Maybe not fuel related issue? By twowheeler (Read 436 times)

[twowheeler]

For months now I cant get rid of the "off the line" momentary sputter. Tried 2 different carbs, different jets, different needle positions but still there. It only happens when i come to a stop for more than 10 seconds. Whether its 80 out or 30 it doesnt matter. When i go to take off it sputters for a moment then revs right up. Makes me think its not the carb since different carbs and jets dont help.

[Alleyoop]

It is your carb how do you start off easy on the throttle or crank on the throttle/
Alleyoop

[twowheeler]

Never paid attention... Maybe I can raise the idle higher to compensate.

[kz1000st]

I would check your intake manifold. If a slight crack is present you might have an off the line lean stumble.

[Alleyoop]

Yes it could be idling to low as well.
But you did not answer the question HOW do you start off easy on the throttle or a hard hit.
Alleyoop

[twowheeler]

Ireally never paid attentiontp how much i give it. Ill try both ways tomorrow.

As for the possible intake crack, why wouldn't that effect performance all the time?

[Alleyoop]

I think you need to adjust the FUEL RATIO MIXTURE a little it needs a little tweaking so it won't stumble starting off. Now it could be TO MUCH FUEL or NOT ENOUGH so wherever it is set give the Fuel Ratio Screw 1/4 turn COUNTER CLOCKWISE try richen it up a little first if it gets worse then LEAN it out 1/4 turns at a time.
Alleyoop

[kz1000st]

Jan 15, 2014 19:01:16 GMT -6 twowheeler said:

Ireally never paid attentiontp how much i give it. Ill try both ways tomorrow.

As for the possible intake crack, why wouldn't that effect performance all the time?

Because a slightly lean mixture is not always a terrible thing once a scooter is rolling. I knew mine had a problem because I learned French in High School. You see the word carburetor in French means "DON'T TOUCH". I left all my idle adjustments alone out of the box and when the scooter started lean surging and stalling at idle even though I had adjusted the valves, I knew something was up. Cracked intake manifold.

Also if you've had the crack or leak for awhile you may not have noticed the change, it's very subtle. Mine ran fine at all other throttle settings except idle and three quarters. Then it surged or stalled.

[twowheeler]

If i remember on my Tao Tao I had the same issue when i replaced the carb. The new carb had a 33 pilot and i transplanted the stock carbs 30 pilot and the symptom went away. I found a 30 pilot on partsforscooters and will try it. It seems to be a rich stumble and not a clean lean stumble.

BTW I tried taking off soft and hard, no difference.

[Alleyoop]

Just try leaning it out then.
Alleyoop