I have a ZOOMBIKE kit 66cc slant head on my mountainbike. The kit has around 300-500miles on it.
Engine was run in properly according to user manual (speed and fuel mix). Most of the kit is stock. The exhaust pipe felt into parts and was replaced with a expansion chamber. Furthermore I put a 36T sprocket. The connections carburetor/engine and engine/pipe were cleaned, the gaskets adjusted and in addition everything with heat resistant silicone sealed. Idle is very smooth.
I had lot's of problems with this kit but customer service was great, they always sent the spare parts really fast. Unfortunately I still have two problems:
1) The clutch is still slipping, especially uphills. I ensured the clutch releases fully. I cleaned up everything and made the surface of the clutch disc a bit more raw. I increased the pretension a bit. All this helped a bit, but the clutch is still a bit slipping uphills. Did anybody replace the clutch spring to increase the pressure between the clutch disc and the pads? If yes did it help and where can I get a suitable spring?
2) The bike doesn't go faster than 30mph (GPS measured). It goes very powerful up to 30mph but starts stalling at 30mph. All connections are good and sealed, never drove in rain (California). The generator/magneto stopped working a week ago and was replaced, still the same defect. I removed the (stock-)airfilter and drove without airfilter for a test run - no difference. It has still the stock spark plug. The choke lever vibrated of the carburetor. I removed it completely and sealed the hole. The choke was never working, the engine wouldn't start with pulled choke.
For me the strange thing is that it goes up to 30mph very powerful but then the engine stalls like somebody is push's the kill button as long as it's over 30mph. It happens exactly at 30mph, never more or less. With a 36T sprocket it should go faster.
Hope some of you will come up with ideas how to solve these issues.
Engine was run in properly according to user manual (speed and fuel mix). Most of the kit is stock. The exhaust pipe felt into parts and was replaced with a expansion chamber. Furthermore I put a 36T sprocket. The connections carburetor/engine and engine/pipe were cleaned, the gaskets adjusted and in addition everything with heat resistant silicone sealed. Idle is very smooth.
I had lot's of problems with this kit but customer service was great, they always sent the spare parts really fast. Unfortunately I still have two problems:
1) The clutch is still slipping, especially uphills. I ensured the clutch releases fully. I cleaned up everything and made the surface of the clutch disc a bit more raw. I increased the pretension a bit. All this helped a bit, but the clutch is still a bit slipping uphills. Did anybody replace the clutch spring to increase the pressure between the clutch disc and the pads? If yes did it help and where can I get a suitable spring?
2) The bike doesn't go faster than 30mph (GPS measured). It goes very powerful up to 30mph but starts stalling at 30mph. All connections are good and sealed, never drove in rain (California). The generator/magneto stopped working a week ago and was replaced, still the same defect. I removed the (stock-)airfilter and drove without airfilter for a test run - no difference. It has still the stock spark plug. The choke lever vibrated of the carburetor. I removed it completely and sealed the hole. The choke was never working, the engine wouldn't start with pulled choke.
For me the strange thing is that it goes up to 30mph very powerful but then the engine stalls like somebody is push's the kill button as long as it's over 30mph. It happens exactly at 30mph, never more or less. With a 36T sprocket it should go faster.
Hope some of you will come up with ideas how to solve these issues.
