Bike not running.

Firstbuild408

New Member
Joined
Nov 18, 2019
Messages
16
So I was riding full throttle on my new Chinese 2 stroke engine. I know dumb. Hasn’t had even 50 miles on it yet and now it does not run. It started when I changed the spark plug to an NGK B6HS which made is run better but the idle was way to high so I moved the c clip in the carburetor pin to full lean. I also moved the idle screw which helped a lot. So the problem I had was the engine was running way hotter than before and it got so hot it smoked but I didn’t stop. Again I know dumb. So the bike slows from 30mph to 10mph full throttle then dies. When I try to start it up again it makes a clicking noise like it’s not seized but something might have broken?
I have the motoos 80cc motorized 2 stroke kit from amazon. If anyone can give me advice to what to test it what might have happened would be appreciated.
 


Akutey

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Dec 10, 2018
Messages
170
I would't worry about WOT after the first few miles. I'v been told to do it to help the break in time and have never had issues.
It's more about wearing in the piston rings.

Don't worry about the idle, it will not idle until broken in and that will take over a good 200 miles. During that time you will notice a increase in power and it will idle.

Move you clip down to the second lowest or the lowest if your not near sea level. You are way too lean and it could cause damage.
Keeping it rich will help break in and keeping it cool.

The sudden loss of speed is common with a China Girl and usually the clicking noise is the aluminum fins cooling down on the cylinder and contracting due to rapid heat expansion.
 

Greg58

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Joined
Jun 3, 2012
Messages
442
It sounds like you already have damage to the rings or the plating has started flaking off the cylinder, if it's a removable head design rotate the engine to the bottom of the stroke and remove the head and check the cylinder wall. Torque the head bolts to 12 ft lbs.
 

Greg58

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Jun 3, 2012
Messages
442
I just saw your engine and it's a one piece head and cylinder, the only way to check for damage is to remove the cylinder.
 

GreasyChris

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Jan 3, 2019
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788
Sounds like you broke something internally. You'll have to tear it apart and see what's broken. I'm suspecting a new engine in your future
 

Firstbuild408

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Nov 18, 2019
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16
I’ll check it today if possible. It is a one piece head I’ve tried rotating the crank but it get stuck about halfway down. I’ll take it apart and send pictures soon. If it is the cyclinder and Piston is there any aftermarket parts for these engines?
 

GreasyChris

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Jan 3, 2019
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788
I haven't seen any parts for those on the market but I'm sure the bottom end is the same so you could use a regular cylinder and head. You just need top figure out if you have a low hole or high hole piston.
 

Firstbuild408

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Nov 18, 2019
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16
If I need a type A piston (low) or a type B piston (high). How do I know if it would fit? I’ve seen some cylinders being 30mm and 40mm or of that the diameter of cylinder of where the piston will sit? Also the heads is that the same situation?
 

Firstbuild408

New Member
Joined
Nov 18, 2019
Messages
16
If I need a type A piston (low) or a type B piston (high). How do I know if it would fit? I’ve seen some cylinders being 30mm and 40mm or of that the diameter of cylinder of where the piston will sit? Also the heads is that the same situation?
 

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Greg58

Active Member
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Jun 3, 2012
Messages
442
You’ll have to measure the piston pin height from the bottom of the skirt to the top of the pin, 15/16 is type A. The 30mm is the width of the intake port studs, measure yours and match it. You’ll need a stud kit also since yours uses bolts at the bottom, get the same size stud kit.
 
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