Hi all,
Firstly thanks to the tons of posts I've spent the past 3 weeks reading up on China made 2 stroke motorized bikes.
That and watching hours of YouTube on the subject made me purchase one to use as a daily commuter.
I normally have to travel 2 hours using public transportation on a one way trip to work, before I was using my car it was 1 to 1 & 1/2 hours due to traffic. It's only a 26km (17mile) trip one way. The car was at the point where it would only make sense to repair if it had some serious sentimental value to it, so I sold it for dirt cheap and used that to buy a 2 stroke motorized bicycle pre-built.
Thanks to the above mentioned research I asked them to put on a performance head (basically a cnc head with large fins not sure if it indeed does increase compression) and a 52 tooth sprocket.
I did ask for a large frame bike but I have no space left on the mtb aliminium frame.
Basically its just like so many of the pictures here, China built 2 stoke with HT basic carb, the intake is that round black plastic one with 3 pipe type holes pointing down.
I use Castrol 2T fully synthetic oil in a red bottle. The most expensive I could find at the general hardware store.
I'm m in the break in period, 1 and bit tanks in. The first tank was at 16:1 ratio and the bike was ridden conservatively not exceeding 32kph (20mph) with varying the throttle and hitting a few hills where possible (while having to wot it to maintain speed and fear of not making it uphill) but not riding for longer that 15min at a time as per the manual.
Anyway one tank and one oil fouled plug (the standard LS.. Something thing) this was a huge blow as I happened to be at the bottom of a 2km hill that I needed to get back up to get to work...(big respect to cyclists after that)
I called the guys I bought it from they said it sound like the plug so I cleaned up the plug and added a 1lt fuel to the 1/2 tank that was at 16:1, it literally ran for 3 minutes before dying on me again. So after having done a ton of reading here I decided and the advice from the dealer to use NKG BP7HS plug, I couldn't find it anywhere near me but could get the BP6HS or the BP8HS being on the near the sea in a hot tropical area I decided to go for the BP8HS and she ran nicely.
Again taking what I've read here into account I open her up a bit today still varying the throttle but did WOT her here and there on the straights hoping that this would help the burn and set rings better. It was a 20 min run and she was quite smooth.
I noticed the black oil coming from the end of the exhaust was much thinner than before and seemed as if fuel was also passing out the exhaust as clean little cear clean rivers were noticeable within the black oil, (there is a slight leak from the top weld of the exhaust where the big part is weled on the pipe that leads to the cylinder housing. This I where I noticed what appears to be fuel passing out as well)
II did feel bad about the oil mixture being so low so I did a 25:1 mix on 1 lt of fuel and added this to the half tank. But found she was vibrating alot more and had a bit less responce on the throttle, less power up hill, less power on low revs and less top end.
Changing the plug is a nightmare, I have to lossen the chin tensioner and the engine mountings so I can tilt the motor sideways enough to get the spark out from under the frame. (motor is slanted in the frame as this is the only way it fits)
I'm really trying to avoid burning plugs as this won't be fun to change.
I've already had to replace the cheap screw on the chain tensioner and the Ubracket, the frame is rather fat and the original snapped right off when opening it as it was bent in a ohms simbol shape that weakened it. I've since added a extension bracket to the plate allowing for Ubracket not to bend.
One thing I'd like to know is how often could I expect to change the spark plug? I know this depends on a bunch of variables so let me state the here then hopefully you guys can give me advice on what oil ratio to use and cheap or cost free improvements to make.
I stay 147m (482ft) above sea level, taking laws into account I'll be driving back roads to work 31km (19mile) on a VERY mountain /hills terrain (some graidents of 35°) my clime to work is 640m above sea level (2099ft) that's a 500m climb above sea level (hense the 52tooth sprocket)
I've currently only done 56km (34miles) on the bike according to the bike computer thing I got with the bike.
What advise can you guys give me?
Firstly thanks to the tons of posts I've spent the past 3 weeks reading up on China made 2 stroke motorized bikes.
That and watching hours of YouTube on the subject made me purchase one to use as a daily commuter.

I normally have to travel 2 hours using public transportation on a one way trip to work, before I was using my car it was 1 to 1 & 1/2 hours due to traffic. It's only a 26km (17mile) trip one way. The car was at the point where it would only make sense to repair if it had some serious sentimental value to it, so I sold it for dirt cheap and used that to buy a 2 stroke motorized bicycle pre-built.
Thanks to the above mentioned research I asked them to put on a performance head (basically a cnc head with large fins not sure if it indeed does increase compression) and a 52 tooth sprocket.
I did ask for a large frame bike but I have no space left on the mtb aliminium frame.
Basically its just like so many of the pictures here, China built 2 stoke with HT basic carb, the intake is that round black plastic one with 3 pipe type holes pointing down.
I use Castrol 2T fully synthetic oil in a red bottle. The most expensive I could find at the general hardware store.
I'm m in the break in period, 1 and bit tanks in. The first tank was at 16:1 ratio and the bike was ridden conservatively not exceeding 32kph (20mph) with varying the throttle and hitting a few hills where possible (while having to wot it to maintain speed and fear of not making it uphill) but not riding for longer that 15min at a time as per the manual.
Anyway one tank and one oil fouled plug (the standard LS.. Something thing) this was a huge blow as I happened to be at the bottom of a 2km hill that I needed to get back up to get to work...(big respect to cyclists after that)
I called the guys I bought it from they said it sound like the plug so I cleaned up the plug and added a 1lt fuel to the 1/2 tank that was at 16:1, it literally ran for 3 minutes before dying on me again. So after having done a ton of reading here I decided and the advice from the dealer to use NKG BP7HS plug, I couldn't find it anywhere near me but could get the BP6HS or the BP8HS being on the near the sea in a hot tropical area I decided to go for the BP8HS and she ran nicely.
Again taking what I've read here into account I open her up a bit today still varying the throttle but did WOT her here and there on the straights hoping that this would help the burn and set rings better. It was a 20 min run and she was quite smooth.
I noticed the black oil coming from the end of the exhaust was much thinner than before and seemed as if fuel was also passing out the exhaust as clean little cear clean rivers were noticeable within the black oil, (there is a slight leak from the top weld of the exhaust where the big part is weled on the pipe that leads to the cylinder housing. This I where I noticed what appears to be fuel passing out as well)
II did feel bad about the oil mixture being so low so I did a 25:1 mix on 1 lt of fuel and added this to the half tank. But found she was vibrating alot more and had a bit less responce on the throttle, less power up hill, less power on low revs and less top end.
Changing the plug is a nightmare, I have to lossen the chin tensioner and the engine mountings so I can tilt the motor sideways enough to get the spark out from under the frame. (motor is slanted in the frame as this is the only way it fits)
I'm really trying to avoid burning plugs as this won't be fun to change.
I've already had to replace the cheap screw on the chain tensioner and the Ubracket, the frame is rather fat and the original snapped right off when opening it as it was bent in a ohms simbol shape that weakened it. I've since added a extension bracket to the plate allowing for Ubracket not to bend.
One thing I'd like to know is how often could I expect to change the spark plug? I know this depends on a bunch of variables so let me state the here then hopefully you guys can give me advice on what oil ratio to use and cheap or cost free improvements to make.
I stay 147m (482ft) above sea level, taking laws into account I'll be driving back roads to work 31km (19mile) on a VERY mountain /hills terrain (some graidents of 35°) my clime to work is 640m above sea level (2099ft) that's a 500m climb above sea level (hense the 52tooth sprocket)
I've currently only done 56km (34miles) on the bike according to the bike computer thing I got with the bike.
What advise can you guys give me?