WD45 No start mystery

Long post, read carefully.

A few months ago I picked up a nice original WD45.  Bad wiring and a sticky starter did not make it start at the auction.  However, I pulled it 6', jumped the clutch and drove it home.  The engine ran beautifully.  I have not run it since this time.

Here is what I have done in the last 2 months:
Cleaned out fuel tank and sediment bowl
Rebuilt carb
Blew through fuel line and topped up tank with fresh fuel right from the gas station
Completely new wiring harness
New key switch
New ammeter
New light switch
New thicker battery cables
New battery (came with tractor)
Rebuilt starter
New spark plugs
New plug wires
New 12 volt coil with internal resistor
New distributor cap and rotor
New Pertronix 12 volt (Negative ground) electronic ignition
New engine oil and filter
Boiled out rad and new coolant
New Nelson muffler
Rebuilt generator, new voltage regulator, new fan belt

With all of this new stuff, you would think it would start right up (other tractors usually do).  For the life of me, I cannot get it to fire.  It cranks over great, but it backfires and spits flame out the air tube of the carburetor.
I am getting tons of spark at the plugs thanks to the EI and the carb is getting lots of gas.  I even put the carb on from my 54 WD45 (which I know is set properly and works great) - no change.  Putting my hand over the air tube of the carb while cranking gave lots of suction, indicating no blockage in the intake.
Thinking it was a valve issue, I popped off the valve cover and checked out the pushrods and valves for proper movement.  Nothing stuck and the head looks real clean inside.
I have hit the wall.  I cannot think of anything else to check or what could be the problem.
Any ideas on where to go from here?

Sounds like you gotta couple plug wires crossed or maybe all 4 off 1 hole on the dist cap.

OUT OF TIME.       MACK

Timing is off. The wires may not be positioned exactly the same  as your other WD 45. Find TDC on number one and go from there.

DSeries4 wrote: Timing was not disturbed.  Spark plug wires were ran exactly like the ones on my 1954 WD45.  Helps to have the same tractor which runs!

 If you didn't replace the plug wires one at a time, but pulled the whole works and put them back in order by looking at another tractor, you have no way of knowing they are in the right position.
 Take the #1 plug out and hand crank it till you feel compression on that cylinder. Bring it to the top of the stroke and look where the rotor is pointing. THAT is where the wire for #! has to go. Follow clockwise around the distributor by firing order for the rest of the plugs.


Edited by CTuckerNWIL - 08 Jul 2017 at 6:53am

I have done a couple of these pertronix installs in cars recently. Had to reset timing in both cases. Maybe that is all thats wrong here. Once timing was set they worked well and no issues so far. Lately I see some problems on our site here tho. 

Sounds GREAT Myron!!  Amazing what one little ole hole will do to them.

Motor sounds great.  Always feels so good to get them purring!

Steve in NJ wrote: Hey, we're all human. Happens to the best of us including myself. Been a mechanic for 50 years, still sometimes screw up a firing order once in a while or do something dumb! Sometimes ya stand there saying "I don't believe I did that"! But you did!!  LOL!  Now that its running nice, its time for a paint job! I know what you'll be doin' this Winter!  Keep us posted Myron! You guys do some beautiful work man!  Steve@B&B

Sorry Steve, no fresh paint on this bird.  Keeping it's original patina.  I'll probably try waxing or buffing the 60 year old paint out a bit.  Still trying to get my 190XT together and out of the shop.  This WD45 didn't help that effort!

I see from the video that the distributor is turned 180 degrees from where it usually would be timed.  Makes no difference in how the tractor runs, but if you change it around, you'll have a little slack in #4 spark plug wire anyway!!  LOL