All 2st About the Mikuni/Keihin swap:

Give it a shot and see what you think. The reason I'm pushing bigger jets than these "Left" coast guys is that you are right at sea level, they are, for the most part, at 3000' +.

Also that you are a hard core racer and probable run the motor a little hotter than most.

Regardless, you are going to end up with the blue needle in #4 and a 45 or 48 pilot and a 175, 178 or 180 main jet.

Start with the 48 pilot at 2 turns open on the air screw. If you think the bottom is too sluggish then start opening the air screw 1/4 at a time until you are above 3.25 turns open.

If you don't think it's to rich then try closing it 1/4. if it gets harder to start, go back.

Start with the 178 main and see what you think. At wide open throttle it should run clean and strong.

I think the 178 is going to be your base main and the 175 will be more for 99+ degrees and low humidity. Very dry and very hot.

The 180 is going to be for < 45 degree, winter time and muddy.

Hi, here i am at see level and if i run my bike richer than a 42 pilot and my CEL needle more than clip 2-3, the bike will run with a lot of smoke and dont run crisp on idle/low rpm.
What oil ratio, brand of oil do you run ??? Maybe the smoke is related to my Mothul oil at 40/1 ??? I have had good luck with Mothul since i never blow an engine, but i have notice more smoke with this oil vs all other oil i have try.

I have my WR 300 jetted as follows: Sealevel and around 60-70F. For the woods i currently have JD red needle in 2nd slot from top, 40 pilot, airscrew 1,5 turns out and a 175 mainjet. On the street i use CEL needle in 1st slot from top because it´s leaner on very light throttle. It´s not the strongest position with the CEL needle, but for streetuse it´s the best i have. It gives me an almost totally clean run on constant throttle and no spooge. I have to lean my bike out for the woods too, because when i run the red needle in 3rd clip i foul my plug. I personally feel that there is no reason not to lean the bike from idle to light throttle. Why should it bludder on low revs and light throttle?

Johnny

It may be because you are on a 300. I haven't done "Hands on" jetting of a 300.

HUSKYNJ is on a 250. So, I feel pretty confident in what I'm suggesting.

I run KLOTZ Super Technaplate @ 50:1, which will actually make my air to fuel ratio slightly richer than yours.

The CEL has a straight diameter of 2.705.

The JD needles ( unless I have the wrong ones or my mic. is off ) have a 2.695 for the Blue, same as the "K" and 2.705 for the Red, same as your "L".

My Yamaha needle is a 2.695 for the "E" and 2.705 for the "F".

In the Honda needles a "69" is a "K" and a "70" is a "L".

I tend to ignore the "drool factor" because it's to riding style based and smoke can just be drool burning off, unless you ride looking backwards all the time or your buddies bitch about the smoke.

I am real excited about trying this new carb and will use the specs MOTORHEAD suggested for me. By the way, I run Klotz r-50 at 40:1 and only have an FMF pipe + FMF silence as far as engine 'mods" go.

My bike runs cleaner at low throttleopening with the CEL needle than with the JD red one. The CEL also has a longer straight section than the JD red one. JD red feels more like a "K" needle to me, on the 300 that is. The bike feels a little stronger in the middle with the JD red, and i guess it´s because it´s not a straight taper like the CEL. JD red is richer in the middle. It´s a more linear powercurve with the CEL. Bike idles perfectly with both needles at 60-70F with the 40 pilot and 1,5 turns out. I think i could even go for a "M" needle actually. EEM!

Johnny

Well Johnny, I'm not sure what to say about your stiuation. I've never been to Sweden and I haven't done hands on with the 300, let alone a Euro version.

Could it be your pipe has those big baffle plates inside of it ?

This is good. We are running pretty much the same set-up.

We should be able to get you dialed right in.

BTW- Thanks for the vote of confidence.

Hi Motorhead! The differences i talk about are very small when it comes to bludder for example. As i use my bike on the street too everything becomes very obvious as i use so small throttleopenings a lot of the time. For woods i don´t think i will go this lean, but my bike definetily runs very clean and don´t spooge. When i lay in 5th gear next to my friends KTM 300 2008 we are even on full throttle when i have 15/38 gearing and he has 15/40. That´s with the JD red needle in 1st slot. About the pipe: I don´t use the catalytic one. It´s the "full power" pipe.

Johnny

Yes, I can see how drool / smoke could be a problem riding around on the street like that.

I received my Motosportz Keihin Carb and JD jetting, but confused on what to do. I am trying to figure out the following that MOTORHEAD suggested for me:

JD blue #4 / 48 pilot / 180 main / 1-3/4 air screw.

Now I am looking at the little package that came with the package and it contains three items which are a needle with a red tip on the end, also what appears to be two mains that have 170 and then 180 written on them. How do I figure our the #4 setting and 48 pilot. I understand the 180 main and the 1-3/4 air screw part, but confused about the JD blue #4 / 48 pilot.. how do I identify these settings and what exactly needs to be done?

JD Blue #4 probably means to put the little clip on the blue JD needle in the 4th position. Look at the top of any needle and you'll see 5 or 6 grooves. Hopefully a clip came with your kit. That goes in to one of those grooves. The closer to the top of the needle, the leaner you're making it. The further down, the richer.

48 pilot means a 48 pilot jet. They're like twice the length of a main jet with a couple of little holes along the actual jet. A pilot jet mostly comes into effect at idle (with the throttle closed).

Thanks for the help. That helps to clarify things a bit. So when #4 would be 4 from the top or 4 from the bottom?

It'd be 4th from the top. You always count from the top.

I've only just learnt all these things myself this week, so don't take anything I say as 100% true :P

You're going to have to take the flaot bowl off and see what pilot and main jet are in the carb.

You want the 48 pilot and a 175 / 178 or 180 main jet in there.

Then you'll have to pull the slide out and remove the needle. It will take a 6mm nut driver or socket to remove the cable holder to get to the needle. You want the blue tip needle and the clip to be in the 4th slot from the top.

I just changed the needle / pilot and put the Keihin carb into the bike. For some reason, it is not starting now. Also, the throttle cable seems to be too long? It keeps coming out of the track on the throttle. Any ideas on that?

Take the straight tube out of the PWK top and replace it with the curved one from the TMX. Adjust the cable by the throttle, so slide fully closes.

Start cracking the throttle while you try to kick it over and you should fiind a place that it will start. Then you'll have to adjust the idle screw in until you get a good idle. After that it should start better.

That makes a lot sense and I will be trying those ideas out tomorrow morning. It was real strange because I was about to start up the bike up after installing everything and then noticed how loose the throttle was (tried giving it some throttle after it didn't light up after kicking it a bunch) and not tight like it should be.. and I quickly realized the cable was not staying on its guide up by the throttle on the bars. I will keep you guys posted and see if it works!

What jets do you have in it?