Tommypaul, welcome! Lets try to answer your questions. I lifted my G1 by making my own Pachanga lift but welding is def required. Whatever lift you choose talk to the manufacturer about wheel/tire sizes. I'm not sure that you could go greater than 21s with a 4" lift. G1s do not idle, however if the black white wire from the engine is disconnected it will idle. the downside to this is if a kid gets near your cart while its idling the cart with the kid could take an unexpected ride. Not a good idea! The jerking part could be carb adjustment or clutch problems. Check the belt, sheaves, springs etc for proper tolerance and specs. This info can be gotten from a G1 service/repair manual available for download on e-bay @ $11. As far as wheel tire combos the best deal I found was thru Trademark Carts who is a site sponsor. You can check out my build @ Another G1 Rebuild! in the lifted cart section, it may answer some questions for you. All the Yamaha builds there may be of help. Good luck and get some pics posted
