Hi All,

I apologize if I'm putting this in wrong forum.

I have a 2006 urban touring 150cc ex chinese scooter. I believe it has a gy6 engine.

It will not idle, runs very rough, but once you get it moving about 20mph it smooths out and purrs.. - miss-firing at low speeds

Recently purchased from someone who let it sit in their Garage a year or so without driving it....covered in dust. put new battery in, started right up, ran great, but....then on the way home...something changed and had to rev it up just a little to keep it running at stops, but not much...

it was near empty so I filled the gas tank and drove it 20 miles home, did 55 no prob. no missfiring..

Next day drive belt busted. I guess it was dry rotted.
Replaced drive belt then noticed fuel leak below carb. bowl.
Replaced cracked fuel line.
wouldn't start....
over anxious buddy sprayed non-ether based starting fluid in breather despite my objections...
It Fired it up, smoking...miss firing...and sounding like it's was knocking
smoking stopped...still missfiring and sounding like it's knocking at low speed, runs really smooth at high speed.
looked for vacuum leaks, sprayed carb cleaner all around carb and lines got no change in engine speed.

Did my buddy damage my engine?
what next?
Any advice would be appreciated.

thanks.

 

Welcome to the forum whosgotmyback!

You found the perfect place for your question..

Since it seems to start easy enough Id say your carb is dirty and or gummed up and needs to be cleaned...

Id change the oil...any 10-40wt oil will do...i use Valvoline in mine.

 

Hi mywifesquad,

I cleaned the carb, the jets, everything, adjusted the float, installed new fuel lines, changed the oil...Warmed it up, adjusted fuel mixture....fuel is flowing nicely through fuel filter.

It's somewhat better now. It's not smoking or knocking anymore but it still idles rough, takes off rough & slow - stuttering....but once you get to about 10mph it starts to smooth out and continues getting smother & increasing the rate of acceleration as it gets going faster.

Sprayed around carb. & all vacuum lines with carb cleaner and it made no difference.

I'm thinking the next thing to do is to adjust the valves? But don't know what to set them at. I see different setting all over the forums on the net.

BTW, one other very odd thing, and I didn't notice this until after I bought the scooter (cannot believe I missed it-what a brain fart I must have had)...the tachometer is reading way to high, even at what is clearly a low idle speed, it's in the 4-5k range, then when I'm hitting about 30mph it starts to go past the red line and completely off the scale. It couldn't possibly be revving to 12-14k - or it would have blown up by now. I have no idea what's causing this.

 

Also...turning the fuel mixture screw almost all the way in gives highest RPM.

 

Valves should be set at .004 with the engine stone cold.. Turning the fuel screw in limits fuel... leaning things out which would cause a higher but sort of floaty idle... too far out and it will bog..

No idea on the tach..