Here it is, all torn apart again!

It idles fine, and will run slowly, at a snail's pace. Under a load, or when trying to get more than a couple miles per hour out of it, nothing. The engine will die right out if you keep holding the throttle open - pop, bang! I've had a similar problem with it before, not so extreme, but more about that in a minute. The fuel pump seemed to be doing nothing. So, here's what you get for $40 to rebuild the pump:

It's hard to see from this picture, but the plastic diaphragm (which is the "pulse" diaphragm) was warped and stretched so bad that it couldn't possibly have been pulsing much, if at all. It was resting almost tight against the pulse fitting opening. I replaced the three gaskets and two diaphragms (40 bucks) and now the pump actually pumps fuel:

But, it runs no different! So, back to square one, and back to the problem I had before with it. The air box and cover are warped, broken, and otherwise going to hell. The bolts that hold the cover broke out of the box. The engine was acting in a similar way after that happened. I drilled holes in the box and replaced the missing bolts with bolts all the way through from under the lip. That held the cover down pretty good and made it run perfectly once again:

Now the cover is warped even further, along with the sides of the box. Plus, the bolts I replaced have begun to pull clear through the box lip. One corner was completely loose. It really looked like it was still sealing better than when I had the problem before, but maybe not. At least I'm hoping that's the problem! Especially since the air box and cover are $120. I'll know by the weekend if a new box will cure it.

Otherwise, I don't know what it could be. There's a possibility that it could be the diaphragm in the top of the carb (it's a stupid vacuum carb like junk Fords used to use - that's a bad sign right there). I was told those cost 50 bucks, but I have since looked up the price myself and they are actually $76! What a crock. If the air box doesn't fix it, then it may not get fixed. It's so old and has so many miles on it that it's not really worth putting a lot into it anymore. It's certainly paid for itself and been one excellent machine over the years, but it might be time to let it go. No better time than now anyway. I've already been planning to use other methods to plow snow, I can use my old truck or the older ATV to haul firewood with, and with ATV clubs that like to make money and fight more than they like to ride.................