Choke- Does it richen @ high rpm's?

[TimG]

I've tried searching on this and found nothing. So I'm sorry for such a newbie-type question.

I'm taking my new (to me) sled on it's first trip. We unload at 2000 ft and ride to 7-8000. In the past I've jetted for up high and ridden w/ half choke up the trail, but I was on stockers and probably too rich anyways. This sled is a UBR 900 and I am more nervous. I want to jet so it's nice & crisp up high, but I sure as heck don't want to burn it down getting there.

So does the choke actually richen the a/f mixture at all throttle openings, or just at idle? I used to take for granted that it richened up everything, but then I read on mikuni's site that it only enrichens the small/no throttle openings. Is this a viable means for keeping an engine richer going up the trail? Anyone?

 

[BB454]

Choke

The choke circuit is seperate form the regular running circuit. It will continue to add fuel no matter what the RPM but due to the fact that it is controled by the vacume created by the motor, it will probably add less fuel when you pin the throttle. That's why they work better at idle, higher vacume there. For the purpose that you are talking about it will help. Also "blipping" the throttle will richen it up too. I have found that to be a better method once you get moving. Sometimes you can't get them to pull with the choke on. A combination of both methods should keep you safe.

 

[rmkboxer]

if you don't want to rejett fluctuate the throttle alot when down low don't hold it wide open and don't hold it in the midrange, but it will be richer with the choke on

 

[TimG]

Well, thanks. I guess I'll go for a ride and find out if it'll pull when choked, but all my other carbed sleds always did. I know mod guys will sometimes jet several times a day, and I'm not opposed to jetting up top if I have to, but the thought of jetting just before the ride down, when it's dark and I'm cold, wet, and tired, isn't very appealing.

 

[Mtn Escape]

Have you thought about trying an ATTAC?

 

[Kraven]

Holtzman ataac

Have you thought about trying an ATTAC?

x2, installed them on (5) sleds, 2 of which were mine POLARIS EDGE's, 600 & 800

AUTOMATICALLY ADJUSTS FOR TEMP & ALTITUDE

spot-on jetting, less than 1 hour to install

improved mileage and throttle response

approx $245.00

www.holtzmaneng.com

 

[TimG]

I thought about the attac, but after doing some reading, I found that it will lean the sled after it's been sitting for a few minutes with underhood heat. I'm scared of getting stuck, digging for a couple minutes, and then pinning the sled to get out, and having it go lean. I get stuck a lot.

 

[TimG]

Also: Does the ATTAC work well with nitrous?

 

[Mtn Escape]

I thought about the attac, but after doing some reading, I found that it will lean the sled after it's been sitting for a few minutes with underhood heat. I'm scared of getting stuck, digging for a couple minutes, and then pinning the sled to get out, and having it go lean. I get stuck a lot.

They say in the instruction to let it run for a few before pinning to allow cold air into the air box. About the NOS, don't know?

 

[slash]

I run mine with carb vents out of the air box at lower alts put them back in up top the vac in your air box will lean down your carbs about a jet size.

 

[Lake Cle Elum]

Do what you first talked about and just flip the choke lever up once in a while to cool the pistons. No need to leave it on...

 

[devilrmk]

powerjets is an option also, but the choke/throttle blip method works fine too.

 

[TimG]

I run mine with carb vents out of the air box at lower alts put them back in up top the vac in your air box will lean down your carbs about a jet size.

This sounds like a good idea. Anyone else do this?

 

[Taylzee]

I thought it was the tempaflow that had the issues with a semi warm motor. I thought the attac was safer.

 

[Mtn Escape]

I thought it was the tempaflow that had the issues with a semi warm motor. I thought the attac was safer.

Remember reading in the instructions during installation of mine to allow run for a bit to allow cool air into the air box before hammering on throttle.

 

[this1ultraflyz]

Get the ATTAC and don't look back. Works great.

 

[snowx22]

depends on the nitrous setup but I don't think the atacc or tempaflow with work with boondockers nitrous because they are going to work against each other with pressurizing the float bowls. boss or other similar should work.

Power jets work awesome for adding some fuel down low and are super easy to adjust at the end of the day. Check in to them if the choke/blirp method doesn't work

 

[sodfarmer]

This sounds like a good idea. Anyone else do this?

I run with my carb vents unhooked all the time around home and the beginning of the day up on the mountain. Plug them in when I can feel it running rich during the middle of the day. Makes a big difference in how the sled runs and very easy to do. Plus it's free.