The pingrey tip is rough around the edges, but i used high temp sealant to make the tip airtight around my can. I also cut the inside of the tip flush. I had my carb bored out 1.5 mm for $50.00 and drilled four 1 inch holes in a second airbox lid. I keep the original lid with no holes for rain and mud or when we go to silver lake sand dunes. I took header wrap you can get from a auto parts store and wrapped my pipes with it up to the silincer. This trick keeps the pipes very hot which in turn means more velocity of the exhaust gases.(also everyone looks at it and says wow who makes those I laugh and say N.A.S.A) I run a 180 main jet and second from the top needle. The machine runs very well with these inexpensive mods. Future cheap mods will be a small car engine oil cooler, and a fan that will run all the time on the radiator. What alot of people tend to forget is that stock motors are in a very soft state of tune when deliverd to the mass public I.E. fat jetting, restricted airbox, restrictive exhaust. But with a little wrenching most any motor can see a huge increase in power.