TO 30 Bubbling sediment bowl, power loss

Engine starts surging and losing power.

I observed the linkage, governor, etc. All working.

Then I noticed the sediment bowl. Every time the engine surges/changes speed - the sediment bowl looks like it has a tornado in it. You can see bubbles enter and the gas swirl. I can't tell if the pressure is comeing from the engine side or the tank side - but I'd guess the engine side.

When it is running normally the sediment bowl is quiet looking

After resting it for a while it is ready to go again.

I've a infra-red thermometer - I checked the tank temp - it was 104 when working and 110 when it stalls

the fuel line between the carb and the sediment bowl was 180 when working and 207 when it stalls (taken by the back corner of engine)

the carb fuel bowl was 140 when working and 204 when it stalls

I had the radiator pulled, cleaned,etc., and installed a new 180 degree thermostat. The carb was rebuilt (by a tractor shop) last year.

I sure could use some help....

thanks in advance

Dave

p.s. I've had this tractor since 1980 - this is the first year I've had this problem.....

I would suggest that the heat build-up problem may be due to a faulty thermostat, since you just replaced that. Did you check if for correct operation prior to installation? It would be the first time that they were not proper out of the box. Remove it, and on the stove top, put it some water and bring to temp. Measure water temp with a thermometer and watch when it opens.

Note: best done while wife is on shopping trip, clean up afterwards. :)

Jeff