Ford 172 starter eater

[krusty]

Spring is here finally.....

3rd week of Jan and there was minimal snow on the ground so I went out and felled a bunch of trees with plans to skid them over the rest of winter. Then it seemed to never stop snowing and they are starting to appear again and have been skidding. TJ200 with the 172 gas and my starter last winter blew the bendix so I got another starter with the bendix on it.

A couple weeks ago I blew the bendix again. On cold days I have to choke the machine to start, almost full choke. But the poor starter lugs and the engine kicked back and blew the teeth out on the bendix. So this time I just put a new bendix on it. Today went to start it and it struggled to spin with my battery and full choke. So I popped in a nice group 31 batter and it certainly did spin it over when choked right until the engine kicked back and blew the teeth out again. 

I did not take the starter out but assuming that is what happened.

Any idea what is going on? It only struggles to turn the engine when full choke is on. Then it may fire or kick back. There were a few days where it was real cold out and I put a propane heater on the engine for 30 mins and it warmed it up enough to fire without choke required.

Once it is running, it runs great.

Wisdom appreciated.

[Riwaka]

Sounds like the engine block/ oil prefers to be pre-heated in cold weather prior to starting with the propane heaters. 

Backfires might something about a lean mix when starting in the very cold conditions.
Carburetor heat - Wikipedia
Tech Tip #132: How To Prevent Zenith Carburetor Icing | Foley Marine & Industrial Engines

https://www.motionaero.com/dual-heat.html

engine block heaters etc

[Ed_K]

 I have a massy gas engine that I change the timing for winter. I think I retarded it. It turns over easier.

[luap]

kick back is a timing issue either ignition and or valve.

[Highhood]

I had a four cylinder gas in an old Jeep that was hard on starters and I found when I replaced the clutch, most of the flywheel teeth were gone in one spot. 
Like others said maybe a valve issue — pull plugs and do a compression test. 
Your backfire issue might be something entirely different like crossfire in the distributor cap. I pulled the points out of my 172 in my 15 and put in one of those Prestolite electronic ignition units, new cap and wires. It seems to make it start a lot easier and more reliable. 

[Highhood]

That electronic ignition module was a Pertronix not Prestolite. Just wanted to correct my mistake on previous post. 

[moodnacreek]

Had a IH 350 U that would break the starters. [no kick back problems]. Turned out to be the ring gear.

[luap]

to address your issue you should get the specs or a manual and check all the basics. Set all the valve clearances, Normal movement of all valves? make sure the rotor is lined up when the piston is at top dead center. tune up stuff first. with the plugs out crank it over and does any liquid come out? When you bought the new starter did you check new and old side x side? Did you buy oem, refurbished ,or rebuilt? I have had starters same part number but different nose cones. Do a google search on any part numbers you have plus manufacturer and you may be surprised on the choices you have besides going to your local dealer. I had a starter problem on a ford 351m. starter would kick out or not engage. replaced ring gear, battery cables, solenoid. What cured it was new bearings in the new oem starter. There was to much clearance in the bearings which allowed sloppy gear tooth engagement Made me wonder if their supplier for oem was just a clone, same as I could find on google.