My Ford 4000 3 cyl running very rough

bach939

New User
I got a Ford 4000 3 cyl that runs very rough. I had New Holland rebuild thr carb, but still have the same problem. When I installed the rebuilt carb, I couldn'get it to start. In doing some testing, I found I have no spark. Put on a new coil, but the same and rechecked the points. What I did discouver was jumping the + side of the coil to the + of the batt it started, but runs really rough and at time backfires. Took the jumper off and It started to settle down and ran pretty good for a while then back to the rough running thing. For sure, I have to do the same jumper to the coil to get it started. I pulled the three plugs and they were fairly black which tells me it's running rich. It runs better at low rpm's, but as I advance the throttle, it starts running really rough and backfires occasionally. Is there a possibility the vacuum advance is not working and why do I need to jumper the coil?

HELP!
 
Bad ignition switch could cause the problem with having to hot wire it. Back fire many times means running to lean or out of timing and timing can be caused by the points set wrong or the advancement in the distributor not working as it should or your timing just flat out needs to be adjusted a bit. Black plugs if oily is oil fouled. If sooty then gas fouled. If gas fouled your air cleaner could also need to be serviced and be clogged up
 
First of all check your spark. You must have a bright bluish white spark that will jump at least 5/16". Short or yellowish spark will not do.
Buy your points at Napa - Blue Streak or Standard brands. NOT from TSC which have notorious failure rates.
Take a 1/2" copper fitting brush (see photo)and one at a time pull each wire in the harness and clean them - both sides of the connection. The mantra here is "clean bright and tight".
Once you get good spark go on to fuel.
First of all you mentioned you are restoring this tractor. So you will want to go through the fuel system to insure you are getting good fuel flow to the carb.
There are fuel filters in the following locations.
1) in the fuel tap in the bottom of the tank.
2) on top of the fuel pump on the timing cover behind the fan.
3) in the fuel bowl just behind the carburator.
4) sometimes, but not always in the brass fitting where the fuel line goes into the carb.
I know you said it is running rich so fuel is not likely your problem but these filters don't often get the required attention so now is the time to do it.
Lastly, and I hate to tell you this because you likely dropped a bunch of dough on the carb rebuild, Those Holley carbs are NOT well thought of here.
I won't even mess with one anymore.
I just toss them and buy a new Zenith from this site.
Zenith will make you break your piggy bank to buy one but will make a man out of that tractor.
One more thing: It takes three things to make a gasser run. Fuel, air and spark at the right time.
I am assuming you have good airflow to the carb ie, Clean air filters.

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nnalert the Zenith Carb
 
(quoted from post at 15:35:56 04/25/15) Bad ignition switch could cause the problem with having to hot wire it. Back fire many times means running to lean or out of timing and timing can be caused by the points set wrong or the advancement in the distributor not working as it should or your timing just flat out needs to be adjusted a bit. Black plugs if oily is oil fouled. If sooty then gas fouled. If gas fouled your air cleaner could also need to be serviced and be clogged up

Thanks for your responce. I'm thinking it's the ingnition switch also. Put one in aboout 2 years ago. The strange thing is, when i turn the switch to on position, I get a 12 v reading on the coil, but it won't start unless I jumper it. Anyway, I'll put in a new switch. The plugs are dry sooty and I can see no intake restriction and ran with air filter out. I'm thinking you're right about the distributor advancement may not be working. Any ideas how to check that?
 
Volt reading with out a load can read what it should but when loaded it is not what is should be. That is the problem with meter it can read what you should see but under a load not be as it should be
 
(reply to post at 22:34:36 04/25/15)

Pretty strange. One day it ran perfict and the next day the starting and rough running problem started. Just like a switch was flipped.
 

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