(800) 853-2651
SHOP NOW

M

Our Phone System is Down!

Please use the Contact us Form

We are working to resolve the issue ASAP! Thanks for your patience!

A

Anonymous-0

Well-known Member
Picked up an M at auction. We boiled and rebuilt the carb and acetoned the gas tank to clean the crud out from sitting.
Now we cant get it to run, if I hold my hand over the air horn it will suck in gas and fire off, but if I take my hand off it dies.
I put an inline filter in, clear one, when Im cranking it over no gas is moving, put my hand over the air horn and it starts, as I move my hand out to give it some air the filter emptys into the carb. The filter never does get full, ever.
My question is, is the filter screwing the carb up somehow? Or what other problem do i have with the carb for it to not run without covering the air horn
 
Inline gas filters will not work without a fuel pump so throw that thing away!! Should be some more ideas coming along shortly. Armand
 
Armand is correct, the inline filter is restrictive and designed for fuel pump use, not the micro pressure of gravity feed. Though it would seem to pass air well, it does not pass fuel much. that being said, there are fuel filters from NAPA and others that are specific to gravity systems. They are great, but the best is the sediment bowl that is OEM, along with--- By Clean Fuel Keep it Clean--
that is stamped on the old style caps.
That may still not fix your carb. Is the screen at the carb inlet clean? Is the float hanging up on the side of the bowl holding the needle closed?
Is every passage actually open to flow. These are also likely issues. Even a loose or leaky intake manifold, or one with a hole through the inside to allow exhaust into the intake is a possible contributor. Good luck, check it out and let us know. JimN
 
Glad you told us guess I should remove the ones on my tractors and lawn mowers even if they have been trouble free for 20/30 years.
 
I agree, loose the in-line gas filter. I purchased an OS 6 that I couldn't get to run, same engine as your M. After reading a post about gravity feed fuel systems and in-line filters, I removed the gas filter the previous owner had installed. Once the filter was gone the tractor fired right up.

Just make sure that fuel runs freely out of the strainer to the carb and you should be good to go with this problem.
 
Many people have success with them (especially if they were designed with them on the unit) Some are more restrictive than others. The worst seem to be those 1.5" diameter tapered plastic see through units. And not all those are alike either. THey just don't need filters when clean fuel is used in a clean tank. JimN
 
Like it says on gas gap "BUY CLEAN FUEL KEEP IT CLEAN" but sometimes this does not work when carrying fuel to field in cans. Have seen a lot of crud in carburator bowls that had gone through both sediment bowl and carburator screen.
 
We were required (by the adults in the extended family with their customary authority and steel toed shoes) to use a funnel with brass screen at every fill from cans. I don't have issues with success, just with people having problems. While working for Datsun in the early 70s, I encountered a PU with fuel problems. It was equipped with a smallish plastic filter stock. The truck had no fuel flow when towed in. (just 3000 miles on it) Turns out that a neighbor kid had poked cardboard strips down the fuel tank filler neck. The cardboard digested to the point that it was micro fibers of the same color as the filter element, but it would plug up the filter in 5 minutes. The owner changed 20 filters before deciding to have the tank rinsed out. Some people are like that. Jim
 
I have in line filers on everything I own from IH300U, H, JDA, Lawn Mower, all are gravity feed and they all run just fine.
 
If an inline filter will let fuel gravity flow, you will also see that same dirt in a carb with an inline filter. You must just be one the fortunate people if you have inline filters and no flow problem with graity feed.
Jim
 
Jim, In your extreme example the debris would have clogged the system with or without a filter. Another way to look at your example is that it was a good thing the filter was there to stop the debris before it got to the intake and engine. As I, and others, have stated in posts, inline filters have been needed and used on gravity fed systems for years with no problems and will continue to be used successfully. I think this M problem is going to be resolved with carb or compression fixes unrelated to inline filters. On this one we agree to disagree.
 
first thing I would do it take the line loose at the carb and see if you have good fuel flow. If you do then try opening up the drail on the bottem of the carb to see if there is fuel there. If you dont then you have a problem with your float. If you dont have fuel comeing out the line at the carb then work your way back to the tank checking to see if anything is pluged. On my M I have something in the tank that is pluging. I am going to have to drain tank and see what it is. My experence with those inline filter has not been good so I am not a fan of them. These tractors have ran for more years then I have been around with out them. The key is just keeping things clean. Its hard to do with this crap fuel we get now days.
 
