TC300 fuel delivery issues

[Eddles]

Hi all,

Recently brought a mower with a Tecumseh TC300 engine, seller said it was fully serviced, was squeaky clean and ran fine when I picked it up. Works great, but has occasional issues with fuel delivery. For example, when I ran out of fuel, I refill and I prime the engine, it starts and runs for about half a second before stopping. Repeat ad infinitum. However if I start it, and quickly poke the primer bulb before the engine stops, it'd run fast briefly and start to stall, until I poke the primer bulb and it'd do the same. Took me 20 mins trying to clear the fuel lines before it'd start and run without any issues.

Last time, it started instantly, no problems, ran for about 45 minutes then started to struggle - if I tilted the mower to the side so the blade is off the ground, it'd run smoothly, then when I put it back down and start to mow again on an easy patch, it'd slow down almost to the point of stalling and I have to tilt it again to speed up the engine. Eventually I gave up, and left the mower for a hour while I did other tasks. Came back to it, and it started and ran perfectly.

Another time, it ran one full tank fine, didn't run out of fuel, added in fuel and then it started to hesitate and surge.

So my questions are:

1) If I run out of fuel, how best to clear the fuel lines of air?
2) The pipe leading to the primer bulb has lots of air bubbles in that I never could get cleared, should this be cleared? If so, how?
3) The fuel tank leaks at the bottom so I store the mower almost upside-down, would this affect the fuel system, and cause the issues above? If so, until I manage to buy a new fuel tank, how to clear the issues? It's proving very difficult to find the correct fuel tank as most TC300 engines has a side mounted fuel tank, while mine has a rear mounted fuel tank.

Thanks for your advice in advance!

 

[jp1961]

One item you can try (before removing the carb from the engine), is remove the fuel line and spray some carb/choke cleaning into the fuel inlet. Diaphragm type carbs can be finicky and susceptible to dirt, more so than float type carbs. The leaking fuel tank could be causing the problem.

 

[Eddles]

One item you can try (before removing the carb from the engine), is remove the fuel line and spray some carb/choke cleaning into the fuel inlet. Diaphragm type carbs can be finicky and susceptible to dirt, more so than float type carbs. The leaking fuel tank could be causing the problem.

Hi, thanks for your response!

I've removed the tank, don't believe the leak is the problem as the fuel filter protudes through a hole at the bottom, the fuel line goes into the fuel filter barb, the leak is coming through the hole on the outside of the hose. The fuel flows very well out of the hose at the carb end.

I've used liberal amounts of carb cleaner through the inlet and air horn, the engine starts well, runs on the remnants of the cleaner and then stops. I use the primer and then try to start it again and it refuses to start. I'm pretty certain the primer bulb isn't doing anything as there's a small bubble in the fuel supply line and it doesn't move at all when I poke the bulb. The bulb feels as if it's full of air, and the primer line has no fuel in at all. I think I need to prime the bulb and line with fuel, but how? I've taken a picture of the carb - the mower is upside-down, but I obviously prime and start it the right way round. Any help would be greatly appreciated!

 

[jp1961]

My Intertec repair manual covers the TC200 model not the TC300, but I suspect the carbs are similar. The idle mixture needle is one turn open from a lightly seated position. I'd try removing it, and spray some gumout carb cleaner in the hole. Another item to check is the diaphragm, if there is even a tiny hole, it will not pump gas from the tank. I have a TC300 engine on a string trimmer, the fuel bulb is squeezed, not pushed in like most primer bulbs.

Jeff