I'm not running a Pony (yet), but you could look around the 'net and in 4x mags, and see if some of the tricks for more common carbs work.
Once I had a Jeep carb that blew an accelerator pump diaphragm just as I was heading out to meet someone at the trail head.
I took the carb off, went into the shop and grabbed an old one that was half taken apart, and had a spider and several insect carcasses inside it. I cleaned it out, and while I was putting it back together I decided to try bending the float tab a bit so it wouldn't fload the bowl as easily on angles. It worked great, that carb ran better than the new one that blew the diaphragm.
People also use vent tube extensions and other little tricks to get a carb to work better on the trail.
Good luck, and let us know what you find...I wouldn't mind installing a Pony before the summer.
Just wanted to throw in my opinion on the pony carb here. IMHO they are NOT the way to go if you are planning on doing any off-roading. I ran one for a while and it was a huge PITA when going up steep inclines. The engine would keep stalling right at the most in-opportune/dangerous point.
That said... if you are going to run one then you can try putting an extension on the vent tube, look at izook.com for info I think. Also, you may want to consider getting a U.S. intake because they are reverse to our CDN ones. That way you will stall out going downhill which should be easier to control.