I have to ease the blade engagement in or she dies. Also as I cut it tends to throttle down then back up. I notice that linkage between the governor and carb is loose. There seems to be no tension on the spring from the governor arm. My guess is that there is too much slop in the linkage. Any help would be appreciated.

Next I would look for the adjustment screw sticking straight out at you, when you face the intake manifold side of the engine, at the base of the carb, turn this screw 1/8 turn counter clockwise and see if this helps.

You are sure the engine is running on BOTH cylinders?

Walt Conner

This is a used engine that I just got running. So far

New coil
new plugs
changed oil.

The symptoms are as follows.

Starts easily, no smoke from exhaust, idles well. I bring up the speed and it responds. When i attempt to engage the blades it tries to die. If I ease it in the motor will continue to run, it seems to have plenty of power (Goes up a fairly steep incline with blades engaged).

The motor periodically will slow down for a few seconds then rev back up under load.

Tomorrow I will buy a carb kit, clean the carb, rebuild the fuel pump, and replace the pulse hose.

The slack I was referring to turns out to be the high speed adjustment screw, not the governor spring (Newbie here) it is loose and not contacting the bracket. ( possibly not running at high enough rpm?)

Any other suggestions?

ALSO, sudden opening of the governor (throttle) may cause lean mixture temporarily, OR if the governor does not respond quickly enough to pick up the load, engine may stall. This is controlled by the position of the governor spring in the holes of the governor arm. In closer to shaft makes quicker response, farther out, slower response. Note that this will also affect engine top speed and other adjustments will need to be made on opposite end of governor spring to compensate for this. Normal position of spring is in middle holes of governor arm.

Cleaning and re-kitting the carb may solve your problems, running Seafoam in the fuel for a few tanks per instructions on the can might do the job as well.

Walt Conner

I played around for a while and discovered that if I only brought her up to about 75% throttle she ran like a dream.

I readjusted the throttle linkage so that i got maximum RPMs at 3/4 throttle and it ran fine. It then occurred to me that this tractor orginally had a 31d707 briggs, that engine had the choke built into the throttle linkage. It seems that by bringing the throttle lever all the way up I was causing the spring from the governor arm to end up in an unnatural position. (way to much travel from the throttle control).

I installed a stop on the throttle control to prevent it from being put in the previous "choke" position and things are going great. Cut the yard tonight and only had an occasional shudder. I can engage the blades, cut up a hill satisfactorally.

To put it in a nutshell, excessive throttle travel caused the spring from the governor arm to end up way passed where it should have been, AND the pin on the governor arm actually ended up bypassing the sheet metal cam on the throttle linkage, this allowed the governor to overshoot causing surging.

Thanks for all the help, this is my very first lawn tractor, 2006 troy bilt, the mower was free and I have about $110.00 in the replacement engine.