The guaranteed to start mower does start, but it won’t run well enough to mow. This is a makeshift repair, temporary fix, or out of warranty fix for a Toro SR4 lawnmower that runs poorly (spitting an sputtering) and has throttle or speed limiter problem. This is a jury rig type fix that I was forced into when the mechanic, at the place I bought the mower from, treated me like crap, wouldn’t listen to me, criticized me, and almost claimed the problem was me. His solutions were wrong and I pretty much knew it, but what do you say to an arrogant mechanic. For me it was “Bye” not buy.
The fix is very simple by adding a short piece of wire to replace a spring. It keeps the throttle in one position where the motor runs best. You can find the proper setting by adjusting the throttle till the engine runs smoothly which is demonstrated in the video. I don’t recommend this fix, especially if the mower is still under warranty.