Jetting!!! Again and again and again!

[gowen]

Well, I've never been more happy with the 5hunny, she runs like a bat from hell and nothing is touching her. I'm using Spirits from BP (100octane), I also use C12 when available. Runs great! No surging or pinging (MUCH with 100 BP, none with C12).

Here is my complant, when trail riding and not running WFO all the time, it smokes like crazy! Usally 0-1/4 throttle , sometimes 1/4-1/2. Rarely wideopen. Can somebody post what has helped for them, as in, sea level running in 60-90 degree weather. It just feels mushy in the low-end, as in smokeing and just popping. I really wish I could just hire somebody to jet it correctly.

Aside from smoking, it runs great! Eats tires BAD, but runs great!

Thanks guys!

[kawdude]

I'm suffering from similar issues except mine is real clean on top.  I be watching this post intently.

[Paul]

Starting Point

You guys EVER gonna figure out the search function at the top of the forums?  

[kawdude]

Starting Point

You guys EVER gonna figure out the search function at the top of the forums?  

The search function is a wonderful tool and the jetting chart is great.  But neither have helped and I like to keep the experts on their toes.  

I have searched and found excellent information but not complete information just pieces here and there.  As far as the chart goes, it's only a starting point and I'm past that point but only because of the excellent information attained here.

[Paul]

Ok then, here goes...

If you're lean on top go to the next size main jet. I use a 178 @ ~ 2000' above sea level.

[gowen]

Starting Point

You guys EVER gonna figure out the search function at the top of the forums?  

Paul, I'm sorry if I keep posting the same ol' same ol'. The truth is, I do use the search button and I use it often. I understand the jetting chart and use it has a VERY useful reference. I have posted in the past that I had issues and I could have, I guess, just added to the previous post from eariler this year. But, since I'm having, supposely, new problems, I thought I'd make a new post. If it is a problem, please delete this post, I already tried to find a delete icon, didn't find it.

As far as what I found searching. I seem to have RICH jetting issues. But, I (for one), don't know how to test the crank pressure. I don't think it is leaking, as I am not losing oil. But, I'd hope not, if the magneto side is leaking it would be running extremely lean. So, if it was a crank leak, doubtful, it would be on the oil side. Which I am hoping is not an issue.

Just came back from riding this summer and noticed that the bike smokes alot after trail riding, runs great up high, but seems to have some blubber. Well, Here is what I have. I am running a 45 Pilot and a 160 main jet. I am in the middle with the niedle. I have a #7 slider which is showing no damage. Also am at a 2nd turn on the air screw.

I did notice some oil in the air box inside the filter, as it seems it may have too much air filter oil. But, this is pretty cosistant. I am curious why it feels sooo rich when I have the carb almost crazy lean. I have a 52 pilot, but I feel this could just make more smoke and spooge.

I have not cared about it until now, I feel it is being a power rob as it does not respond well and does NOT idle very well and smokes ALOT.

Thanks

EDIT:

Thinking about yesterday: I thought about how the bike rides, it is very "blubbery" in the low-end, bearly idles, and smokes alot when the gas is goosed. The mid-range is clean, no smoke and on through the top-end. Very strong pull, no noticeable pings (on race fuel). I'm guessing I am lean, as without it (race fuel 100bp or vp c12) it pings and surges.

Drawing a chart of what I have: What is stock: and what the jetting chart recommends:

Assuming: Sea Level and 79-100 degrees

|My Bike|Stock|Jetting Chart|

Main Jet: |160|168|165|
Slide Cutaway: |7|7|?| <-- assuming 7
Jet Needle: |N82M|N82M|?| <-- assuming stock (N82M)
Needle Position: |3|3|3|
Pilot Jet: |45|60|58|
Air Screw: |2.0|1.5|1.5|
Float Height: |Unknown|15-17mm|Unknown| <-- I need help in this area

From the looks I feel lean. I just bumped my Pilot from a 45 to 52, even though I feel rich down low, have yet to test. Will test when I can get out of work and the rain quits. I would like to also bump the main jet to a 165 and see how that works. The air screw does not help at all, I keep at 2.0. I would like to measure the float height. Is the stock numbers ok? I pulled them from my service manual. How can I test it? They are showing a special tool, is there another way? I am maybe thinking this is the problem   but don't quite know how yet.

Here is what I'm running, Boyesen Power reeds, FMF Desert pipe & silencer (powercore), egorr big bore with mid-top porting (520cc 2mm kit).

Sorry about the LOOOOOOOOOONG post, but I was told that I could be losing as much as 10-20hp potental power by having the jetting off.  

