Cold weather start problem

[JWR]

Tried again temp in mid 20's turns over fine sounds like it wants to start but no go. Put new spark plugs in and new fuel filter , checked spark and it was real strong at both cylinders , tried using starting fluid still would not start.

Being gas, you might have ice in the filter or? Most anywhere in the fuel path a tiny bit of water can do this.

After more thought, I'm guessing your carb float is not fully opening or stuck shut. It lets in a little gas, you run the engine a minute or two and use that gas and the float valve is either gagging on something or not opening for whatever reason. If it sits a while a trickle of fuel gets in to the bowl and you can keep repeating this forever. If nothing else shows, I'd disassemble the carb and see if the float valve is free or not. I had an OLD MH with a Continental 4 cyl which would starve out of fuel, I'd hit the cast iron bowl a whack with a crescent wrench and it would then run for a while. Rebuilds never cured the issue. Finally decades later I used some Seafoam additive in the gas and the problem went away. I'm no fan of additives either.

 

[ernemats]

Temperature hit 60 degrees today so I decided to mess with the 422 today, put new spark plugs in it several days ago and talked to Terry and he said to try starting it with choke off and 1/4 throttle tried it did not start then put choke about half on and gave it a little more throttle and it started weakly as long as starter was engaged then it would shut off. Tried hitting starter again and it started weakly and then it kept running weakly and after about a minute it started running normally. Left it running about half throttle for 5 minutes then shut it off and restarted it several times and ran it around outside for a while and it seems ok. Don't know what problem was but I hope it continues working. Only thing I notice is if you have ir running at idle speed and then open it up wide black smoke shoots out the exhaust momentarily

 

[JWR]

The black smoke after running a while and then hitting the gas is probably just carbon that built up over the lengthy period of not running and never clearing it's throat so to speak. Several cycles of goosing it and that should go away. When I was young (6 or 7 decades ago) that was called "blowing out the carbon." Hot rod teens have been known to use that as an excuse of course. Never know for sure, but it sounds to me like you started out with a tiny bit of water frozen somewhere in the fuel path. Once that thawed you were initially getting a carburetor bowl that had some water in it and marginal rpm from your starter so it would only keep running with help of the starter -- not self sufficient combustion going on. It probably needed more choke then too and finally did run once you gave it enough choke and continued rpms. Your friend Terry was (probably) saying try with the choke off because he thought it was flooded. Evidently that was not the case. Ah, the pleasant experiences with old tractors ! I would go ahead even now and run some water absorbing additive through it.