#40 leak jet report on my 07

after reading many reccomendations about changing to a #40 leak jet on here i finally decided to try it...

my bike had been running poorly in the 0-1/8 throttle range before and i hoped this would fix it

all i can say is wow! :bonk: this really woke up my bottom end, i pulled a wheelie when the first time i twisted the throttle after installing this, i was so used to the sluggish bottom pull i was not ready at all for that front end lift :lol: and bark from my bike

i also tried to twist the throttle as fast as possible in neutral to see if it would stall like before and it wouldn't! :cheers: i tried with the clutch pulled in and the bike in gear, still no bog at all and instant response :thumbsup:

i now have my bike dialed pretty good(i think) for my elevation, here are my specs

bone stock engine

stock exhaust(dented like crazy)

50/50 mixture of 110 race fuel w/ lead and 93 pump gas

twin air airfilter

leak jet #40 (stock is 80)

42 pilot jet(stock)

180 jd jetting main jet(stock is 178)

jd jetting red needle in 4th position down

pro circuit fuel screw at 1 1/2-2 1/2 turns out

jd jetting thick o-ring around accelerator pump linkage

900-1400 ft elevation above sea level

80-95 degrees

little to very mild humidity

im very satisfied with my current settings,have no bog anywhere in the range, and this thing just rips from bottom to top

i tried testing it with the little o-ring, and without and developed a miss without one and a bog with the little one, it barks with the thicker o-ring though

im going to the track tommorrow and will give an update on how it performs there and ill do a race car style plug test to double check my main(WFO then kill it and roll) :thumbsup: hopefully i can help some people at a similar elevation to mine dial theirs in

HEY WOOPEE! MY 1000TH POST AND GOLD MEMBER STATUS! :busted:

Can't wait to here the results on the performance :thumbsup:

You have a yz rite, not a wr?

I wish that my #40 had that effect. I didn't notice any difference.

it performed well today at the track, it pulled from bottom to top just like when i first rode it after this mod

no bog whatsoever on the bottom and pulled clean every corner :thumbsup:

i would definately reccomend doing this if you haven't already

it was much crisper than before where it used to bog down some like a flat spot

yes, i have a yzf :thumbsup:

So did you have your jetting set up (almost) perfect before you did the leak jet change?

I would imagine that perfect jetting would further enhance the benefits gained by the leak jet change.

That is to say that you would get more gains from the LJ change than i would with stock jetting that may or may not be close to perfect for my area. (I wouldn't know if my jetting was right)

Does this make sense?

CrankR.

Hey Delta !! I have the ultimate leak jet solution for you. I got this little tip from a very good super moto racer and it absolutely cures your bog issues honest. Go out and buy any number size leak jet and soldier it shut completely, install and let her rip, don`t ask why, just try it. For a couple of bucks what do you have to loose ?

Hey Delta !! I have the ultimate leak jet solution for you. I got this little tip from a very good super moto racer and it absolutely cures your bog issues honest. Go out and buy any number size leak jet and soldier it shut completely, install and let her rip, don`t ask why, just try it. For a couple of bucks what do you have to loose ?

I have tried that too...the bike fell flat on it's face when I tried to ride it. I've tried the BK mod, O-ring mod, 100, 90 and 75 leak jets. I've timed my squirt to the 1/3-1/2 sec duration. The only thing that I haven't tried is the quickshot. At this point, I've all but surrendered to the bog.:thumbsup:

after reading many reccomendations about changing to a #40 leak jet on here i finally decided to try it...

my bike had been running poorly in the 0-1/8 throttle range before and i hoped this would fix it

i have the exact same problem with my WR, and i plan on putting in a #40 leak jet before my next ride.

ive never heard of the o-ring mod..what i is it?

Sounds great that you have a combination that is working good for you. For giggles, try to find a spot to do 3rd gear roll-ons. My bike seemed to get rich on the pump squirt and was real soggy on twisting the throttle with a 60 leak jet and the thick o-ring. Removing the o-ring made it way better and running the main jet down to 175 worked good with the stock needle. This also exposes some leanness in the pilot and I need to go up one to a 45 to smooth things out. I also didn't like to go to the JD needles as they are way richer than the stock one in the mid. Anyway, good job on the report and have fun. Oh, one more thing, does your bike get a little soggy when it gets heat soaked after a few laps? What air filter oil do you use?

Sounds great that you have a combination that is working good for you. For giggles, try to find a spot to do 3rd gear roll-ons. My bike seemed to get rich on the pump squirt and was real soggy on twisting the throttle with a 60 leak jet and the thick o-ring. Removing the o-ring made it way better and running the main jet down to 175 worked good with the stock needle. This also exposes some leanness in the pilot and I need to go up one to a 45 to smooth things out. I also didn't like to go to the JD needles as they are way richer than the stock one in the mid. Anyway, good job on the report and have fun. Oh, one more thing, does your bike get a little soggy when it gets heat soaked after a few laps? What air filter oil do you use?

Interesting Renrek. What's working well here in TX with 95deg, 70% humidity, 600' ASL is 175MJ, 3rd clip, 40PJ, 40LJ 1.75 out on FS with the oring mod on the accel pump. This not only works well on my bike, my buddy and local top tuner did this jetting on an 06 yzf with stock muffler and I rode it on the track yesterday and it ran almost as well as mine right up until it signed off way up in the rpms(pipe I'm guessing). I had a bog with the stock LJ and otherwise same jetting as stated if I hit the throttle hard in a 3rd gear corner. Before the next ride I changed the LJ and did the Oring mod and bog dissappeared.

Good question on the filter oil as that is a variable also. I use Belray Blue and squeeze the hell out of it and let it dry at least overnite before I ride.

Thats kool, when i put in my 40 leak jet i can't say i noticed much difference.

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