Weldangrind's New Lifan GY5

[Weldangrind]

I bought a new Honda spark arrestor for Lifanda, since the part that came with the muffler I bought on eBay is a little small. It can't be easily modified, because it necks down inside and outside the spark arrestor screen. I just received a spark arrestor for a '96 XR250R, since I knew the design and size. I also knew that it wouldn't be a bolt-on deal, but a little Dremel work solved some minor bolt hole misalignment. Here's before and after.





That required rejetting, so I removed the carb and unscrewed the 22.5 slow jet and 110 main jet. I checked with the numbered bits I have, and a 110 jet falls right between a #57 (0.043") and a #56 (0.046"). In Metric (which is what the Mikuni jet system is based on), a #57 is about 1.09 and a #56 is about 1.17. It struck me as too much of a jump to go straight to 1.17, so I used a 112.5 that I had in stock. I also installed a new 27.5 that I bought online.

If I have to drill out the jet further, I'll use this drill and bit set.