Suggested Extra carb jets to get?
Posted October 08, 2005 - 04:11 PM
My next step is to go the Yamaha dealer and get the other jets suggested in the guidelines (48 Pilot, 70 starter jet, #40 leak jet). As long as I am there, what are the other jet #s for the other jets that would be a good idea to pick up?
Posted October 08, 2005 - 04:32 PM
Posted October 08, 2005 - 05:16 PM
Main Jets - #160 thru #175
Pilot Jets - #42 - #50
Leak Jets - #0 - #60
Starter Jets - #65 - #72
Don't get them from your local dealer or you'll likely pay out the rectum. I'm a big fan of Zanotti's for the leak and starter jets as they're traditionally about half price, but you will pay for the shipping. Most independent shops will carry the pilots and mains for quite a bit cheaper as well. So there you have it...SC
Posted October 08, 2005 - 08:34 PM
Oh, the manual doesn't seem to show the standard leak jet and the Yamaha website doesn't show it in the parts section to get a part number. Anybody know what it is so I can look it up on Zanoti's?
And, there is no #72 or 75 starter jet on the Yamaha part website. Wazzup?
Posted October 09, 2005 - 05:41 AM
13 - Needle - 1/8 to 3/4 Throttle
19 - main jet - 3/4 to Full Throttle
20 - pilot jet (aka slow jet) - 0 to 1/4 Throttle
21 - starter jet (aka jet) - Choke Circuit
22 - Pilot Air Jet (aka jet) - Vacuum at Pilot Jet (small jet = high vacuum)
23 - Leak Jet (aka jet)- Accelerator Pump Circuit (smaller = more squirt)
Posted October 09, 2005 - 07:45 AM
you've got a 168 main. i run a 162 main at 600 ft above sea level with a Q2 exhaust and an opened up air box (indy mod). i ran a 155 when i was in colorado in august. put in a 40 leak jet and forget it. stock starter jet is a 65. change to a 72 when it gets to around 40 degrees or below. if you run too rich of a starter jet when it's warm and let the bike run with the choke on, you run the risk dumping too much gas into the bike. i learned this when my oil started to smell like gas!
dialing in the pilot jet can be complicated. there are almost too many options. not only is there a pilot jet, but there is also a pilot air jet. not to mention a pilot fuel screw. stock (45) is too lean and for some a 48 can be too rich. the fuel screw will help some with this. some of us went to a 100 pilot air jet ( YZ ), 70 is stock. there is supposed to be a ratio of between pilot jet size and pilot air jet size but i'm not sure where you can find that. when you go up on one, you need to go up on the other. i found that with a 48 pilot and a 100 pilot air, the idle would " hang " just a little. i tried to adjust it out with the fuel screw but i turned it out to the point i was afraid it might fall out. i went to a 85 pilot air jet and all is good. in colorado i went back to the stock 45/70 combo and the bike ran great.
i do run the jd needles. i change from red to blue when i change the starter jet (temps in the 40's). clip in the middle position. i only had to drop the needle (raise the clip) one position for colorado.
i know that was probably more info than you asked for but what i was trying to show was that you really don't need every jet made. a lot of work has been done by the '03 WR owners before you. some very good base line numbers are already there. i think this forum did a bunch of the work for jd. the original jd instructions had nothing about starter jets or leak jets.
Posted October 09, 2005 - 06:03 PM
You have the JD jetting kit, that comes with main jets. I would just get a
#48 and #50 pilot jets if you don't have them.
I wouldn't bother with any other jets, you can really muck things up. One thing to do for sure is keep track of the jets in your carb. Keep a note in the back of your manual so you will know what you have tried and what worked for different times of year.
Unless you have a dyno and a CO2 sniffer, you just have to go on feel.
You might feel the difference between 1 jet size, you may not.
Posted October 09, 2005 - 06:24 PM
Posted October 09, 2005 - 09:38 PM
Posted October 09, 2005 - 09:41 PM
Then, he gave me the pilot jet for free. Wow, what a turn around!
Posted October 10, 2005 - 03:12 PM
that's fine if you've got an '05 but '03's were way off. most of the stuff was figured out by '05. do the 40 leak jet also. '05 comes with a 50, '03 came with a 70. big difference when you snap the throttle.