Fuel Mixture Low low end power

[MinimumVK]

Hi! I rode about 10km on my chinese yd100 motor and the main thing that is bothering me is that it has low power when pulling up hills bellow 80% throttle (on a flat it 4 strokes alot). Full throttle it pulls really nice up hill and on flat ground. Trying to spare it as much as possible because its still on its first tank. The needle C clip is on the middle (3rd) position. Should i maybe move it 1 up or is it too lean? Spark plug looks a bit black but nothing too much

 

[DAMIEN1307]

Should i maybe move it 1 up or is it too lean?

Go ahead and move that C clip up one more notch and try it out for a little ride again, if its not improved or gets worse, you can always place it back in the middle again...lol.

Good move replacing that junk Chinese spark plug with an NGK by the way.

 

[Gordy]

Another thing is if the engine is fourstroking you could have too large a gap in the magneto

 

[DAMIEN1307]

Just be sure to only try just one change at a time so you know what is actually working or not working out for you...That helps narrow problems down by doing only one change at a time.

 

[MinimumVK]

I adjusted the C clip on the needle so that it is on the 2nd position from the needle side up. The bike seems to pull a little bit better at any given throttle range (still 4 strokes when not on full throttle). I will make a few trips and then read the plug.
As for the magneto i adjusted it so that the gap is the same on the top and bottom. It seems a bit too large of a gap but you guys said that it should be the same and not lets say more on the bottom and less at the top.
Overall im happy the way it runs now just needs some fine tuning and breaking in.

EDIT: Forgot to mention that when the c clip was one notch above the middle one it bogged and had no power (0-80% throttle) so leaner wasnt the way to go.

 

[MinimumVK]

UPDATE: I made my first 100km with the bike.
I moved the c clip on the middle position and left it like that since it seems to run happy there. Overall im happy with the performance.
Also suprised how none of the bolts loosen (i read that this is a big problem on these bikes)

 

[Gordy]

UPDATE: I made my first 100km with the bike.
I moved the c clip on the middle position and left it like that since it seems to run happy there. Overall im happy with the performance.
Also suprised how none of the bolts loosen (i read that this is a big problem on these bikes)

I've only ever had that issue with my exhaust studs

 

[darwin]

I've only ever had that issue with my exhaust studs

If possible give the muffler some added support to the frame.

 

[MinimumVK]

I think i will make a 50cc pocket bike exhaust fit. It would definitely be better then the stock one. I would just need to cut the flange and re weld it at the right angle. The flange is the same as the stock exhaust

 

[MinimumVK]

So i made the pocket bike exhaust work but i wont be using it for now because of 2 things: there is a bit too much noise for it to be ridden on public road and it starts 4 stroking like crazy above 35km/h. BUT the torque is about 30% better then the stock exhaust so it would be good if i would install a smaller sprocket or for a trail bike. Now could i improve the exhaust i made in any way? I would say it is either too long of a header or that there are too many bends in it (it has a 45° flange coming right from the head)


Moderators Note:
I manipulated that 1st pic to a pic that can be seen somewhat easier, the second pic...DAMIEN