HM100 woes

[VegetiveSteam]

Sometimes your choices are few and you have to move on but I'm disappointed we couldn't be much help to you on figuring this one out. I think you definitely ruled out carburetion.

 

[Forest#2]

I know the sputtering Tecumseh engine is gone.
Here is couple of links to videos of how a carb MIGHT can be modded to fix a sputtering hunting engine that is running lean.
This is the basics to what I did to my HM100 Tecumseh carb idle jet.
My Tecumseh carb jet was similar to the Kohler/Honda but all brass.


How to fix/mod a one barrel surging Nikki carb used on Briggs single cylinder engines link. See post number 9 for the video



The OEM jet size was .015 and he ended up at .034

https://www.mytractorforum.com/threads/scotts-by-john-deere-surging.1352937/



For a Kohler/Honda style carb surging mod. Jet size was .015 and went to .028