Problems with flat 4

CoupeBoy

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I've got this old 9n (well maybe it's a 2n) 1942/43 vintage. Since I picked it up, I've performed the following updates.

Head machined straight (it was shaped like a banana)
Helicoil the headbolt hole that allowed the head to warp, the PO used a length of ready rod as a headbolt. :roll:
New Rings/rods/mains, I had the pistons/rods hot tanked.
Replaced the oil pump with one from a different motor, the old one had 'self clearanced' it's back cover.
New coil
new points
new plugs

After reassembly it didn't start. It has compression but it's weak and I don't have a compression tester that works, apparently I broke 1 and the other one is 'stuck', so I don't have numbers. With the plugs out you can feel it build compression (these aren't high compression motors) and with the carb off it will suck your hand onto the carb opening.

The distributor can only go on one way, there is a slotted groove in the cam that is offset to one side. The distributor mounts to the front of the motor and the drive from the dist has a 'key' on it that is also offset and will only mate to the cam shaft in one location. I tried both, you can't even get the bolts anywhere close to tight when it's 180° off.

I have a manual at home so after several failed attempts to start, I pulled the timing cover and verified the timing marks. I know it gets spark you can see it when you have all 4 plugs out but still hooked up to the wires.

The original carb has had several repairs to it in the past and is best listed as 'parts' but the working carb with the same throat opening size off of my CoOp E4 bolts right on. So I know I have spark and fuel, but the best I've ever gotten is an intermittent pop or backfire. I've tried it this with a brand new 6v battery and no resistor wire, I've tried it with a 12v batt and a GM resistor block inline to the coil. The only difference has been that the motor spins faster when I use a 12v. There is no generator and no lights in the dash, AND the original resistor is burned out, so aside from the ignition there is no other 6v only parts to worry about.

I know there has to be something that I'm missing, maybe my manual at home is incorrect about the crank to cam timing or it might be wrong about the firing order (quadruple checked by me, and double checked by my brother) but that doesn't mean our source of information is correct.

This tractor has been taking up space in my shop for almost 2years now. And I've never had so many new parts correctly replaced and things not work out. Granted I don't go out and work on this thing everyday, heck it's lucky if I work on it once every 6 months. It bugs me that there is some little something on this tractor preventing it from running and I just don't know what to do with it next.

Valve Job? But the valves close all the way and it builds vacuum, and they rotate like they are supposed to, I can spin them by hand.

I should probably buy or borrow a compression gauge to get real numbers and re-re-re check the cam timing.

Anybody got any suggestions?
-ron
 
Plug wires on the wrong terminals of the distributor cap and not firing the right cylinders at TDC? Pull all the plugs, ground the 2,3, and 4 wires well away from the head and carb. Bring the number one piston to TDC on compression. Rock the engine back and forth and see if the number one wire makes a spark. If not find the wire that is sparking and route it to the number one cylinder. If nervous about turning it with the fan belt, put it in top gear and rock the tractor back and forth. Then route the remaining wires to the correct plugs in firing order. Good luck
 
I can give that a try, I pulled the head though because I was thinking that a valve might be stuck open, plus with a flathead it's a tad more difficult to find TDC by shoving something in the hole since it is off to the side. On the upside I can still perform your test but I will just have to watch for the intake valve to close then the piston to come up. And I'm not afraid of turning any engine by the fan belt. But this motor doesn't have an alternator or belt on it right now, I'll use a wrench on the front of the balancer instead, or grab the belt and throw it over the balancer pulley. I wonder if the rings aren't seated and I have lower then normal compression?
Topic: '50 8N STILL wont start... recommends putting some ATF in the cylinders for a day or two then trying again.

And even when it's cranking over I can build 15lbs oil pressure according to the gauge so I'm fairly comfortable with that (That is better then my '68 Mustang gets on a hot day after a long drive :roll: )

Thanks for the idea,
-ron
 
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