[Paul]

When was the last time the carb was torn completely apart and cleaned? I had an issue similar to this and found some Glamis residue in the tubes that the pilot and main jets thread into. If it's been awhile since the carb was cleaned then get some pipe cleaners and some carb cleaner and see what that does for you.

[gowen]

I got it apart now. I will give it a shot. Do you think by having a 45 Pilot that it was making it a PITA to start cold?  

[Paul]

Ummm, yeah.

I got it apart now. I will give it a shot. Do you think by having a 45 Pilot that it was making it a PITA to start cold?  

This is the big bore 520 correct? You maybe looking at a 180 - 182 @ sea level for a main jet.

[Sharc]

If you over-oiled your filter, it'll run rich with lean jets. And some filter oil may have found its way into your carb and gummed something up. Clean your carb out real good like Paul said, and put on a fresh lightly oiled filter just to get eliminate that as a possible cause...Paul's chart is darn close for jetting. 45 pilot is way too small. I'd guess the pilot circuit is clogged and it's sucking gas from somewhere else and loading-up your bottom end. And your reeds are ok, right...?

good luck.

Sharc

[gowen]

Ummm, yeah.

I got it apart now. I will give it a shot. Do you think by having a 45 Pilot that it was making it a PITA to start cold?  

This is the big bore 520 correct? You maybe looking at a 180 - 182 @ sea level for a main jet.

      My jetting is totally screwed up. I don't know how in hell it got so bad.

It seems powerful in the high-end. Do you think I should jump to a 180 from a 160? I was thinking like a 168. Just a thought.

Thanks

If you over-oiled your filter, it'll run rich with lean jets. And some filter oil may have found its way into your carb and gummed something up. Clean your carb out real good like Paul said, and put on a fresh lightly oiled filter just to get eliminate that as a possible cause...Paul's chart is darn close for jetting. 45 pilot is way too small. I'd guess the pilot circuit is clogged and it's sucking gas from somewhere else and loading-up your bottom end. And your reeds are ok, right...?

good luck.

Sharc

Thanks, I will take the air filter out tonight and give it a shot. I'm assuming that they (reeds) are good, I checked them a few months back and the looked good to me, not bent out or anything like that. One problem other than that I do have often is a nut viberating loseon the head often. It's like a center nut right in front f the spark plug and it spits water out. I'm just assuming this is ok, I just tighten it down. I think I will tear the KX down and inspect everything again this evening.

[kawdude]

This is great information!

Gowen,
Just for reference because this is your post, my bike is setup the same as yours with the exception of the pipe and my issues are with the mid range and topend.  As you know it's a 520 also.

It's currently jetted as...

168M
55P
2nd notch
#7 slide
wet air filter
1 1/4 turns out on the air.
14mm-16mm floats

Seems rich as heck.  First time I rode it after putting it back together ran great midway and up.  The next day lousy.  Could be that the bike was sucking oil from the filter and making it rich.  It could be that I'm really too lean now.

[gowen]

Kawdude, are you running at sea level? I'm going to buy a 168 main jet and have the dealership set the float height today. I'm going to try the main jet (168) and see how that effects the top-end. I have a feeling I'm lean but is running great, just one of those things I worry excessive about. I have a 52 pilot and am hoping it will help starting the bike. I hate to jump from a 160 to a 168 and screw the top-end up. But, I can always change back. I am going to clean the carb out and see how this hopefully works. I appreciate the input.

[kawdude]

I'm in Illinois.  So I'm guessing that I'm at 500-1000ft.  I'm going to drop the clip to the bottem and see what changes.  Becareful with the 52...letting off the gas on a hot piston with restricted amount of gas is a bad thing.  Someone made the comment that  52 may be too lean.  Let us know what happens.  I'm going to make my changes this weekend if the weathers ok and will do the same.

What's your plug look like?

I looked up my elevation...750ft.

Have you seen this link?
http://justkdx.dirtrider.net/carbtuning.html

[gowen]

Well, I just got back inside from the garage, and I did go ahead with a 170 Main Jet, also installed the 52 pilot. I have no other pilot jet, I will order a 55 tomarrow. As far as idling, it now does not idle anymore after changing the jets.

Ok, on to riding, I did manage to hit a few powerlines before the darkness took over. Here is what I came up with:

The top-end has improved alot! More hit and power. The mid range has felt like it weekened. The lower range feels not that great. I'd say bad. But, aside from that, once it is hot, it flies with WOT. But, hoping to fix the idling, I have the carb in cleaner. Hoping that it will fix any issues.