John Deere 420 runs rough

[DougH420]

Hey guys. I am new to the forum. I just recently got my grandfathers 1958 JD 420W with a Bush Hog 305 mower and a back blade. It also has a 45 loader that is still at my grandmas house, we ran out of room on the trailer.

It had been sitting in a barn for about 3-4 years without running. We drained the old fuel, replaced the plugs, rotor, cap, coil and condenser. We didn't replace the points yet since the ones Steiner send didn't fit, but did clean the existing points.

After all this it started up and we ran it at half throttle for about 10 mins and it ran normally.

About a week later I started it up and drove it around the yard and ran fine, parked it in the front yard and put it down to the lowest idle and the started to sputter and eventually died. I have attached a short video of how it is acting. In this video it is running with no oil in the air cleaner canister (I just cleaned it out and didn't have any new oil to put in) however this is typical of the problem. The exhaust manifold has a few holes in it. We have a new one ready to put on but the old is going to have to be cut off, one of the bolts is rounded over and rusted on.

Any advise on where I should start?

http://www.youtube.com/watch?v=tatMYdf0HOU

 

[nlastovi]

I'd guess that the passages in the carb are probably a little gummed up. Probably fastest and easiest to remove the carb and clean out every last hole with some fine wire best as you can. A dip in the carb cleaner bucket (not the spray stuff) before and after won't hurt a bit either.

Then check the timing and valve clearance for fun.

 

[Mike M]

That 45 loader was made to fit on those,but broke most of them in half that tried it. Those tractors were not good for loaders.
Possible the condenser went bad too.

 

[Anonymous-0]

The neighbors say that my 420s sounds like its only running on two cylinders.

 

[DougH420]

The carb was going to be my first spot to clean, I just wasn't sure if there was anything else that I might have overlooked.

It sounds like I have a hit and miss engine in there...

 

[M-MAN]

Still need to change those points. NAPA will have them but ask for the better set. You should also change the manifold. If there's holes on the outside there's a good chance there's holes between the exhaust runners and the intake runners.

 

[bollweevil]

I use Borg Warner A40H Points. Available at most parts stores.

 

[DougH420]

Well yesterday I got a new (used) tire put on and I changed the points. Fired it up and it ran without hesitation. Not only did it run good but now the 3 point hitch started working.

So one can conclude by logic that changing the points made it run better then changing the tire fixed the hitch....

Thanks for the advise guys.