Are the new 4 stroke China kits any better quality than the 2 strokes? I saw a 4 stroke kit on ebay from Boy Go Fast, that has a centrifical clutch. It looks like it could be rack mounted without too much trouble. I have been doing a bunch of repairs to my 49cc China to keep it on the road lately, and just getting a bit fed up. Between chain tensioner troubles, broken stud bolts, and a rear tire that is just a bit too wide and wants to rub on the chain a bit. I am going to try and get the spring loaded chain tensioner, and a thinner tire and give that a go for now, but the 4 stoke is looking good.