Can someone please confirm the firing order for a 1935 R5 Caterpillar? Nothing on the block and can't seam to find it online. Thanks in advance!

An R4 is 1-3-4-2 if that helps.

Thank you for the reply. I did have the firing order correct, on the R5 it is 1243. First off, I am a competent wrench but I am relatively new to old iron. I have been helping my 93 year old uncle prepare for an auction. He worked on this R5 probably 25 years ago and got it running but it never ran well.After painting it was parked on the front lawn as an ornament. Fast forward to now and I am trying to get it to go. After going though the carb three times it would run but seemed to labor and buck anything I tried to do. Seemed like a fuel problem but nothing helped. My uncle said it sounded like the ignition was retarded to much but hey, the mag is either on or 180 off, right?

I have become a self proclaimed magneto expert in a very short time getting a number of old machines running. Timing seemed off but how could it? On an R5 the mag shaft comes out of the governor housing, through the water pump, and to the mag coupling.  After close inspection, at the coupling there is a keyed bushing and over it is a splined split outer coupling. Advancing the timing at this point got it running, advancing it more got it running even better. The timing was probably messed up when my uncle bought it decades ago.

I have had to remind myself of the basics. Spark (at the right time), fuel, and compression. No computers or sensors to confuse the diagnosis. I LIKE THAT!

Hi,
correct ignition timing would be 30# before top dead center No1 compression stroke--timing mark "MAG" stamped into flywheel is 30# BTDC--set on No1 compression stroke at which time the magneto points should open and the distributor disc segment for No1 Cyl. should also be in alignment with No1 plug lead tower carbon pickup.
NOTE :- provided the flywheel is timed correctly to the crank for No1 being correct otherwise you will need to do your own timing correction by piston travel or other means.
This 30# BTDC is taken from my Grey colored R5,Thirty Five and Forty Tractors Operator's Instructions book, Form No 30610, Dated 10-52.

Hope this helps.
Cheers,
Eddie B.

Thank you for that information Eddie. I will try to dial in the timing again today. I also need to adjust the governor to get it to idle down better. Time is running short as the auction is coming up soon. Now a Farmall H that was running great has become jealous of all the attention the R5 is getting and has an attitude.

Here is a picture of the plow. It came from the Forest Service in the Chequamogan National Forest here in north central Wisconsin.