Originally Posted by Goat Herder
Simply putting a smaller jet won't do. There is atomizers,, sizes rated for different altitudes as well. I run a W7 needle here my self. It ran crappy with the stock W9 needle. With that bored out bigger bore motor it has plenty of breath enough to snort from a 21mm IMHO. My bone stock S6S save a 21mm carby is working nicely at 6000 ft here more or less.
Mebbe an extra 1000 foot or so makes that much difference? My travel is many times near the foot hills so I am sure it's at near 7000? A 258 AU Atomizer is the leanest they make. Thats what I used on the 19 and the 21mm. Until I gave atomizers etc a go it was futile.
In the beginning days about 47 mph on a china H.T.. Of course it is a matter of time till those quite running when asking a lot from them.
My first Morini s6t got it to 55mph on a straight away and ran out of road. I never tested for higher speeds after that. Because I had built that entire bike from scratch it was mandatory to properly scare myself and test it lol.
Now I just gear out to be very playful now days and top out around 40mph.
Alright Goat I'll look into the needle and atomizer. As of now i don't have much faith in that 21mm carb. I had nasty hesitation on acceleration and it ran super rich. That was after I swapped all parts from the 19mm to the 21mm (with the needle position all the way down, leanest position). Then I swapped all the parts back to the 19mm carb with the needle position all the way down and it ran great.
I don't understand how opening your carb intake diameter by 2mm would cause this problem? I'm calling Motomx.com today to see what's up.