You can get the billet thrust washers from Mitch in the store at the top of the page. They go on the piston pin. The stock one's are stepped steel and like to break. It will typically cause a lot of engine damage. The aluminum one's don't do near as much damage. To run them you will need a 99 suzuki rm250 wrist pin bearing, it is narrower and works with the billet washers. Either a suzuki dealer or ebay can get them for cheap. Harbor freight has a cheap leakdown tester, get one. As for gas I would at least run premium. 100LL or race gas is a lot more consistent to jet. pump gas can contain up to 10% ethanol, but you don't know it might be 1% or 10%. I use Maxima 927 oil. Get a copy of the factory suzuki manuel it is helpful. Also consider having the squish cut properly on the head before you put it together. I like cometic gaskets, the cometic afm's are great base gaskets.