first run out. wont rev up all the way!! little power.

R

radrob

New Member
spent the last 10 hours working on my first motorized bike 80cc kit.
First shot out wont rev up all the way.sputters at full throttle. runs a little better if you back it off a bit.adjusted idle screw dosent make a difference. When i got the kit the plug was damaged. I instaled a ngk b5hs. It has a fuel filter and i made sure the tank was clean. gas is fresh 16 to 1 mix.
It idles fine just dosnt want to rev up all the way.
not sure what to look for . any hep will be apriciated.
rob:-||
 
Run a couple tanks through it.. these engines take a couple tanks to break in. Until then they are a big sluggish. Once its broken in, you'll feel a lot more power.
 
right on radrob glad to see that you didnt install the original plug that it came with. They've been known to fail during operation and cause severe damage. The 16:1 ratio is twice as much as i use (32:1) and it may give you problems, or at least symptoms. There are a few things that may help with your WOT probs, one thing that since your dealing w/ factory jetting.,.,make sure that the C clip on the needle is in the #1 slot. Which is the furthest slot from the point of the needle. Rejetting is your other option,.,since these carbs cannot be adjusted, other than idle. good luck
 
Hey radrob, I would also use some carb cleaner to check for intake leaks. An intake leak will make one run weird. Also make sure your choke is in the correct position. ( choke lever up=choke on) Just keep checking back here, as i am sure you will get plenty of help from other members. And welcome to the forum.
 
First time out, it starts and idles OK? Pretty good!!!

The fact that the idle screw makes no difference and it has a hard time reving tells me you may indeed have an air leak (common) as the others say.
 
I put some sealent on the intake last night. Im going to get a fresh batch of gas a little leaner.
and bomb it for awhile.
 
Run it @ 24/1 .
You may have an overly rich condition if it sputters (staccato sound) at WOT. A lean condition would cause it to sag but still run with a buzz instead of the four cycle staccato.

Look at your plug White/grey = too lean. Black/oily = too rich.
 
BTW- if you are running too rich (fuel to air) then running 24:1 will make it worse. Then you will need to move the clip up a notch, or re-jet.

More oil in the mix = leaner gas to air ratio. Less oil = richer gas to air ratio.
 
the plug was a bit wet. replaced it and put some 20 to 1 gas. Ran a little better this morning. took it for a few rides throughout the day and it semes to run a little better each time. I put 35 miles runing around my neighborhood. got it up to 25 top speed. The first couple miles it ran terrable.I think it going to be ok. If its not raining tomarow im going to ride it to work. Wish me luck..shft.
.shft.
 
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oh yea here is a pic of my bike
 

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I pulled the crome cap off and cut the end open so it would slide in farther. the bike hade twist grips for the derailers. I changed it over to levers on the gooseneck. and am using the left side twist for the the clutch. really need to switch bars to something up higher.
 
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