Originally Posted by
flyinwalenda
Mine had the clicking early-on after 2 gallons was run through it. The clicking got louder and I removed the backplate (after Horizon's approval)and saw a deformation in the crank pin. Horizon rebuilt it and now I'm almost through the second gallon after the rebuild (over 4 gallons total) and so far so good. I used dino oil for break-in and Klotz afterward.
When you sent your engine in, did you send the muffler and ignition module as well? I filled out the rma on the Horizon site, but it did not specify. I emailed them the same question, but they have not answered yet.