any good recommendations for trail riding in 0-35 F temps?

I'd try 330 mains to start

No foam in the airbox and 300's were good for my 01 with stock pipes. That was the way it came from the dealer.

I have a 01 T-Cat and have been looking for the perfect settings too. So far I have removed the foam from everywhere inside the air box, but still have the foam at the air inlet by your feet. Look at where the air enters the top rear of the air box. You will see a vertical divider on each inlet. I cut this down to make the entry port larger and less restrictive. I will start this year with 310 mains and the needles dropped 0.030" with a shim kit.

Go slow a change one thing at a time.

BP

do the boysen reeds lean it out a little more than stock ones?

what is the shim kit you're talking about?

I had very good throtle response and nice plug color with 310 as cold as 0-F @1600 feet,I also found raising the needles one clip made the throtle response fat and the first year I had my 2000 Tcat it went tight in the middle hole at 1/4 throtle on the trail so I wouldn't be dropping the needles[hot spot at 1/4 throtle]

I cannot get the piston wash lean enough. The tops are almost all washed clean. This is when riding trails at less than 1/2 throttle. The gas mileage is not as good as it should be and I know the choke plungers are sealed. I have a return spring holding the lever down.

My motor has the upper case ported, exhaust ports widened, foam out of the air box with the inlet opened up. Horns and shelf still in. Stock pipes and muffler. Top end is very good, plugs run clean, never ever foul. Seems the midrange is fat. Stock pilots and starter jets. Air screws out 1 1/2 turns. Fuel screws out 1 turn. 320 mains and needle clip on center notch.

The shim kit is called 5-20 carb shim kit and is available from High Performance Engineering for $10. Three different thickness shim washers you put under the needle washer to adjust the height in 0.010" increments. Clip now raised 1 notch with 0.010" under the washer to shim it back up and 310 mains. This is what I will try now.

What is wrong?

BP

Big Pussy if you are that rich at part throtle I would drop your needles one clip.Since you engine is ported I'm sure the air flow at WOT is higher there for needs more fuel but the part throtle will have slower air volocity since it's ported and may need to be leaner at part throtle.If the 320 worked well at WOT last year I would start this year with the 320 and try dropping the needles???? The 310 may be lean for you as the temp drops

I think the stock slides are 3.0's. You could try 3.5's and of course they do not affect WOT jetting.


Auggie

i'm down to 300 mains. air/fuel screws turned out 1 1/2 and needles up one. still too rich down low. should be getting better fuel mileage. i went from under 5 MPG all stock up to 9 MPG right now. old 97 t-cat with the roundslides got 12 MPG plus. i usually only ride under 1/2 throttle. any sugestions?