Dotty, 1. Can you summarize what the 2nd repair shop found as the problem or problems and Fixes? I have an MTD 21” mower I have used just at the start of the season to collect leaves. I have dreaded the 2-3 pulls to start the mower with fresh Stabil treated fuel (after leaving some in the mower treated for a year, thinking varnish vs moisture). I should have been leaving a full tank to not draw moisture or Bone Dry. Once start, it feels easy like it has compression release. I plan to start rotating my 2 mower vs letting the MTD sit and the Murray has always been first pull. Since the mid 60s I have had some “Kickbacks and they all were Tecumseh engines from my memory vs Briggs. I got bold and started my MTD with a ½ drill (with a side handle in case it kicked back. It had never kicked back and it started. I am not promoting the drill but I am suggesting electric start if there is a kit for your tiller. I put my recoil starter back on using 1/4 X 20 bolts clips to thread the bolts into. I did this a week ago and it started 1st pull today. I pulled too harder. LOL!

I have not gotten into the Mac 10-10 at this point far enough to know the vintage, but, the price was right. I had to dispose of some copper at our local recycler. Anyway, while there I am always nosing around for stuff! Looked in the aluminum pile and there were about 15 Poulans, all apart, and this one vintage Mac 10-10! It had a repair tag on it and the pull rope was broken. Traded the copper for the Mac, got it home, cleaned it up, got the old rope out and replaced, cleaned out all the oily sawdust residue, put it together, filled it with, 20:1 and chain oil, and to my amazement, 3 pulls and it was off and running. This model has the chain brake and left side start pull. Any help on the vintage is welcome. Serial number 13-34485 and Model # 6000130 I think.

mvron: The 36 cc.1610 was introduced in 1977 and the 69 cc was introduced in 1969 . My Uncle had a 1645 Model . It was a rather stout unit made in British Columbia Canada. I would not sweat the Unleaded Fuel since your dealing with a two stroke engine , no valves requiring protection . Just ensure a preimium grade oil . I would run synthetic at 40:1 Ratio. I run 50:1 Amsoil Sabre Syn oil in both my Vintage 1967 Pioneers .

I have an 034AV Stihl that was bought new... the saw always pulled as smooth as silk runs terrific.. the saw was not used for a few years... when I did get back to the ranch and needed to use the saw it did not pull smoothly at all..seems to me to be an abnormal amount of compression however when hot it seems ok. had plug out and no noises and pulled freely.. I figure that nothing has changed physically so carbon build-up might be the culprit.. what would you recommend to put in the gas mixture to clear the carbon?..