Jetting Questions


4 replies to this topic
  • mweitz

Posted October 06, 2010 - 05:46 PM

#1

Do you keep spare jets in your toolkit?

If so, how often do you need to use them.

Do you keep spares of what you have and some different sizes?

I pulled the carb on the WR tonight, I think I could rejet it in 30 or 40 minutes.

My bike currently has:

170 main
45 pilot

Leo Vince full titanium exhaust

03 YZ450 Cam

YZF450 Quad needle - set in 3rd position

Fuel screw 2 turns out

This is to run at sea level to 2K' or so.

(I bought the bike jetted like this)

If I went to 6K would I need to change the jetting and if so what is a good assortment to have on hand?

Thanks,

Mark

  • Flagstaff

Posted October 07, 2010 - 08:07 PM

#2

I don't know, I jetted based on recommedations posted here for 7000', ride 4000' to 10000' , am happy. Guess I'm not as sensative as some folks.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • William1

Posted October 07, 2010 - 10:35 PM

#3

I keep a full selection of needles, mains, pilots, leak jets and replacement parts.

Basic rule is if the elevation is more than 2,000', a rejet will make a noticable difference.

If you went to 6k, you would need to lean everything out. Probably at least a size on the pilot, main to 160, needle on the first clip at a minimum.

Fuel screw should be reset for temp/alt/air density change.

  • mweitz

Posted October 08, 2010 - 05:34 AM

#4

Thanks William.

I guess I'll just throw a jet in my regular orders here and there.

Mark

  • mweitz

Posted October 13, 2010 - 10:12 AM

#5

Hmmm, before we get too far, can I get some specifics.

This is how my bike is currently setup.

Year:2002
Model: 426
Cam Timing: 2003 YZ 450 CAM
Main jet:170
Pilot Jet:45
PAJ:STOCK
Leak Jet:STOCK
Starter Jet:STOCK
Fuel screw (turns out):2
Needle Model/Clip position:3 (Needle from YFZ 450 quad)
Grey Wire Mod (Y/N): Y
TPS Connected (Y/N): Y
Airbox Snorkel/Lid (on or off): OFF
AIS Removed (Y/N):N
Airfilter Brand:?
Exhaust Brand: Leo Vince full system
Average Altitude:Sealevel ( California)
Average Temperature: (60-90)
Average Humidity: 60-70
Degree of Satisfaction (0-10): 8
Additional Mods/Comments:

I would like to sometimes run a stock 01 YZ header and exhaust (I have a new one).

What would be a good place to start on jetting for that?

What would a good few main and pilot jets be to order to have on hand, say I want to order 4 or 5 of each to start with?

Thanks,

Mark




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.