1961 International 3/4 ton 4X4

[Jer]

I have a 1961 International 3/4 ton 4X4 with 266V8. It is used as a plow truck(for snow). It started acting up. When I put any resistance on it, it starts to miss and sputter and almost quit. I put new wires, coil, dis.cap, points, resistor, and plugs on it.What could be wrong? any ideas/

[edkajo]

Dirty fuel filter?

[jeff campbell]

is the dizzy shaft nice an tight? or can you wiggle it back an forth?if it's got more than 1/16" of play in it,it will mess w/points. did you set the points at .016? jeff

[Jer]

By "dizzy shaft" do you mean the distributor?

[jeff campbell]

yes

[cklskypilot]

Could be a couple of things
1- fuel problem- check fuel filter, check fuel flow at carb, check carb jet, acc. pump, may need to rebuild carb but that is later after you check other possable problems.

2- check dist- points, all wires include coil wire, check dist plate, check primary and second wires, check vac avance and double check to make sure that dist lead wire is not shorting out as advance plate moves, there is a lot more to check but this will give you a good look at what you have and a good chance that one of these are the problem. other things that could cause this problem. Bad coil, weak or broken valve springs, bad head gasket, bad valve, bad lifters. low oil presure. and more but check step 1 and 2 you should find the problem there. Best of luck. Chuck

[MarkOb]

I think everything that needs to be said has been said.

So I will say a little bit more.

If it starts and idles fine but starts to give problems when any load is put on it my first thought would be in the fuel system.

You don't mention where you are located but if you are in WA or OR you most likely have had to use ethanol blended gas. If you have used ethanol blended gas then I would say your problem is most definitely fuel related.

The ethanol plays havoc on the fuel system. One of the worst things ethanol blended fuel does is free up all of the crust and corruption that has been sitting idle on the bottom of your tank. Once all of that crust and corruption is free floating it is then pumped through your fuel system grunging up everything along the way. At the least you will need new fuel filters. At the worst a new fuel pump, new lines, and rebuild the carb.

Good luck.

[sotis]

10 bucks says 2 wires are mixed up in the firing order

[stevesfixit]

if it does'nt have hard seats on the exhaust valves in the heads you could have burned out a valve seat because you're running unleaded fuel through it i've had it happen to me years ago when they changed to unleaded from leaded