Craftsman 6.5 HP B&S Motor Surges, Have I Tried Everything?

[Scrubcadet10]

Thank you for coming back and letting us know that, and how, you fixed it.

 

[slomo]

It Runs!
I replaced the intake manifold gasket and put in an OEM B&S carb ($38) and it ran for a full hour without any real surging. I did notice a tiny bit of surge when I tilt the front wheels off the ground to turn it, but otherwise runs smoothly. The existing intake manifold gasket seemed pretty tight and fully intact, but it came off in bits, so maybe it had hardened or shrunk. Since I replaced both carb and gasket simultaneously, I can't say for sure which solved it, but I'm guessing it was the carb. Lesson learned, don't bother with the cheap aftermarket carbs, a real crapshoot quality-wise.

Thanks for advice, All.

Very well could of been a float setting or pilot jet setting if adjustable on your carb. Either way, good to know it's running now.

slomo

 

[Rivets]

Congratulations.

 

[slomo]

Might be missing that small throttle return spring in the linkage. Make sure all the carb linkage and springs are proper.

slomo

 

[earlkuykendall2015@gmail.]

Have you pulled the fuel line off the carb and checked the fuel flow. I have seen crapped up tanks have very small fuel flow and what happens is the unit sets for a few minutes and the carb fills up and engine starts and runs till float bowl runs out of gas then when it sets for a few mi s it will start again. You can't use air to clean the tank. If it sat and dried and varnished that crap will keep coming loose.

I had an experience just like this on a craftsman, I replaced the entire gas nine, filter and shutoff, now runs much better, I did notice that the fuel tank had a rubber insert and washer, I do believe it had contributed to this problem, I changed out tanks with a tank that just has the plastic nipple, I would check this as well.