Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

i have an old dynamark lawn tractor. it has a tecumseh 12 horse ohv 12 model number 202714a. i just got in a trade on a antique motorcycle basket case.i did  a good cleaning of the carb and cant get it to stop surging.the governor surges back and forth and the carb sometimes spits back.do i need to rebuild the carb?do i need to adjust the valves?what are the specs and part numbers?

Your carb is still dirty, try re-cleaning the main jet.  make sure carb cleaner is flows throught the small holes near the throttle butterfly in the carb throat.  (they control the idle mixure).

your engine is running too lean at low speed,  the govenor is opening up to reestablish speed,  it trys to rev on the higher throttle setting and recorrects back to the lower speed it can't maintain.

it will surge untill the low speed jet delivers fuel at the right amount..

The low speed jet receives all of it's fuel from the main jet "plumming"  (the calibrated hole in the carb post sticking into the bowl, or threaded jet into it)

Good Luck

Friiy

Parts ipc  cut/paste

http://www.outdoordistributors.com/pdf/Tecumseh/TECUMSEH-MODEL-OHV12-202714A-PARTS-LIST.pdf