Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

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

Discussion Forum
:

LAPPING CARB.

Welcome Guest, Log in or Register
Author 
MAC

06-16-1999 11:20:31




Report to Moderator

As many of the old timers on the board may remember, a while back someone explained that by taking the carb apart and sanding with a fine paper both mating halves, the engine would run much better and smoother. Well I finally got around to trying it. You can not believe the differance it made. The engine not only runs smoother,it has more h.p. and you can idle it down to a point of somewhere in the 70rpm range. I am amazed and just wanted to pass this info along once again. It can be a tricky procedure because it is necessary to remove the float bracket. If anyone wants further advice feel free to write. And whoever it was that made that first posting on this subject I THANK YOU!!

[Log in to Reply]   [No Email]
bg

06-17-1999 21:37:31




Report to Moderator
 Re: LAPPING CARB. in reply to MAC, 06-16-1999 11:20:31  
I don't doubt that the procedure works. I'll probably try it someday. But, I want to know why? If the two faces were metal-to-metal I could understand it. But you have this big old gunky gasket in there....



[Log in to Reply]  [No Email]
EricG.NH

06-18-1999 14:08:03




Report to Moderator
 Re: Re: LAPPING CARB. in reply to bg, 06-17-1999 21:37:31  
bg,
Here's a SWAG at why. The gasket seals and helps the surfaces to mate. It also helps to separate those parts of the carb that have gas from those that have air. In particular the idle fuel circuit. Fuel must flow up from the lower half, through the gasket, and the idle jet which is in the upper half. From there it's mixed with incoming air and on to the throat. This fuel circuit is located in roughly the middle of the carb, with the venturi right next to it. Any leakage of air into the idle path or vice-versa would cause problems. So my guess is that lapping the halfs helps the gasket to "seal and separate"
the fuel things from the air things, probably in the idle fuel circuit.
Eric

[Log in to Reply]  [No Email]
ZANE

06-16-1999 18:58:30




Report to Moderator
 Re: LAPPING CARB. in reply to MAC, 06-16-1999 11:20:31  
I think it may have been my post that you read. I have done this to the marvel carb many times to get the enging to idle right.
I learned the art of lapping while in reciprocating engine school in the AF in 55 and we had to use it extensively lapping rocker box covers on the Pratt and Whitney engines. They were prone to warp and leak a lot. The B29 engines of 3350 cubic inches carried 80 gallons of oil so it could leak a lot and still have enough oil to fly for 10 or more hours with some left over most of the time.

[Log in to Reply]  [No Email]
MAC

06-17-1999 06:05:49




Report to Moderator
 Re: Re: LAPPING CARB. in reply to ZANE, 06-16-1999 18:58:30  
Well Zane, i certainly do appreciate your advice. It really worked much better than I can even convey to others on the board. Thanks again.



[Log in to Reply]  [No Email]
Tommy(MO)

06-17-1999 07:01:22




Report to Moderator
 Re: Re: Re: LAPPING CARB. in reply to MAC, 06-17-1999 06:05:49  
How 'bout an explanation of the lapping process used on the carb? What did you fellas use to do it?



[Log in to Reply]  [No Email]
MAC / Hey Zane pls read.

06-17-1999 08:30:05




Report to Moderator
 Re: Re: Re: Re: LAPPING CARB. in reply to Tommy(MO), 06-17-1999 07:01:22  
Tommy, I've sent you what knowledge I have via email. I feel my details are rather lengthy to post on B.B. Perhaps Zane will repost his original info or tell us where to find the original post. His is much more accurate than the process I used on my kitchen table. How about it Zane?



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


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