OK, I have been fooling with small engines my entire life. Lawn mowers, outboards, snow blowers, mini-bikes, weed-wackers, 2 cycle and 4 cycle. This has me stumped. My daughter has two mowers at her place, a self-propelled Troy-Built, and a walk behind Sears. Neither would start. Sometimes the Sears would start, run a couple of minutes, then die for the rest of the day. I started on the Sears because it actually showed life was easier to get at stuff. I cleaned the jet. Nothing. I re-built the whole carb. Nothing. The primer pumped fuel just fine. I tested for spark and it was solid every time. Changed spark plug. Nothing. WTF? So I have an old power washer I saved by replacing the carb with a spare mower carb I had. The Sears and the PW had Tecumseh engines and identical carbs. In fact the carb I used was from the same model Sears mower so a logical test piece. I put the PW carb on the mower. Nothing. I put the mower carb on the PW. Bango! She started and ran great. So both carbs ran great on the PW but the mower stayed dead. Now I am getting pissed. I am looking at everything now and that was when I realized it was making a squeeking sound when I pulled on the rope. Just for the hell of it I check the oil. OMG! Empty! I A-ss-u-med there was oil- there was not. But OK- that would not keep it from starting. It would cause it to break, but it should run. Well I filled it with oil and tried it. The $#!^%&* thing came to life! WHY!?! I never heard of a low-oil-moron-proof-cut-off feature. I cut my whole lawn and it never faltered like nothing was ever wrong. Then I went to the Troy-Built and checked the oil. EMPTY!!! I filled it with oil and it started right up! WTF?!? The PW that worked was low too but not dry like these mowers. So OK mechanical type guys- why is this? Since when does no oil cause a no start condition?
