Sea Level to 5000' Jetting

[darth intel]

I have a 2003 Banshee with Toomey T6's, K&N airfilter, air box lid on, snorkel baffling removed. I'm planning a trip to St. Anthonys in Idaho and Little Sahara in Utah in July - and need some advice on Jetting.

The elevation at St Anthonys is ~ 4900' to 5400' , and Little Sahara is ~5100'.

 

My Banshee jetting is as follows:

Mains: 280

Pilots: 30 ( stock)

Needle ( stock position )

I've run it this way at Winchester Bay / Sand Lake (sea level) without any problems - runs great and has not fouled any plugs! According to the web link below, for a temp of 90F and altitude of 5500', the mains should be 2 sizes smaller, jet needle raised 1 clip position, and air screw out 1 turn.

http://204.71.0.3/motoprof/moto/mcycle/carb101/carb101.html

 

I've recently been told that 280 mains might be lean at sea level - and I plan on doing a plug chop in March to verify. I rarely run WOT - but have noticed that the quad doesn't accellerate like I would like at WOT. The front sprocket has also been reduced 1 tooth for "Duning".

 

I just pulled the plugs that have been used for 2 years - and link to pictures below.

http://community.webshots.com/album/207050119IVYybQ/1

 

Any advice would be appreciated - Thanks!

Edited January 16, 2005 by darth intel

[05bansh]

I'm not sure about the jetting for St. Anthony. But I ride little sahara here in utah almost every other week. As for your main thats pretty close to where you should be it sounds like. Maybe even a 270 since you are coming down in july and it will be warmer. I would even consider putting your clip on the needle to the 4th notch. On your pilots I beleive 25 are the stock size. Just make sure you bring extra jets and plugs with you and check your plugs. When in july are you coming to little sahara?

Edited January 16, 2005 by 05bansh

[darth intel]

I have a 36' Tahoe transport - so the plans are to stay in the Oasis camp ground JUly 5th - July 10th. I will buy main jet sizes 270, 260, 290, 300 and will do a plug check upon arrival. I want to remove the TORS system as well - need some instructions to do this.

 

 

I will also have check my 2 400EX's as well. The 400EX's are stock, but I'm going to add a Pro Circuit T4 slip on and a K&N filter before the trip.

[05bansh]

You should be good with those jets. That should give you a wide range of choices.

 

Do some searching to find info on the tors removal. I know there are a few companies who sell tors removal kits- toomey, and I think www.magicracing.com

 

Keep in touch between now and july with me and we will have to meet up and do some riding. I will most likely be down there 2 of the days you will be there.

 

Anybody else going to be there? We should all pick a day to meet up and have a bansheehq ride day

[Bansheerider29x]

One thing i know is 280 mains isnt lean at sea level. I run 270 mains and its perfect for me most of the time.

[darth intel]

Bansheerider29X,

From looking at my plugs from normal riding, they look a chocolate brown - thus I think the jetting is ok at sea level - but I'm going to check anyways with new plugs...will warm up the engine, change plugs, run WOT for 5-6 seconds then kill the engine and coast to a stop. Plugs will then be pulled and inspected - will also take pictures.

Thanks for the TORS information - I will check the Toomey web site for removal help.

 

It would be fun to meet up with the locals for a ride! I grew up in Murray and rode dirt bikes and 3 wheelers at Jerico for many years - the "pole" is a life saver!

[Banchetta]

Were these pics taken after a wot run in 6th gear??

[darth intel]

Those pictures were NOT taken after WOT in 6th gear! Those plugs have been in for 2 years - and the last 15 minutes riding was driving on the flats at mid trottle, followed by 1st gear idle through camp.

[Wallrat]

Man you need to change your plugs more often. Even with my bike jetted perfectly I change em out every few trips out to the dunes. Oh and put new ones in there. Cleaning them is a good quick fix to get back to camp but don't make a habit of it.

[Banchetta]

Run them at wot in 6th gear and take another pic....I change mine once a year. No need to change them if they aren't fouled. A perfectly jetted shee won't foul plugs.

[darth intel]

I will run them WOT in 6th gear and post pictures in March. I haven't changed the plugs since the bike has run good.

I'll be removing the TORS system this week and performing winter maint ( oil change, filter check, polish the rims and chrome.

Edited January 18, 2005 by darth intel

[darth intel]

I just purchased a Pro-circuit T4 slip on and K&N filter with outer wears for my son's 400EX.

 

From reading on the web concerning jetting - so far the conclusion would be to start with 155 main, 42 pilot, and needle clip on second position from the bottom, air screw out 3 turns. Dealer said to start 1 size larger on the main - 150. (Sea Level)

 

The 155 main sounds like a good starting point - what do others think?

[Banchetta]

From what I've experienced w/ my friends 400's, I'd go for the 155 main.

[darth intel]

Since I decided to run without the air box lid, I'm installing the 158 main, 42 pilot, and needle clip on the 2 slot from the needle end, air screw out 1/2 turn more than stock.

The plan is to start engine, let idle to warm up, adjust the air fuel mixture with the airscrew for best idle, set idle RPM with idle adjust, then ride and peroform a plug check.

 

I also purchased a rev box from White Bros.