Why does it take so long for my bike to speed up?

Goergedave

Member
Oct 23, 2015
51
7
8
Texas
It spits and sputters at the low end and takes forever to reach wide open throttle but once it does it cruises at 35mph without issue. I don't stay there because my engine is still new. It's a stock 66CC motorized bicycle with stock settings. It wasn't doing this initially but now that I've traveled maybe 50 miles with the same gas it's starting to bog down for some reason. I haven't changed the ratio from 16:1 either. My spark plug is not dirty at all. It isn't dirty white, happy brown or sad black.
 
Last edited:

LR Jerry

Well-Known Member
Dec 19, 2011
1,211
117
63
58
Rockwood, TN
Check all bolts and make sure everything is tight. Check fuel and air filters. Check your exhaust for any blockage. Once my bike set up for a couple of months and dirt dobbers built a nest in the exhaust lol
 

indian22

Well-Known Member
Dec 31, 2014
3,855
4,637
113
Oklahoma
Your motor is new and needs to break in slowly. Forcing it to top speed is very hard on new motors even briefly. Run a couple of tanks of the break in mix first. The motor will live a lot longer. Performance should improve as the motor loosens up and the switch to thinner mix after break in will make a noticeable difference. Also fine tuning the carb after break in is good as well.

A lot of good motors are ruined by poor riding decisions.

Rick C.
 

Goergedave

Member
Oct 23, 2015
51
7
8
Texas
The bike wasn't operating the way it should and I am still not entirely sure what was the issue. With my gas and oil at a 16:1 ration I do know there will be reduced power until everything get's lubed, tight and happy. These are a few of the possible fixes I read about regarding the engine getting bogged down and not accelerating properly. I went ahead and tried them all. Sledgehammer met fly. I adjusted the float arms a wee bit. While that doesn't lean out the gas it does stop the gas from filling the bowl too much if I'm not mistaken. I leaned out the gas by adjusting the needle clip one line up. I changed out my filter and gas lines because I have extra. Finally... I can't remember the last thing? Oh, I also changed out the petcock. It's back to accelerating the way it should.

In the end it could have been none of those and I simply had a little debris where it shouldn't be. I'll be checking on my spark plug to make sure those moves don't color it white.
 
  • Like
Reactions: LR Jerry

LR Jerry

Well-Known Member
Dec 19, 2011
1,211
117
63
58
Rockwood, TN
If debris becomes a problem again, do a good Sea Foam flushing. This stuff can do a really great job at cleaning an engine out.
 
  • Like
Reactions: FOG