This site is not affiliated with AGCO Inc., Duluth GA., Allis-Chalmers Co., Milwaukee, WI., or any surviving or related corporate entity. All trademarks remain the property of their respective owners. All information presented herein should be considered the result of an un-moderated public forum with no responsibility for its accuracy or usability assumed by the users and sponsors of this site or any corporate entity. | ||||||
The Forum | Parts and Services | Unofficial Allis Store | Tractor Shows | Serial Numbers | History |
B Revs High on it's own |
Post Reply |
Author | |
BenGiBoy
Orange Level Joined: 11 Nov 2015 Location: Ashville, NY Points: 696 |
Post Options
Thanks(0)
Posted: 29 Mar 2023 at 7:32pm |
So... Long story short, my B had to sit outside for a few months (supposed to be two weeks max, but that's a long story) and I wasn't around to start it periodically. When I got back to it there was 2 gallons of water in the oil which ran down the muffler and in through the exhaust valves which also seized the engine up. I pulled the head and got it un-stuck, pulled the oil pan and cleaned all the gunk out, as well as visual inspection of all components... (77 Hours on the new rebuild... ) Everything looked okay from the bottom, so I put that all back together and started it... It started right up and idled for a minute, but then revved up really high and I couldn't control anything with the throttle, the governor is holding the throttle on the carb as far closed as it can, so it's not something on the governor. I thought maybe it was something gunked up in the carb causing weird over-fueling or something so I took that apart, cleaned it, and re-installed with fresh fuel and a clean sediment bowl/screen. It seems to have the same problem still.... Any tips?
I did drive it a little with it revved up to see if it would change anything and it didn't, but I did notice that it had no power at all, if that helps with anything.
As I type I realized I should probably go check the valve lash... but would that do it? Thanks for any help! This is getting frustrating... Ben |
|
'39 Model B
Tractors are cheaper than girls, remember that! |
|
Sponsored Links | |
steve(ill)
Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 81440 |
Post Options
Thanks(0)
|
if it revs up , you got too much fuel... Someone else had this problem a month ago and found the throttle arm on the carb was stuck on one of the mounting bolts and would not move to LO IDLE postion..
To set the governor and carb. pull off the pin connection on the carb rod that goes forward and pins to the governor arm that runs behind the radiator, from gov to left side..... put the THROTTLE lever on the steering column to WIDE OPEN... move the gov arm and spring back and forth to see that it moves... Go to the left side of the tractor... pull the carb rod forward and back and see that it moves all the way forward, and goes back against the idle stop..... now pull the carb rod all the way FORWARD and see if the pin aligns with the governor arm behind the radiator... If not, bend the gov arm a little bit so they align..... reinstall the carb rod to the governor arm.... retest.
|
|
Like them all, but love the "B"s.
|
|
steve(ill)
Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 81440 |
Post Options
Thanks(0)
|
tractor really can not REV UP unless the throttle plate in the carburetor is OPEN... You shut down the air, and the engine speed drops...no air flow, no fuel flow ( suction).
|
|
Like them all, but love the "B"s.
|
|
TramwayGuy
Orange Level Access Joined: 19 Jan 2010 Location: Northern NY Points: 11445 |
Post Options
Thanks(0)
|
The throttle plate is probably stuck somewhere above idle. It can’t slow down any, and it can’t open up when a load is applied.
|
|
BenGiBoy
Orange Level Joined: 11 Nov 2015 Location: Ashville, NY Points: 696 |
Post Options
Thanks(0)
|
I'll check it out and see what I come up with, thanks for the suggestions!
|
|
'39 Model B
Tractors are cheaper than girls, remember that! |
|
Steve in NJ
Orange Level Access Joined: 12 Sep 2009 Location: Andover, NJ Points: 11833 |
Post Options
Thanks(0)
|
Sounds like all the rain or snow got the throttle shaft rusty. Might need a little penetrating oil on the throttle shaft...... Steve@B&B
|
|
39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife
|
|
BenGiBoy
Orange Level Joined: 11 Nov 2015 Location: Ashville, NY Points: 696 |
Post Options
Thanks(0)
|
I will try lubricating that a bit and see what happens, thanks!
|
|
'39 Model B
Tractors are cheaper than girls, remember that! |
|
BenGiBoy
Orange Level Joined: 11 Nov 2015 Location: Ashville, NY Points: 696 |
Post Options
Thanks(0)
|
Well, I finally got some time this weekend to look at it... I found that I needed to adjust the governor rod some, it was 1/4"or so out of wack... But that didn't help. The throttle rod in the carburetor is as free as it can get, opens and closes easily. The tractor is still idling really high even with the throttle plate as closed as it can get. It seemed to go faster and faster if I tightened the idle jet screw on the carburetor though, do I just have the carburetor way out of whack? What do you guys usually set yours at? (It has the Zenith carb).
