[AT] Covid-19 Quarantine tractor project

[Spencer Yost]

So I took a break from the motorcycle tonight and moved to the 430.  

After I got the engine unstuck a few years ago I did a static timing of the ignition; but I never did do a running timing. First of all I had still needed to clean and adjust the carb and plus I wanted a few hours of running on it before I did a true running timing on it.

As you can guess, I never got around to it.  (-:

While the static timing  was close I got a sense of misfire at high idle.  Not a true misfire but not “right” either.

The 430 is an engine that you time at full open throttle, no-load RPMs.  The service manual provides PTO shaft speeds that correspond with engine speeds which is helpful because my tachometer busted probably 15 years ago.   So I opted for the shaft conversion table.   But my shaft contact tachometer was borrowed by a friend in the 90s and it disappeared( Not his fault:  he became quite ill and eventually passed and I didn’t have the heart to bother him or his widow for it or several other tools).  So I bought an optical tachometer from Harbor Freight several months back for this task.

I put a piece of reflective tape that came with the optical tachometer on the PTO shaft and used that table in the manual to double check idle and full throttle, no load RPMs.  The optical tachometer did fine, but as the reviews of the product indicate you do want the area to be fairly dark, and you want to be holding it exactly perpendicular to the axis of the shaft.  It also helps to brace your arm while your hold it.

For reasons I do not remember, I had to adjust the governor shaft when I was done unsticking the engine and preparing it for test runs. So my high idle RPM was actually dead on. But it definitely took some futzing with the carburetor to get my idle speed right. 

I needed to do a good bit of adjustment of the distributor to get the timing mark to come up.   I would say a 5 to 10° turn. It now idles without “loping” and runs at full throttle without a hint of that misfire sound.

A good day.

Spencer

Sent from my iPhone