M8T Kohler question

[stevewarner1957]

I have a Troy Bilt Horse tiller I bought new in 1992. It has the Kohler M8T recoil start engine. Last year it started kicking back when cranking. It would pull the handle out of your hand or pull the rope out of the handle. This issue got worse this year and messed the recoil spool up. I decided to get to the bottom of the issue. I pulled the flywheel and the key was perfect. I pulled the head and cleaned up carbon. No issue found under the head so I replaced the head gasket. I pulled the oil pan and checked the ACR spring. No problem found. The valves are not adjustable on the M series but I checked the gap and it was within spec. So today I put it all together and used the recoil cord and wrapped it around the cup on the flywheel and started it old school. Before I find a recoil off a junk engine, new ones are not available from Kohler for M series, what are your thoughts on this kickback issue? I have run out of ideas. If necessary I can continue to old school wrap start as I don’t want to tear up another recoil. Thanks in advance for any help

 

[radios1]

the only thing left for ignition timing is the spark coil, there are pulse shaping components in there that vary the dwell time(longer for idle, shorter for full speed) that may have gone bad, and advanced your timing!. but I'd scrap an engine that new parts cannot be bought for, and the rope around the cup of the flywheel method can mangle you hand if it gets pulled into the cup!. accidents DO happen!..

 

[stevewarner1957]

I hate to scrap it as I have really maintained this tiller since new. It looks like new inside. It does aggregate me that there in little support from Kohler on the M series. Still lots available for the old K series. I would like to do a GX Honda repower!
Here’s a pic of the flywheel/key

 

[Gem99ultra]

Recoil kickback tells me that the spark timing is advanced too much. For what reason, I don't know. But that would be the first thing that I'd look into. It sounds like you have a good power plant that is worth saving.

 

[stevewarner1957]

I agree, advanced timing. It appears that the coil is all that's left to change. I was unaware it could advance or ****** timing. It's worth a shot prior to putting another recoil on Thanks