Dayuum my bike is running good.
This is the best I've ever gotten a china girl to run. Throttle response is excellent. 4 stroking is almost non existent. Low speed acceleration is clean, but the real powwa starts to hit about 4000 rpm @ 20 mph. After that it's like a stick of dynamite with a short fuse till over 8000 rpm (40 mph). I really don't like running it higher than 7000 though, which is 34 mph. Even that's too much for sustained cruising. The vibration level is comparable the best china girl motor I've had. Once I get the clutch out the acceleration feels like a little motorcycle. In other words there actually is some acceleration lol.
Through the whole tuning process the idle has been rock solid like a clock. It can idle all day without ever loading up. That seems to be more a feature of a speed carb than anything else.
One thing I'm still in the process of nailing down is gas mileage. I started out running rich with a 68 jet, and the needle in the leanest position. It was getting around 70 mpg maybe less, but I was running way fat oil ratio. Then I changed the jet to a 66, and I had to raise the needle one slot, because it stumbled if I snapped open the throttle. I dropped the oil ratio to 32:1. It ran well on the top end, and mid range, but 4 stroked at low throttle settings. Fuel mileage improved to 85 mpg. Today I dropped the jet to a 64. The needle clip is still in second to the top position. Oil ratio is now 40:1. This is the best yet. No 4 stroking now at any speed. I expect the fuel mileage to be around 100 mpg now, but we'll have to wait a little longer to find out. Low speed running is so smooth that running at ultra low speed might be closer to 120 mpg. As soom as I find out, you'll know.
I've done no port work, and compression is stock. Nothing at all has been done inside this motor. This is everything I've done to get it to run like this.
Flying Horse 80
MM shorty intake manifold
Speed carb
64 jet
Needle clip is second from top
High flow air filter
SBP pipe with 8" long header
40:1 Torco GP7 synthetic 2 stroke racing oil
NGK BP5HS 0.025 gap. Probably needs to a BP6HS soon
overall gearing is 4.9 mph per k rpm
This is the best I've ever gotten a china girl to run. Throttle response is excellent. 4 stroking is almost non existent. Low speed acceleration is clean, but the real powwa starts to hit about 4000 rpm @ 20 mph. After that it's like a stick of dynamite with a short fuse till over 8000 rpm (40 mph). I really don't like running it higher than 7000 though, which is 34 mph. Even that's too much for sustained cruising. The vibration level is comparable the best china girl motor I've had. Once I get the clutch out the acceleration feels like a little motorcycle. In other words there actually is some acceleration lol.
Through the whole tuning process the idle has been rock solid like a clock. It can idle all day without ever loading up. That seems to be more a feature of a speed carb than anything else.
One thing I'm still in the process of nailing down is gas mileage. I started out running rich with a 68 jet, and the needle in the leanest position. It was getting around 70 mpg maybe less, but I was running way fat oil ratio. Then I changed the jet to a 66, and I had to raise the needle one slot, because it stumbled if I snapped open the throttle. I dropped the oil ratio to 32:1. It ran well on the top end, and mid range, but 4 stroked at low throttle settings. Fuel mileage improved to 85 mpg. Today I dropped the jet to a 64. The needle clip is still in second to the top position. Oil ratio is now 40:1. This is the best yet. No 4 stroking now at any speed. I expect the fuel mileage to be around 100 mpg now, but we'll have to wait a little longer to find out. Low speed running is so smooth that running at ultra low speed might be closer to 120 mpg. As soom as I find out, you'll know.
I've done no port work, and compression is stock. Nothing at all has been done inside this motor. This is everything I've done to get it to run like this.
Flying Horse 80
MM shorty intake manifold
Speed carb
64 jet
Needle clip is second from top
High flow air filter
SBP pipe with 8" long header
40:1 Torco GP7 synthetic 2 stroke racing oil
NGK BP5HS 0.025 gap. Probably needs to a BP6HS soon
overall gearing is 4.9 mph per k rpm
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