I plan on doing the same with my new one. What year is yours? I still don't know what mods it has but it seems to go well in the trails. I don't have it's book yet so I'm not tearing in to it just yet just in case. I could adjust the the shock,but I know once I break out the tools I wont stop there. I would really like to find out what Revloc clutch it has in it and get some info on it. I know it is not evergoing to be my hoped up YZ, but would always like more out of it. Heck If I could get my lawn tractor to perform like my daughters TTR I would take that out on the trails.
Mine is a 2003 but I assume the jetting is the same with the main differences being how much you open up the airbox and how restrictive your exaust is. I cut the two upper openings out on the RH side of the airbox (left the lower part intact for some protection in water crossings), removed the backfire screen and replaced filter with Twin-Air that has the flame retardant treatment, and of course the snorklectomy. I'm eyeing some more spots to open up and trim also. I have the stock exuast but replaced the pea shooter with the GYTR one.
I did the full meal deal to my carb replacing all the orings, gaskets, jets, I put in the AP pump diaphram with the short pin available through Yamaha
so it gives a full squirt. I replaced the AP spring with the heavy KTM SXS one (only time in history KTM part was cheaper, 5.00 vs 15.00 for merge racing one). I also adjusted and tweaked the squirt till it was just missing the slide (I had to bend the arm that runs against the throttle cam on mine a few .001" but thats my usual luck..) If it dosen't have a adjustable air screw get a good one as I think its one of those things that we will jack with constantly..
There used to be a good thread on here about timing the squirt using a camera to record and measure length of the squirt but I don't see it anymore. I did a slighty hillbilly version and changed leak jets till the squirt was slightly shorter than a 1000 count, ie; slightly less than one second. I ended up with the 50 leak jet
to do this.
I studied a lot on here about jetting and chose to go with Krannie's? advice as it seems most people use the JD kit but I'm a firm believer in using OEM
needles instead of brass aftermarket ones and I was able to order everything from Yamaha
for much less than a JD kit. I can't attest to the needle and main jet yet (main jets in the east are mostly along for the ride anyway) but..165 Main
(seems a bit small, I'll do some corn field testing!)45 Pilot
(had a slight lean spot at 1/8 throttle and 3 turns on air screw, changed to 48 already, may need 45 in hot summer?)stock air jetstock power (starter) jet50 leakNCVS needle, 3rd clip
(I also got a NFLR needle to play with, would love to know what the secret Yamaha AIS kit needle is)
Oh and I fliped the air cut valve over to disable it (I hear they were invented by the devil himself).
Now I have to man up and actually ride this thing in the woods.. (I haven't ridden a bike that weighs more than 25 lbs in 12 years, I'm gonna die!)