Yesterday's Tractor Co.
Shop Now View Cart
   Allis Chalmers Case Farmall IH Ford 9N,2N,8N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   Traditional YT Forum ViewClassic View   RegisterRegister 
 ProfileProfile    Log inLog in 

Unsteady engine rpms Ford 641


 
Post new topic    
View previous topic :: View next topic  
Author Message
MNGB
Long Time User


Joined: 02 Jan 2005
Posts: 1384
Location: WC MN

Report to Moderator

PostPosted: Thu Aug 06, 2009 1:26 pm    Post subject: Unsteady engine rpms Ford 641 Reply to specific post Reply with quote

Hi all, I just rebuilt the carb on my 641 and after removing and reinstall about 6 times I finally got the needle & seat to stop leaking and flooding into tha aircleaner hose. Before I started the tractor run fine but the needle & seat was leaking and the jet adjustments were off. So I installed the carb set the idle jet to one turn out and the main jet to 1.25 turns out (Marvel carb) started the engine made some fine tuning adjustments to the idle and got it running good warmed engine up to 170*F fine tuned the main jet. Engine is running good but it will not idle down past 700 r's checked the idle stop screw and it is off the stop no way for it to go lower in checking found that the throttle rod was not pushing on the governor arm at idle so I went to adjust that and found the jam nut loose, adjusted the rod to where it pushed the carb rod to the idle stop. Adjusted the idle and all seems good went out and test drove the tractor and now at high rpm's the engine slows a couple hundred rpms then speeds up and slows speeds up and slows never did this before. Any Ideas?
 
Back to top
View user's profile
old
Tractor Guru


Joined: 12 Mar 2000
Posts: 77934
Location: Lake of the Ozarks area of MO

Report to Moderator

PostPosted: Thu Aug 06, 2009 2:50 pm    Post subject: Re: Unsteady engine rpms Ford 641 Reply to specific post Reply with quote

You need to set your main jet a bit more most likely running to lean which will cause that type of problem
 
Back to top
View user's profile
MNGB
Long Time User


Joined: 02 Jan 2005
Posts: 1384
Location: WC MN

Report to Moderator

PostPosted: Thu Aug 06, 2009 4:30 pm    Post subject: Re: Unsteady engine rpms Ford 641 Reply to specific post Reply with quote

Thanks OLD, tomorrow I'm going to enrich it some, by the way the rpm's vary about 50 to 75 now that I got the tach working again.
Now another question I can not get this engine to idle below about 600 r's setting the idle screw lower and it just idles down and dies turn the screw in less than 1/8th of a turn and r's are up to 650/700 is this normal or what?
 


Last edited by MNGB on Thu Aug 06, 2009 4:34 pm; edited 1 time in total
Back to top
View user's profile
old
Tractor Guru


Joined: 12 Mar 2000
Posts: 77934
Location: Lake of the Ozarks area of MO

Report to Moderator

PostPosted: Thu Aug 06, 2009 8:42 pm    Post subject: Re: Unsteady engine rpms Ford 641 Reply to specific post Reply with quote

These carbs are simple but they do not like ANY dirt of rust in them. I have learned that soaking them for just a few hours is not enough and have started soaking them 3 or 4 day then takeing a dremal tool and cleaning them out. Last one I did was on an IH 300U and the tractor starts so fast now you can not get your hand off the key fast enough 90% of the time
 
Back to top
View user's profile
MNGB
Long Time User


Joined: 02 Jan 2005
Posts: 1384
Location: WC MN

Report to Moderator

PostPosted: Fri Aug 07, 2009 2:48 pm    Post subject: Re: Unsteady engine rpms Ford 641 Reply to specific post Reply with quote

Hi OLD, thankyou thankyou, a 1/4 turn richer and it runs perfect just like before. I got so involved in the throttle rod adjustments that I got tunnel vision.
 


Last edited by MNGB on Fri Aug 07, 2009 2:49 pm; edited 1 time in total
Back to top
View user's profile
Display posts from previous:   
Post new topic    Yesterday's Tractors Forum Index -> Ford All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  

TRACTOR PARTS TRACTOR MANUALS
Fast Shipping!  Most of our stocked parts ship within 24 hours (M-Th). Expedited shipping available, just call! Most prices for parts and manuals are below our competitors. Compare our super low shipping rates! We have the parts you need to repair your tractor. We are a company you can trust and have generous return policies. Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ About Us ]

YT Home  |  Forums

Modern View Forum powered by phpBB © 2001, 2005 phpBB Group

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