Fuel flow is the obviouse number one check whether its inline or in the carb. You may also have an intake leak. Do the smoke test and see if you are drawing in air around the intake flanges or carb mount.
 
ill take the filter out today and put in a piece of tubing and see what happens. I dont think the float is stuck, carb has a fresh rebuild, (last tuesday) and when I opened the pitcock on the sediment bowl gas flowed to the carb, then stopped, thinking the float worked(?) Thats when i noticed the filter didnt fill full and left about a 1/2 inch air bubble at the top.
Only reason I stuck the filter on was to help get the little pieces of gunk left from cleaning the tank out. The guy had left gas in it for 2 years and it was full of crap.
 
They make inline gas filters for gravity fed fuel systems. I have one on my garden tractor
that's only been changed once in 37 years. If removing your inline filter lets the engine start you probably have one that's to be used with a fuel pump. Hal
 
Buying and using the CORRECT in line filter MAY help, but those old carbs were not that finicky. Any dirt that would pass the screen in the sediment bowl and the screen before the float, MOST times would not cause severe running problems. The symptoms that were described point to the inline filter being the problem.
 
If it stopped, then something is stopping the flow, whether its the filter, crap in the line, or the float not opening all the way. Doesnt matter if you rebuilt the crb or not, if the float is catching the sides of the carb, or binding on the pin, then it wont flow. HAve you taken the cap off to see what happens? Could have plugged up the vent hole from sitting.
 
Bull (that is the translation of el toro isn't it, LOL),
A PROPERly sized filter will work. The fuel bowl on your garden tractor is alot smaller than the M's and the passages are a lot smaller, a much shorter distance from tank to carb, etc. Just because the line sizes are the same doesn't mean it will work. Micron size of filter media has a big effect on flow. JD9295 should first see if the fuel runs thru the line after the filter and compare that to before the filter. May also check the vent on the cap.
 
After what you have done I would look to the carb first. The main jet goes through a fiber packing and just one little speck of that packing will stop the main jet cold that would be my first guess. Second is the float and that will most likely stick open instead of closed. The float must work freely so what I do is put the carb bowl on loosely and mount it to the manifold hook up the gas line and turn on the fuel. If the bowl overfills the gas will run out the air intake side of the carb. if it doesn't open the bowl will not fill so no gas will run out the drain. If you leave the bowl loose on the carb y0ou can gently move it around till the float is working. OI know that sounds complicated but if you try it you will see how well it works. after you get the float working tighten up the screws you can get to and take the carb off to tighten the remaining screws.
I bet the problem is the main jet.
 
You MAY be right. I had an H with the same symptoms. I changed the carb gasket and it ran fine. Like I said, we agree to disagree but it doesnt matter as long as he gets his M to running.
 
JD, none of my inline filters ever fill full. There is always a little air in the top. Just the nature of the beast.
 
if you need to run an inline filter, stop at napa and pick up either a 3031 or 3032 in line filter, one is for 5-16's fule line, the other is for 3-8's line, they are full flow and will work with a gravity flow fuel system. prolly around 6-8 dollars for the filter.
 
By-Pass
When working on electrical problems I always have my jumper wires handy to easily by-pass suspected trouble spots. Have em up to 7ft long. (you never know). When working on fuel system problems, same thing, a one pt plastic bottle with hose attached, saves a lot of guess work. I'm strictly talking tractors and small engines, be careful.
Bob S.
 
Bob S, I like your ideas, also your caution to be careful. It reminded me of the story of the B-29 "Kee Bird" that they tried to repair and fly 0ut of Greenland after setting for years. It was destroyed by fire after it got to bouncing on a taxi test run and the can of gas they had hanging over the Aux. power unit ignited. Just a little piece of trivia I thought I would throw out.


Gene
 
You must log in or register to reply here.

Similar threads

B
MH 44 Won't keep running.
Replies
19
Views
598
stevieb49829
stevieb49829
W
Farmall M Carb.
Replies
4
Views
448
WiJay
W
T
Stumped on M Tuning
Replies
14
Views
678
560Dennis
560Dennis
S
Farmall M Fuel Flow
2
Replies
24
Views
1K
DR. EVIL
D
R
1949 8N wont start, has electronic ignition, new plugs, very white bright spark
2
Replies
23
Views
1K
Fixingfarmer
Fixingfarmer
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.

Copyright © 1997-2024 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

Back
Top