Well I have finally got my ZBOX 80 (66cc) going good/fast. The problem I was having after doing all the std. mods was it was still crapping out at WOT. My problem was that I did too much work too quick and all at the same time. So to fix my problem I ordered another NT carb and bolted it on and straight away it went heaps better.
Things I did to the original carb was:
*upsize the jet to #76
*Match ported the manifold to the cyclinder
*Opened up the size of the intake port on the carb by a few mm.
*Sanded down the needle on the bottom 1/3 (that was my big mistake as it tured out)
Also I have cut off the pipe on the end cap of the muffler and screwed in a 3/4" brass socket with a barb on it and also match poted the exhuast manifold. I also run the NGK B*6** plug with a good lead and cap ans run at 1:30 semi syn. Motorex racing oil.
So when I put the std carb back on it ran better. Then I moved the needle clip up to the top slot. It ran even better with no smoke at idle. Then I changed from the #70 jet to the #76 jet and it went even better. Then I put my sports air filter on.............did not make that much diff.
But the good news is I hit 48km/h (30mph) with no trouble at all. So the only thing I dont have on this new carb is the sanded down needle. It goes way better and smoother now.
Steve
Things I did to the original carb was:
*upsize the jet to #76
*Match ported the manifold to the cyclinder
*Opened up the size of the intake port on the carb by a few mm.
*Sanded down the needle on the bottom 1/3 (that was my big mistake as it tured out)
Also I have cut off the pipe on the end cap of the muffler and screwed in a 3/4" brass socket with a barb on it and also match poted the exhuast manifold. I also run the NGK B*6** plug with a good lead and cap ans run at 1:30 semi syn. Motorex racing oil.
So when I put the std carb back on it ran better. Then I moved the needle clip up to the top slot. It ran even better with no smoke at idle. Then I changed from the #70 jet to the #76 jet and it went even better. Then I put my sports air filter on.............did not make that much diff.
But the good news is I hit 48km/h (30mph) with no trouble at all. So the only thing I dont have on this new carb is the sanded down needle. It goes way better and smoother now.
Steve