Mr.

[bobmiller]

Hi ALL,
I have a 1974 Cub Cadet Model 129, 12 HP Kohler.
It runs great mowing for 30-40minutes then it starts missing and blowing
smoke. Could the engine require an overhaul?, or rings or valves or what?

 

[Muhammad]

Welcome to TBN.

 

[Briana03]

Hello & WELCOME to TBN!

I moved your thread to the Cub Cadet Forum.

 

[OldMachinist]

It might just be overheating. Remove the engine shoulding and clean all the cooling fins.

 

[rcbe]

OP - might also try checking fuel tank cap vent blocked by running with same loose...

 

[savageactor7]

Disconnect and blow out the fuel line while your at it... riffing on rcbe's response.