New Carb problems By 260orbust (Read 1,013 times)

[260orbust]

OK. So I put a new carb in the old crapmobile (and by the way I'll just call it a Xyingyue 260 cause I really don't know which brand it is) cause the diaphragm fix just wouldn't work. Seems to work pretty well but as always there are problems. I have hesitation in the 5 to 10 mph range, it will back fire too if I hold it there. Twist the throttle a bit more and problem solved! Best way I can describe it is like the engine is not getting enough fuel. I've readjusted the carb but no change at all.

The next problem is speed. It now goes faster than I've EVER seen it go.... When there is no wind that is! I went to work one night and the wind was blowing pretty good and I had to hold it wide open just to stay at 55 mph. The damn thing just wouldn't pull but if the wind let up even a little speed began increasing. Also, I used 3/4 of a tank just getting to work but on the way home the wind had died down and I was able to cruise @ 55 mph and made it back on 1/4 of a tank. Surely there is something wrong here right? Wind cannot affect these god awful things that much can it? All the hoses (fuel & vac) have been changed and I've FINALLY got the entire intake system to stay put. I checked the intake manifold and it's not cracked, so what is the problem now?

[speedracer]

IMO it depends on high the winds were. I know when we have high wind warnings I'm lucky to keep the scoot in the right lane. If you are into a strong headwind your body will slow down the scoot. I know I can feel the scoot slow down and speed up when the wind hits me head on and then dies down.

Back fire might be from the A/F screw. You are getting too much gas and not enough air.

[260orbust]

So basically when it comes to the wind issue what your saying is ,"There ain't nuttin you can do about that jack!" Right? LOL

[Alleyoop]

There is JACK crap you can do about the wind, it will always slow down your scoot and suck up more gas.

Now if the wind is behind you and pushing you, then look out the scoot will fly with less throttle.
Alleyoop

[scooteraddict]

From what I read, you have a lack of power when you first crack the throttle. If this is true, it's due to running lean in the first 1/8th range of the throttle.

I too had this problem and found that I had to go up one or two (can't remember) pilot jet sizes and raise the main jet needle up. By moving the needle up, I mean that you must dismantal the diaphram and remove the needle. Take the clip and put is the lowest setting away from the top, put everything together and reinstall the diaphram.

This was hit or miss effort for me but I found the right combination to get rid of the hesitation (lack of power) at the cracking of the throttle.

I know for a fact that this IS the problem you are experiencing because I had used a O2 sensor and wide band meter to watch my fuel ratio mixtures.

Now if you are brave, use the old carb and install the diaphram from the new one into it if only it was running right. If you are still having a problem make sure you match the main needle jet with the old one.

good luck.

[260orbust]

I thought about doing that when I first got the carb but didn't! (Doh!) Maybe I'll try it over the weekend.