Yikes!! I discovered a huge chain issue: After ordering the #41 chain
and laying it alongside the #415 chain that came with my 4 stroke ebay kit, the
415 chain links have a different length or pitch than than the 41 chain links.
After 4.5 feet, the 41 chain is longer by about 3/8 of an inch, maybe 1/2 inch.
The link pitch or length on both chains is supposed to be 1/2 inch, which means
that the 415 chain that came with the kit is out of spec, and this is the cause of the 415
chain failure to operate smoothly and wanting to jump the sprockets. No amount of
filing on the sprockets can fix the problem it causes.