Good morning Ray. A few answers to your questions, first, my front belt wore enough to cause it to slip when trying to start a cold engine. I moved the engine forward to tighten belt but with it this tight, it does not utilize all of the pullies surface at higher rpm, so I lose on top end. If that makes any sense to ya. The belt # I gave you was a NAPA belt,but same # as Gates. I'm still running the OEM 16mm carb. Here in Ft.collins, Co, I'm about 5400+ft. of altitude. I'm presently running a #80 stock jet, with needle clip in second notch from top. Got a brownish grey plug and engine purrs with these settings. I have adjusted valves, replaces compression release with 10mm bolt per Quentions instructions. Just been enjoying the ride here lately. In the very near future, plan to put engine on the bench. Plans include, cylinder porting and decking, cureing. Shaveing head. Haven't decided on how much so far. Mostly depends on type of head gasket I use. Hopefully will be able to cut one from copper sheet that will fit the compression chamber closely. Would like to find a 22mm carb also, but this 16mm carb is really a sweet unit. A ne5 head would be a nice find too. I'm not looking for a hotrod, just a nice dependable ride my grand children will get a chance to ride someday. The whizzer experiance should always be shared and enjoyed. After the tear-down, I'll give Quenton a buzz and make a game plan from there. I still need a tach also if you come across one.
Also, a quick note on jetting. I build quite a few bikes, quadricycles and even a small jeep with bike parts, for my granddaughter. I use the GT50 pocket rocket engine such as the one Duane sells @ THATSDAX, and they are picky about jetting. Rather than trying to find jets, I solder up jet opening and drill new jet hole. I enlarge hole until happy with the way they run and spark plug has the color I'm looking for. Skill level is moderate if confidence level is above average. Good luck, have questions, let me know. Later gator_____ Russell