B missing under load

Matt E.

Member
Recently got the motor back together but didn't do too much to the lower end. I did grind the valves/seats. Rebuilt the carb and the mag had to be put back together, PO had a coil on it. Put points/condenser in it. I did not replace the wires, rotor or cap.

I was out last weekend to get the antifreeze right in it and I also topped off the rearend oil. Went for a drive with her just to warm it up good and get some seat time. Drove a couple miles over to my nephew's farm and then back.

Going up a hill would cause the motor to miss. Once up on top, it would smooth out. It would also miss when taking off in 4th but smooth out.

The motor starts super easy and idles great. Is this a timing issue? Or do I have the wrong plugs in it? Champion D-16s right now if I remember right. Spark appears to be fine on all also. Tractor hasn't really been run more than a a couple hours since we got it back together. I don't think it is a valve train issue, we adjusted/fine tuned that several times to make sure it was right before buttoning it up.

I feel like I don't have the mag set right, maybe just a little retarded but let me know what you think.
 
Well I would first throw the champs away and get a set of auto lites in the same heat range as a D-21 champ and see if that helps. Also does choking it hurt or help?? If it helps it is running to lean if it hurts then could be to rich but either way champ are no longer a very good plug for this crap gas we now have
 
Nope, choking it doesn't help at all. What # Autolite plugs are recommended guys? I know I've seen it in another thread but can't get the search to find the right one.
 
(quoted from post at 10:04:13 11/26/12) Nope, choking it doesn't help at all. What # Autolite plugs are recommended guys? I know I've seen it in another thread but can't get the search to find the right one.

Autolite 3116 is the only plug to use with a magneto ignition. You also want to use solid copper core plug wires.
 
thanks Rustyfarmall, I must not have been holding my mouth right because I ran another search and found the 3116 as the recommended plug from the old posts.

I'll get a set of plugs and see what happens. If it doesn't help, I'll reset the mag timing again. The book says to lean the mag towards the block, bring #1 to TDC on compression stroke and then rotate the mag out until it snaps. Lock it down. Then it is timed right. Dad put the mag on the tractor but I'm not sure he timed it that way.
 
Your mag is ok or it wouldnt start they are set to fire on TDC then advance when running. If it starts like you say its ok. You could pull the plugs and look if they are clean.
 
I know you did the valves BUT, you might want to take the valve cover off and make sure everything is working properly. Run it with the cover off. Its easy to do.
When my A ran like you describe, I had a couple push rods that fell off because the rocker arm assembly wasnt bolted down properly.
 
I use ACs in some and Champs and dont have any trouble also use Ethanol. Go on tractor rides mow yard plow garden and so forth even park them in the shed till spring and they will start just like when i stopped them in the fall dont see where the problems are must be due to your state regulations on gas or something.
 

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