Thanks! Ben |
|
'39 Model B
Tractors are cheaper than girls, remember that! |
|
steve(ill)
Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 81440 |
Post Options
Thanks(0)
|
adjust the spring loaded screws out 1.5 turns , after you screw them in to bottom...
Again, the engine can not REV UP if you have no air flow... Make sure the throttle lever goes all the way CLOSED.
|
|
Like them all, but love the "B"s.
|
|
steve(ill)
Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 81440 |
Post Options
Thanks(0)
|
faster and faster if I tightened the idle jet screw on the carburetor though
are you adjusting the JET SCREW or are you adjusting the THROTTLE STOP ( idle point).. that screw increases speed as you screw it in and open the throttle lever.
|
|
Like them all, but love the "B"s.
|
|
steve(ill)
Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 81440 |
Post Options
Thanks(0)
|
I dont know what carb you have... but "generically"... the circle on the left is the mixture screw ( to set full throttle / good running)... and the circle on the RIGHT has a screw that pushs on the throttle rod and OPENS the plate to increase idle speed.... The CHOKE is the bottom plate.
|
|
Like them all, but love the "B"s.
|
|
BenGiBoy
Orange Level Joined: 11 Nov 2015 Location: Ashville, NY Points: 696 |
Post Options
Thanks(0)
|
I'm confused as well...I've gotta have something going on. I'll try and get some pictures and maybe a video if I can get that to work on here. I was adjusting the jet screw, the idle stop screw that would hold the throttle plate open is backed off so it doesn't touch the stop at all. Ben
|
|
'39 Model B
Tractors are cheaper than girls, remember that! |
|
SteveM C/IL
Orange Level Access Joined: 12 Sep 2009 Location: Shelbyville IL Points: 8251 |
Post Options
Thanks(0)
|
Remove carb and see what the butterfly is doing. With screw backed off it should close enough to kill engine
|
|
Tbone95
Orange Level Access Joined: 31 Aug 2012 Location: Michigan Points: 11619 |
Post Options
Thanks(0)
|
Have you got a crack or bad gasket somewhere that's sucking air?
|
|
steve(ill)
Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 81440 |
Post Options
Thanks(0)
|
the air just about has to come thru the throttle plate.. If not, it will not PULL gasoline with it... and therefor not REV up.
|
|
Like them all, but love the "B"s.
|
|
youngorange2000
Silver Level Joined: 27 Mar 2019 Location: eastcentral MN Points: 310 |
Post Options
Thanks(0)
|
I had a C that would surge until I added a mising 'surge spring' from the carb to the block drain and the problem went away. I think they still sell them but they were like $40 I just made my own out of a spring I had and some wire
|
|
DrAllis
Orange Level Access Joined: 12 Sep 2009 Points: 20583 |
Post Options
Thanks(0)
|
REMOVE THE CARB AND MAKE SURE BOTH SCREWS ARE IN THE THROTTLE PLATE AND IT IS CENTERED AND IT CAN FULLY CLOSE !!! A fully closed throttle plate the engine CANNOT run !!
|
|
BenGiBoy
Orange Level Joined: 11 Nov 2015 Location: Ashville, NY Points: 696 |
Post Options
Thanks(0)
|
I got busy and didn't have a chance to look at it for a while but last weekend I decided I'd look at it and it was either going to get fixed or I'd have to get someone else to look at it if I couldn't figure it out. First step - pull carb and go through the list of suggestions that everyone left for me and I decided instead of fussing with getting the carb out with the air cleaner on I would pull the air cleaner. Low and behold I should have pulled that a long time ago. The little chamber that the air flows through after the air cleaner and where the carburetor goes too was full of gasoline... Must be someone didn't have the fuel shutoff turned off when they parked it.... Oops! Anyhow, I tried running it without the air cleaner on and it ran like it was supposed too, and with it back on it still works correctly!!
I guess I should have taken that off the first time I pulled the carb... Sigh. Anyhow, I figured that ya'll might like to hear what I found! I guess that must be the air coming through the air cleaner must have had enough fuel in it that it didn't really have to mess with anything in the carb? I'm not really sure how it still was running at such a high idle, but I guess that I don't totally care as long as it's fixed... Thanks for all the tips! Ben |
|
'39 Model B
Tractors are cheaper than girls, remember that! |
|
resurrection20
Bronze Level Joined: 14 Nov 2023 Location: Oregon Points: 78 |
Post Options
Thanks(0)
|
This saga was a 10 ticket thrill ride! I had a carb that would flood that exact passage due to an improper float position. But the tractor just backfired.
|
|
Post Reply | |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |