summer time choke removal

[416racer]

I've done alot of looking on removing the choke and I still have a question. Do you need the bigger pilot even in the summer? Everything I've seen says for cold weather starting use a 42 pilot.
Thanks for any info.

Oh 1 more thing, do you think that removing the choke and grinding the header welds at the same time would be enough air flow difference to need the jetting changed?

[dalejiw25]

Choke removal isn't really something you want to put back together for winter time use. Your best bet would be to get another carb and strip the choke off of it strictly for summer riding or vica-versa.(be sure to cap the choke plate shaft opening after removal to prevent sucking air and dirt in) If you're gonna put it back together save everything as the butterflys are basically carb specific. At any rate you should be alright with the 42 pilot year round. As for your main jet, It will prolly need to go up 1 or 2 sizes.

[416racer]

ok thanks. Basiclly I wondered if the 42 pilot would work for year round.

[dalejiw25]

I've been runnin at least a 42 year round forever with no probs. I have an extra "winter" carb Just for ease. You can pick a used one up on e-bay usually for around $100. Or I can hook you up with one if needs be. Enjoy !!!!

[416racer]

Why have an extra carb? just for winter/summer jetting?

[CarGuy7a]

Originally posted by 416racer
Why have an extra carb? just for winter/summer jetting?

Because your jetting will vary depending on the temps and humidity.

In the summer months you'll generally have a leaner setup than you would in winter months.

Hot summer air is thin and less dense. Lighter air means the motor needs less fuel.

Cold winter air is heavier and more dense. Heavier air means more fuel is needed. This is why your quad will always run better in the winter months because it's pulling that dense "cold" air into the motor which in turn makes more hp.

Having 2 carbs can be a good way to do it. Set one up for no choke and summer jetting, and the other up for winter running with the choke still in it.

It's not completely necessary though if you leave the choke in like I do. I have my carb jetted just rich enough to run good in the summer, and is just right for the winter months.

Also for the 42 pilot jet. It may be too rich. At least for me it was. My 400 wouldn't even start with the 42 in it and the a/f screw at 1/2 turn.:eek2: I have to use a 40 pilot.

[TRXRacer1]

Originally posted by CarGuy7a
Because your jetting will vary depending on the temps and humidity.

In the summer months you'll generally have a leaner setup than you would in winter months.

Hot summer air is thin and less dense. Lighter air means the motor needs less fuel.

Cold winter air is heavier and more dense. Heavier air means more fuel is needed. This is why your quad will always run better in the winter months because it's pulling that dense "cold" air into the motor which in turn makes more hp.

Having 2 carbs can be a good way to do it. Set one up for no choke and summer jetting, and the other up for winter running with the choke still in it.

It's not completely necessary though if you leave the choke in like I do. I have my carb jetted just rich enough to run good in the summer, and is just right for the winter months.

Also for the 42 pilot jet. It may be too rich. At least for me it was. My 400 wouldn't even start with the 42 in it and the a/f screw at 1/2 turn.:eek2: I have to use a 40 pilot. Very well said! Every word.:chinese: