Small Engines (Lawn Mowers, etc.): toro s-620, steve crane, valve clearances

Question
Hey John I have, well my brother in-law has a toro s-620 he said i wouldn't run good, me and my bright self said hey i can fix it throw it in my truck so here I am two days into it and it wasn't as simple as I thought, I have found many of these and just replace the needle and diaphram and they worked so with this thats what i've done! I never started it before because it didn't have gas in it so I figured that would be ok so I just ran it to the basement grabbed the parts and installed!!  Well there seemed to be tons of oil all over this machine, I found the exhaust not tightened to the cylinder head so I figured thats where the oil was coming from and snugged it back tight, I fired it up today and it ran good then I put a load on it,"just lifting it up", and it would back fire and stop, this also happened when I just let it run for 5 minutes it back fires and stops!! I have read something about Welch plugs could one be missing! I did read some of your post and maybe just better off taking the carb. off any help would be appreciated!!   Steve Crane

Answer
Hello Steve:

>>Send me the Model Numbers Off the Unit, Please. With these I can Locate the Correct Manual and Better Assist you.
>>The Backfiring and Stalling can be a Carburetor Problem, Flywheel Key Damaged, Valve Clearances Require Setting and Several Other Items Depending on the Units Model Number.
>>**If you Need Assistance in Locating the Model Numbers, then You can Go to this Site Addy; https://lookup3.toro.com/partdex/default.cfm and Select Step 1.**  
>>The S-620 is the Series Model Number.
>>Thanks

Respectfully

John

>>PS: I am Allowed to Answer 3 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Follow Up Questions are Now Received Anytime. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John