Plug fouling Tecumseh 6.5hp

[bobber]

I have a 6.5 hp Tecumseh that keeps fouling plugs. I ride for 10 to 20 min. & the plug is covered in carbon. I clean it & go again with the same results. It has a non adjustable carb, which has just had new O-rings & jets cleaned. Can anyone give any suggestions? If not enough info please ask for more so I can solve this problem quickly.
Thanks so much.

Danny

 

[Kenny_McCormic]

Oil burner? Put a platinum fine tip plug in it, unfoulable.

 

[Russ2251]

Is air cleaner in place and is it clean? Is heat range of plug correct?
Carbon on plug indicates a rich condition.

 

[bobber]

I'll try the platinum fine tip plug.
Not sure about the heat range. Brand new air cleaner. The lawn mower shop gave me the plug that comes stock on the engine.
I guess there is no way to lean out the carb. Is there any other reason it runs rich besides the carb? How would you go about fixing this, would the platinum fine tip plug do the trick?

thanks

 

[Russ2251]

Is carbon on plug a recent development? Or has it been a problem since day one?
Any black or blue smoking out exhaust?
Make sure choke is fully open once it is warmed up.

 

[bobber]

This is new to me. It also has a choke-less carb. Primer ball is all it has. I asked a guy at a lawn mower shop how to adjust rich & lean. He said the only thing you can adjust on this carb s the idle. It is a Yerf-Dog cart I picked up to ride around the neighborhood.
Model # on cart is 3203. It was used but in great condition.

 

[bobber]

Also, no smoke out of exhaust.

 

[Russ2251]

I'm leaning towards a faulty float level.
Need more info. Got an engine number?
Something like OH195EP-71805B.
Look carefully, usually on flywheel housing.

 

[bobber]

When I ordered a part, they found it listed under this number.
71711C
Spark plug is Champion RN4C

 

[bobber]

Model OHH65
Spec 71711C
Engine Family 2TPXS.19151AB
DOM 02058CD0252

That's all the Numbers I found on the label on the engine.

Thanks

 

[Russ2251]

Yup, It is an emissions carb.
If your absolutely sure everything else is correct and operating, then debris in carb and/or float level is likely culprit.

 

[bobber]

I read something that said remove the carb, flip it upside down, put a 11/16" (i think) across the rim of the bowl & the float should just sit on the bit. If it doesn't bend the float mount until it does. does that sound right?

 

[Russ2251]

Generally correct. 11/16" may or may not be correct for your specific carb.
Check for sticking needle while it's apart and that float actually floats.

 

[bobber]

It was actually 11/64. The bowl was way off. I bent the tab to get the bowl down where it needs to be. I also found a piece of old O-ring from the little red plastic jet stuck in the carb. Now I need some fuel line to replace the one I tore when removing it and hopefully no more problem.

Thanks for your help. I'll let you know what happens when I get some fuel line.

Danny

 

[Kenny_McCormic]

Replace with TYGON fuel line. Best stuff since sliced bread.

 

[Russ2251]

If your so inclined, get an adjustable carb.
Many different carbs out there that will fit. Just have to make sure that venturi size is the same.
Venturi is the narrowest part in throat of carb body.
If venturi is too small, power will be restricted. Generally, engine manufactures make them smaller than what engine can actually handle. A kind of 'hard wired' governor.
If venturi is too large, engine will run lean.
Be aware that if you change carbs, linkage may/may not match up. Could render governor unusable.

 

[bobber]

Well, I got all the remaining O-ring out. Got a new fuel line. Put it back together and it was a lot better, but still had some sputtering after a short ride. Plug still had some carbon build up that when cleaned ran without sputtering. The lawn mower shop suggested Sea Foam. I put some in the tank & ran it though. Then took it for a good ride. This time the plug is clean. I don't know if the problem is solved or not but it was nice to take a decent ride and not foul the plug in a matter of minutes.
Thanks for your help & suggestions.