter into your OC-4 Carb. inlet.

Have a friend or helper pour gasoline into this
temporary mini-fuel supply tank.

Make sure your battery source is fully charged and have your helper hold up the can and hose
as a gravity supply. Can may be open on the bottom or a large vent opening for refill.

If your engine is producing a vacuum your spark plugs should get wet with fuel and the carb should flood out under continuous choke action.

If this works with full choke you will have to
clean out your fuel tank of rust,scale or other blockage.

Keep this fuel rig away from sparks, open flames
or other combusting sources. Good luck.

[Log in to Reply] [No Email]

D. Groff

01-24-2004 17:59:16

Report to Moderator

Re: Re: OC4 carb problem in reply to Russ, 01-24-2004 17:06:22

Thanks for everyones help. It now runs but the carb just won't adjust out. Under a load it dies, while it runs, if you put the choke on, the buterfly valve moves but it won't flood plugs and will not work for cold starting. I would like a new carb. Anyone know where to get one at a good price?

[Log in to Reply] [No Email]

Russ

01-25-2004 08:19:28

Report to Moderator

Re: Re: Re: OC4 carb problem in reply to D. Groff, 01-24-2004 17:59:16

OC Less; NOT SURE HOW YOU CAN DO IT BUT NEXT THING SHOULD BE CYLINDER COMPRESSION CHECKS
TO SEE IF EACH CYLINDER IS WITHIN 10% OF ALL OTHERS. THIS WILL PUT YOUR SPOTLIGHT ON THE CONDITION OF VALVES AND PISTON RING SETS.
IF YOUR ENGINE VACUUM IS TOO POOR OR LOW THEN
NO CARB WILL FIX THAT DEFICIENCY. SEE IF YOU
CAN GET A HELPER TO PERFORM THE ABOVE CHECKS.
GOOD LUCK. YOUR HEADLINER SHOULD READ "OC-4
IS RUNNING STRONG AND KICKING BUTT"

[Log in to Reply] [No Email]

Jim N.

01-24-2004 18:53:49

Report to Moderator

Re: Re: Re: OC4 carb problem in reply to D. Groff, 01-24-2004 17:59:16

I had a similar problem on my '58 OC-4. The problem ended up being leaky manifold gaskets. About $11. I was about to replace my carb too. The two outside cylinders were running lean and the inside two were running very rich. It didn't matter how I adjusted the carb, it wouldn't run right. I also noticed a lot of carbon fouling on the choke plate from all the backfiring. Maybe this info helps.

[Log in to Reply] [No Email]

RAB

01-24-2004 00:24:07

Report to Moderator

Re: OC4 carb problem in reply to D. Groff, 01-22-2004 21:43:38

If the plugs are perfectly dry after extended cranking while choked, then the problem is fuel related. It won't start unless fuel gets to the cylinders! When choked, my HG runs fuel out of the carb intake when hand cranking!!
I previously suggested that the carb was blocked somewhere IF fuel was getting to the carb. Undo the carb drain plug and drain the carb, then turn on the fuel and observe that the fuel runs out at a good rate. If it just dribbles, or not at all, investigate the fuel supply into the carb.
If all is well remove the carb main jet adjuster and the main jet. Clean and replace. Screw up the adjuster so it is just fully seated and then back off about 1 3/4 turns. Try to start it again.
Best of luck and regards, RAB

[Log in to Reply] [No Email]

JEFF

01-23-2004 19:34:08

Report to Moderator

Re: OC4 carb problem in reply to D. Groff, 01-22-2004 21:43:38

Is this the same crawler that ran once good enough to get onto and off a trailer? after a fresh rebuild?
If so How did it run and how did it quit? Feel your pain . Took us over a month to get dad's
running right after a fresh rebuilt. His was all starter/regulator/generator stuff though.Everytime
you tried to start it the battery was dead.

Jeff

[Log in to Reply] [No Email]

antique

01-23-2004 03:42:16

Report to Moderator

Re: OC4 carb problem in reply to D. Groff, 01-22-2004 21:43:38

Don't forget your flywheel goes around twice while your mag goes around once. Are you sure you are on number one with the SPK mark and not number 4? Take all the plugs out and put your thumb on number one plug hole, the front one and see when it comes up on compression. When the impulse trips, stop and see where your rotor is.

[Log in to Reply] [No Email]

D. Groff

01-23-2004 17:35:18

Report to Moderator

Re: Re: OC4 carb problem in reply to antique, 01-23-2004 03:42:16

I took the rotor cap off when I saw the SPK mark on the flywheel. The firing end of the rotor is pointing to the upper right hand corner of the cap where the glass window is. That should be plug wire number one, then 2-4-3 in clockwise order.

[Log in to Reply] [No Email]

[Options] [Printer Friendly] [Posting Help] [Return to Forum] [Log in to Reply]

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home | Forums

Copyright © 1997-2023 Yesterday's Tractor Co.
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy