You need to reattach the retainer back onto the fuel line at the carb. This will help keep the primer hose from contacting the govenor which can produce a throttle issue.
hay Doug try takeing a pipe-cleaner(shannnneeelle stems)(sold an jo-an fabrics) and run it trugh the carb jetsBy now, I am certain that enough has been typed regarding the Duraforce surge. Having said that... here is my story.
I have a used 2001 Duraforce that I paid $25.00 for. The mower would not start. I removed and cleaned the carb AND the two jets. I replaced the seat and valve, installed an in-line filter and shut off valve and replaced all carb gaskets. (I didn't replace the float.) I verified that the flywheel shear pin was in good shape and installed a filter material in the primer bulb. As well, I ensured that the gap of the spark plug was .030 and the air gap of the flywheel was the gap of a business card. I washed, cleaned and dried the fuel tank. The upper and lower seals looked good with no oil leakage. Finally, I ensured that the exhaust port and muffler tube was clear. (It was VERY clean and clear.)
After my repairs, it started on the first pull. (I run 35/1 Mobile 2T oil, 87 octane fuel) I adjusted the mower to 3,100 rpms in the fast mode. The mower surges a little in the fast and mid-range. (It drives me nuts.) The slow speed is fine with a nice burble.
I spoke to a small engine mechanic who works on LBs and explained the lean theory. He laughed and stated that the fix is most always to replace the gov spring. I will try this next week.
Comments welcomed on the gov spring replacement theory to fix the surge.
By the way, I am not a fan of the LARGE rear wheels you see.