All my lawnboys had sat from last Thanksgiving until this spring with dry tanks. The Dura Force started in 2 pulls. All 8 of the others (that were ready to run at that time) started with 1 or 2 pulls except the L21ZPNC and it took 3 pulls. All these were F's.
I have an 89 S21ESN, well, the deck, handle and wheels anyway. 92 engine with low hours, new starter, battery, transmission. Added a pull start, on/off toggle switch, bottom oil seal, and spiked the wheels with drywall screws.
The muffler is rotten so it sounds like a rough idling snowmobile. Starts almost instantly with the key, and always with one pull of the rope. It's my ditch mower- I have about 300 feet of steep ditches, and it literally DRAGS me along behind it! Ugly, sounds awful, best machine I've ever owned!:bannana:
I never had hardly a lick of trouble with a D-400. Only once in a while the advance cam doesn't slide decent, and they'll sputter and backfire till it finally slides free to advance the spark. Other than that, I'd say they were the most reliable. No CDI packs to fail, and very good carburetors.
I'd have to say that the E engines get a thumbs down - due to the super-weak coils. Never had any of the old points-ignition types, but I've also never had a problem with my F engines. They may leak a little, but they always fire up if they've got a clean carb. Props to the one pull fools!
The old points ignition systems were rock solid. Once in a while you might get a condenser failure, but it's no more common than a CDI pack going bad.
Duraforce engines are nice and powerful, but I've seen so many that are blown up, surge, leak or have bad coils that I'll have to agree that they are FAR from reliable. But then again, they were designed by the same geniuses who designed the V........
My dad bought a 1967 Lawn Boy. The on/off switch broke years ago. The handle had to be shortened and new holes drilled several tiimes. I shut it off by shutting off the gas. It was a great trim mower. Yellow in color and always ran. Pushed easy. I sold it at a garage sale last year. I had bought a new shelf propelled one the year before. My brother and dad have the same model. Great push mowers.