YD-100

[Dylan57]

I got this new YD-100, 26’ wheels, 36t sprocket, currently 28:1, standard NT carb (not stock speed carb), about 100 miles on the engine and have only recently starting giving her more juice at times. With the 44t, had great low end torque, but it barely went over 20mph, been jetting and adjusting the needles over and over, but the bike just non stop four strokes and stops accelerating when I hit around 22 mph on 44t, and about 30 mph on the 36t. Only 4 stroking issues up before then is, only sometimes when I try to cruise at a consistent speed. If I twist the throttle a little bit back and fourth sometimes I can get a few extra mph. I assume it’s just because it’s still breaking in, but if that’s not the case, any help would be appreciated.

 

[Wrench]

Fuel air mix too rich

 

[GW's Motorized]

The yd100 won't be much faster than the regular CGs. They have more bottom end, but the internal geometry isn't good enough for them to have more top end

 

[Dylan57]

Fuel air mix too rich

All leaning it out did was make me lose power and never even be able to reach the point where it would start four stroking.

 

[Amwicr]

Turn off the choke

 

[Chainlube]

The YD100 is a dog, if you get 25mph be very happy. Not always "bigger is better" is true. Zeda triple 40 is a good beginner kit.

 

[Dylan57]

The YD100 is a dog, if you get 25mph be very happy. Not always "bigger is better" is true. Zeda triple 40 is a good beginner kit.

I should’ve emphasized my question. Is the nonstop four stroking, and inability to accelerate any further, I’m experiencing once I hit around 22, no matter if I’m going downhill, or on a straight surface, normal when hitting top speed, Or is it something else? I’ve tried every clip position, and tried #62, 65, and 68 jets besides the original, going either way only made me lose power or cause more four stroking. I get that a 44t sprocket on a $160 engine isn’t gonna get me going 30mph, that’s why I got the 36t, I just feel like it can go more but something is stopping it.

 

[mony0_3]

Did you do any porting? Mine came alive after I opened up the intake and raised the exhaust ports. Plenty of low end torque and 36mph top speed with 44T sprocket.

 

[Dylan57]

Did you do any porting? Mine came alive after I opened up the intake and raised the exhaust ports. Plenty of low end torque and 36mph top speed with 44T sprocket.

Not yet, I figured I’d wait until 200 miles to do anything like that. Before you ported, what speeds were you looking at, and how would it behave when you hit those top speeds?

 

[ImpulseRocket]

I should’ve emphasized my question. Is the nonstop four stroking, and inability to accelerate any further, I’m experiencing once I hit around 22, no matter if I’m going downhill, or on a straight surface, normal when hitting top speed, Or is it something else? I’ve tried every clip position, and tried #62, 65, and 68 jets besides the original, going either way only made me lose power or cause more four stroking. I get that a 44t sprocket on a $160 engine isn’t gonna get me going 30mph, that’s why I got the 36t, I just feel like it can go more but something is stopping it.

Don't forget that the ignition plays a role in how well an engine runs, and often reveals it's weakness or other issues under load and at high RPM. Try an NGK plug from the parts store Part 3922 aka BR6HS. The plugs these engines come with are very iffy quality and often cause a lot of running issues. Your top speeds in each gear also indicate the engine itself is having problems going above about 5500rpm (22mph with a 44t and about 30 with a 36t) also making me believe your issue is ignition related more than fuel.

It may also be worth looking at your carbs float height and adjusting it as necessary. There should be a sticky in this section covering how to check and set the float height.