Hey you guys going to be out at Danbury this weekend in the 50 degree temps?????

I could use a little schooling now that I finally got this YFZ broken in, a good 50 or so hours on it and fitted with some necessary equipment. When I rode with you guys before I had only 10 hours total ride time in my life on a 4 wheeler and this YFZ.

Don't forget the video camera either!

 

PUDLJUMPER: Hey, I have not tried going richer, the thing seems like it is too rich already. I would tell you the jetting that I am running, but dyno jet has their own funky number system (which is a long story in itself) and it wont make any sence to you, being that I should be running like a 165-170 keihin, and I am running a 138 dynojet. I guess their jets are not mukuni(spelling) or keihin, so the jets that they are telling me to use are 138 for 3000-6000ft, 134 for 6000 and above. I think it was like 142 for sealevel. I tried the 134, and the bike was way to lean. But I put the 138 back in and it was way to rich. I have messed with the needle. Its been on the 3rd 4th and 5th clip. Thus far it has run its best on the 4th, but still has that problem up top??
Messed up!! I am thinking about just going back to bigger keihin jets, and try to use my dynojet needle.

 

Hozed,,,

sorry about hyjacking your thread.. but

if Danbuy is too narrow.. could also meet up south of Eau Claire in Clark county.. trails are much wider there and those blind corners aren't as breath taking..

Hey I almost smacked a black bear up in Danbury last month ..right on the trail..


I'll have to give both locations a call and find out if they are closed or what///

 

Its not my thread you hyjacked, but thanks for caring! Actually, I think I may be the one to blame. It was someother fellows thread, and I started in on my own problems!

 

it was mine.. but my buddy called and he thinks he got it... ill find out tomorrow when we go riding i guess.. he doesnt know much bout quads tho.. that explains why he bought a yamaha..

 

well this is what I'm running on my YFZ..

full GYT-R exhaust system, dual stage GYTR filter with lid removed, 1000 feet

GYTR needle at 3 rd clip position from top
172 main
45 pilot
2 3/4 on the fuel mix screw



I was running
GYTR 4th clip
168 main
45 pilot
2 3/4 turns
and it was running rich in the mid range..


just changed to the 1st set up listed based on some recommendations of similar set up YFZs.

you need to know if he has the GYTR needle (yz bike needle) and lid off to match my suggestions.

 

Hozed should be glad that his Predator isn't in the same race class as my YFZ,(not that i'm good enough to take his *** yet ,but will throw one of his Bud's on my Machine and show him how it WILL chew him up and leave him choking on dust!) He'll be too far behind to choke on any exhaust though!Lmao
I think we've got it running to rich- but like Hozed said i haven't fooled around with many engines...it seems to run pretty good in low and mid-range, but on top end when you let off the gas it snaps and pops and backfires...makes me think its flooding itself(i could definitely be wrong) Right now we got a 48 pilot jet, 165 main jet, and we've got a gyt r needle in the fourth groove from the top.(it's what our Yamaha dealer said to do) and we got 4 turns out on the fuel mixture screw...(we're using a GYT R jet kit by the way!) We're going riding today so we'll really get a good chance to put it through some runs! Any input would be greatly appreciated! Gotta get ready to go tear up some turf!

2004 YFZ450- AC Racing front bumper, full GYT R Titanium exhaust system,
GYT R nerfs, GYT R air filter
(Gibson A-arms ,Axis shocks,and Lonestar axle coming in 2 days!)
(saving up for Burgard swing arms and thinking about putting on a kickstarter
and getting rid of 15 more lbs in weight)

 

YFZcrazy, I think your good on the pilot but I think your lean on the main. I'm going to try 48 pilot, 172 main, 5th clip position, 2 1/4 to 2 1/2 turns out. Every combination I have tried so far has the bike running lean so I'm going to keep going bigger until I get in the ball park and fine tune it from there.

 

Hey, It sounds more like your running too lean on top. Usually when your letting off the gas, and your having problems like backfiring, it means that its too lean. Have your tried a bigger main jet. More like a 170-172. I don't know a whole ton about jetting, but that is one thing that I have learned thus far. I would definitly try a bigger main jet.

 

crash929 kind a beat me to it!