Ford NAA-Trouble Running

Gonefishn

New User
During the fall I was having trouble with the Ford sputtering while idling and under load. I recently installed a rebuild kit for the MS carb. I figured my trouble could have been coming form the ethanol gas now available. I installed the carb on the tractor and have been trying to get it adjusted. I set the idle mix needle at 1 turn out and the pwr jet at 1 and a half turns out. Turned over a couple of times and started to run. I adjusted the idle mix needle to get a smoother run and stopped at about .5 turns out from bottom. During this adjustment the tractor would cut off but crank on the first try. I started using the throttle handle to increase the gas flow and opened the pwr jet needle to about 2 full turns out. The tractor will run great for a minute or two and then I will hear a change in the rhythm of the engine. The engine is not running as smooth. Shortly after the engine will quit as you have switched it off. On the first try the engine will start and run for another minute or longer and quit.

I checked the gas flow out of the bottom of the carb just as the engine quit. The flow was good. I checked the elbow filter at the carb, removed the gas line from carb and sediment bowl and cleaned. I also checked the gas flow from the sediment bowl valve and the flow seems to be good. There is not a noticeable change in flow whether the gas cap is on or removed.

After putting all back together the engine cranked on the second try. Ran about the same. I increased the flow on the pwr jet about 1/8 of a turn. The engine then seemed to be better able to handle an increase using the throttle handle. I then noticed that if the engine started to sputter and shut down I could work the throttle handle and find the sweet spot and the engine would level off and run for a minute or two.

It appears to me that I have adequate gas flow to the carb. I have checked wiring connections, points and they appear to be good. I am confused as to why the engine stops and will then crank immediately on the first turn of the key.
 
still sound slike gas flow to me.

open drain at bottom of the carb and set a LARGE GLASS JAR DOWN THERE AND JUST LET HER PEE.

give it a good minute.. see what happens.

the fact that she stats back up after stall means it probably wasn't a loss of sparkies.. unless you have an ignition switch with loose guts that kills spark from the key jiggling in it.. etc.
 
Gonefishin'.........you write......." The tractor will run great for a minute or two and then I will hear a change in the rhythm of the engine. The engine is not running as smooth. Shortly after the engine will quit as you have switched it off. On the first try the engine will start and run for another minute or longer and quit".........typical BAD CONDENSER ........do I haffta tell you to replace yer condenser??? Condensers can be BAD right outta the box.

Yer gittin' close on yer carb adjustment. Set the down-pointing mainjet to 2-turns and LEAVEIT!!!
Adjust the side-pointing idlemix for FASTEST idle, NOT SMOOTHEST idle. Understand the difference??? Remember, the side-pointing idlemix is BASSACKWARD; out fer lean, IN fer ENRICH. Yer idlemix should end up about 1/4-turn. Remember to re-adjust the behind the carb idlespeed to less than 500-rpms. It usually takes me 3-trys before I'm satisfied with my carb adjust. ........Dell, yer self-appointed sparkie-meister
 
I sat a container below the carb and let about a quart run from the plug, about a minute. There was no change whether the gas cap was on or off.

When I rebuilt the carb I put in a new float. There was not much adjustment needed. I have it set at about 1/4 inch. I used a 14 drill bit for spacing. I was told that the float may need to be set even closer. It does act as though it is losing fuel. I do not want to touch the float without maybe changing the condenser first.
 
might as well change the tire too!

shotgun parts guessing and changing will just empty your pockets.

your call.


condensors have 2 failure modes.. open and short.

open condensors allow points to burn. once that happens.. you won't restart untill you repalce or dress the points.

not yer problem.

shorted condensors kill spark by shorting the points. Shorted condensors are probably the rarest form of failure.. and generally it is a thermal issue... thermal issues are not immediate onset.. nor immediate dissipation. If you have a stall and you can restart 5 seconds later.. it's extremely unlikely that your condensor shorted and then fast healed.

Alsys east to check points opening and closing, externally, with a test lamp hooekd to the feedthru post on the dizzy.. blinking lamp means points are opening and closing and condensor is NOT shorted.

ps.. check them muffler bearings while you are at it.

:(
 
Hey GoneFishin,
It's funny that you posted this, cause my 641 is doing the SAME EXACT thing! I can usually keep mine running a LITTLE bit longer by fiddling with the choke but it'll only run a bit longer before it dies, but it fires right up again!
 
If it helps, as I said in my previous post, my 641 had the same exact symptoms that you posted and I thought a simply tune-up (didn't replace points/condenser as they looked brand new from the previous owner [email protected] +/- so I left em alone) would solve the problem-it did not.
However, last night my 641 exhibited the same-above mentioned issue after the tune-up and then died and would not restart. So today I threw a test light on the dizzy post and cranked the tractor (expecting to see the test light flash as the points opened/closed) but the test light did not light-up once. So I pulled the points/condenser out, and sure enough the points were fried and the condenser was no good. I threw in a new set of points (gapped at .025, I always keep a couple sets handy) and condenser and she runs like a top now!
 
Good to hear. I have a new set of points and a condenser. I plan to try these shortly. I will let you know. Thanks
 
Thanks, I replaced the condenser and the Ford started on the second try from a cold start and has run great since. I adjusted the carb as Dell recommended. Pulled a set of bottom plows and the gang disc with her yesterday. Cranked and run great all day. Thanks again !
 

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