Miss on 1 and 4

Do you have the plugs wires set for 1 2 4 3 firing order?

Is it 1243 the right way around the cap going one way its 1243 going the wrong way makes it 1342 btdt

It seems odd that those two plugs don't change engine note when the wires are pulled off yet the tractor still runs well with a slight miss. Pull two or three of and the tractor behind missing profusely, stuttering and on the brink of dying out. Plug a good one back in and take off 1 or 4 and there is no change. All the spark plugs are getting good spark that will jump a large gap and all the plugs make spark. I have a tester with a new plug an old plug and a window to watch the spark and they all make decent spark but not as good as the new plug. Compression is good as well so that's not the cause either. We are going to change plugs and dyno the tractor to ensure all 4 cylinders are contributing as the miss seems to go away under load in road gear with the brakes on. I will also note that the timing doesn't line up with the mark on the flywheel compared to where it runs. The mark on the flywheel is too retarded. The timing marks are Lined up as well. The only thing is it changed to a 45 crank and used the 45 cam and gear in the wd block. The cam was also ground to 175 specs by Barry's cams I believe in minnesota

They are set to 18 thousands of an inch warm per the cam card. I also had barry do my cam

Any idea what timing should be? We ran it until it labored then back until it loaded up and then put it in the middle. Have noticed that 1 and 4 are across each other on the distributor. Swapped cap and rotor with no change. Is it possible it's in the carb? I would think carb would effect all the cylinders though

Maybe it is the distributer lobes are worn, or the bearings on the shaft...

"the miss seems to go away under load in road gear with the brakes on."
Getting enough fuel in it? Carb to small? using the WD manifold? got an air leak in the manifold gaskets?
 Identical compression PSI on all cylinders?


Or the camshaft is not timed right? Or possibly a degree change got made while grinding camshaft?

How many HP is it dynoing at?

Maybe just for giggles, swap the wires on the cap from hole one to hole four and four wire to one hole. and see what happens.

Have you used a tester for checking continuity in the spark plug wires?
 Solid core wire or carbon core?

old farmer wrote: What are your valves set at? My cam done by Barry to 175 spec is to have valve clearance set 18 thousands per there spec sheet with the cam.

Does yours have a bit more lopw to it now after the regrind

It seems to be, everything moves freely and snaps back

I believe I'd check the rockers for wear plus the shaft. They can be worn at the shaft and also where the rockers contact the valve. You might try opening up the valve clearance a few thousands on 1&4 and see if that makes any difference. Do you have a WD or a WD-45 head? Don't know whether if it would make any difference.