When you're adding a UNI (or in my case an MRP)... what's the purpose of adding the chrome drain pipe between the carb and the filter? Is it just to connect the two, or is there actually a performance issue here?

I used a short section of the old snorkel box hose to connect my new filter to the carb, but did not use a 6" section of pipe or tubing as a spacer in between like some have. Is it needed?

I'm trouble-shooting a bad idle / throttle response issue I'm having with my 150 talon. Seems to run alright at 1/2 to full throttle though.

the drain pipe is a way to connect the carb and the filter. it also allows more air in due to its dia. also its smooth on the inside so the air gets a smooth run at the carb and is not tumbleing

think of the air moluclues as a bunch of marbles bouncing around inside the filter, all trying to go into the opening of the carb at the same time. like a unrulely crowd, all trying to go through a door at once. Line them up , they file through fast and efficiently. thats what the tube does. the trick is to get the tube the right length. Too short : there isn't enough time and space to get the line formed. Too long: the line spaces out to much, then runs out of momentum and doesn't reach the end fast enough. thats why those long snorkles don't work so well. A 6" pipe seems to work good. Idealy a straight pipe that is the same diameter as the filter outlet that tapers down to the carb inlet diameter is best.

Mike, try the 6 inch pipe and see if that works. If you need to have your air intake snorkled then you can start that project knowing your motor runs good with the standard 6 inch intake and you then just have to find the right combination of material and jets to make your buggy run correctly. I had my old gx150 snorkled with a molded radiator hose (so it was smooth inside, not corrigated), braced properly to a round steel stock that was welded to the swingarm/engine cradle, and the UNI was directly attached to the end of the radiator hose. If the electrics had been completely waterproofed I think the engine would have run completely submurged. I have to admit, I got lucky and the carb was not hard to tune, but I'm sure that had alot to do with the hose I was running for my snorkel.

I should have trusted my own instincts and the BN advice to begin with!

I bought the chrome drainpipe and a rubber coupler, cut a section of the old airbox hose as another coupler and got it hooked up with clamps last night. The difference was immediate, and it looks great. Used zip ties to keep it stable. When I started her up and hit the gas, there was definitely a little more power and a smoother sound. Once the tranny engaged I stomped on the brakes and gave it throttle... ha ha ha... the tires were spinning and dust was flying!! THAT's more like it.

That got me thinkin'... if I have even BETTER air flow now, do you think that will lean it up a bit? Before this, the plug was still pretty black (125 main jet, with a not-so-gutted exhaust at 4500' elevation)

it should be about right now

Glad you got it running good

Glad it worked for you. But usually IMO if idle and off idle is poor but runs good after say 25 percent throttle that usually shows a pilot jet is too small. My bro runs a filter right off the carb and the machine rocks. Has anyone tried pvc pipe yet? If you can find the same inside diameter it would be a better choice in my opinion. The drain pipe is going to heat soak in the sun where pvc would not. Think of it like a seat belt after its been in the sun. Cold air is performance air.

Sun? What's that?

It's already snowing here in the mountains.

And yeah.. I still have my stock pilot jet in. But I have a larger one I'm installing tonight, see if that works. Couple it with a valve adjustment and I should be driving a rocket. Took it for a good couple hours last night and it was really impressive.

Thanks guys.

Sun is something you might see once or twice a year up in the mountains. If on rare occasion you see it don't look directly at it.