I have also had outstanding results with Startron. There are diesel and gas versions. I haven't looked at the difference, always used the diesel version but note that the gas version is available locally in parts stores and small engine shops. Diesel version is available on line.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.