help, im getting too much air By budthatsmyrealname (Read 1,960 times)

[budthatsmyrealname]

i have 100cc bore on my qmb139. the kit came with a keihin carb (unsure of the size but was included in the kit)

heres what i did, i seen a video on someone boring out the intake of the carb and polishing it. i said to myself wow what a great idea. So i did that, didnt hit any of the brass pieces and i think i did a good job. now it wont start. itll crank, and kick once and continue cranking and kick once. so i put my hand over the intake (basically choking it) and it started right up. when i throttle it itll die out and ill let go of the throttle and itll idle again. i put the stock carb back on, and it runs around the street just fine.

so basically im getting too much air, i adjusted the needle height, the air fuel ratio and its not helping any. any one can help me how to less air? or do i need more fuel? or is the carb wasted? thanks.

[jct842]

You may need a new carb. The tight place in carb is to make vacuum, a venturi I think is what it is called. That vacuum is what sucks the gas thru the jets to become gas mist. I would try the old carb first.

[cyborg]

The carb just may be too big,,, also there may be something wrong with the new carb,,, you will not be the first person to have a bad part right out of the box,,,, run the old carb till we can sort out the new one or return it and have the vendor send you another carb

[jct842]

I believe what the original poster did was ruin the carb by "boring it out"