Jetting!!! Again and again and again!

[kawdude]

Mo better.  I haven't had a chance to continue my jetting quest.  Right now I'm at a 170 with the clip in the middle.  I moved it there from the secound clip and noticed a response difference.  Less snap.  Not a lot but it was different.  I will drop it back to a 165 and see what happens.

[mjscore]

My 94 came with  N82R as stock, is the N82M a leaner needle? According to the Kawaski web site it is not an option until later years. All I know is that no local Kawasaki dealer has one in stock so I will have to order it. Mine will only run with the clip in the first position and it surges on downhills. I have a 168 main with a 55 pilot and 2 turns out on the air screw.

[kawdude]

I think the R is richer.  The surges are coming from to much gas getting into the idle circuit.  Adjusting the pilot screw may help.  I don't know what you altitude is but dropping to a 52 pilot could remove the surges.  On my 94 I had to replace the slide and lean out the pilot.

[gowen]

Did replacing the slide help? I am thinking about that, just to see if it helps. I have a #6 slide, but the stock and what I have in it is a #7. But, no sign of being worn. Anyway, no reason just curious.

[kawdude]

My slide had a ding in one of the corners so it did make a difference.  Wasn't a perfect fix but lowering the pilot jet and fiddling with the air screw has helped bunches.

[kawdude]

My latest report...temp=75 @ 600ft.
Went down to 165 and it seemed to improve the topend.  So then I raised the clip to the 2nd notch and it seemed to help the mid top.  I will raise the clip to the top just to see what happens.  I also noticed that the old carb that I have has a #7 slide and I may play with that but as I stated above the slide is not in the best condition
 
The problem now is that the surges are back even though I leaned two of the circuits...weird!

I realize that neither circuit I adjusted deals with the idle but something is playing into the equation.  When the bike is surging I can change the number of surges by adjusting the air screw but it doesn't remove the surges.

Another thought...I did go to 40:1 and the surges seemed to get worse???  I don't understand this.

[gowen]

Kawdude, I went out riding the other day and I did not notice any surges. I've decided that I will keep moving down on the jetting until I find that I'm too lean, then will move back up a few. I did pull the plug again and find a clean tan plug. But, I've only had a few runs since the change in jetting.

Being that you had the porting job and big bore, I'd suggest trying race fuel. I hate to say it, but I had serious surging issues until I switched to the race fuel. Currently I'm running between VP U4 or C12 depending on which is in stock and I pay around $10/gal. If I can't get ahold of either I run to the local BP here and get the 100 octane Spirits fuel. Great stuff! 3.30 a gallon and not a single surge so far. It's worth a try. You can get the VP or usally any type of 100+ octane fuel from your local dealership or race track. Try calling or looking at some BP's for Spirits 100 octane.

Anyway, I plan on going out this Sunday and doing more testing with the jetting to see if I can find the perfect mixture in fuel/air and I'm still rich down low and I lost my 48 and 50 pilot. So, I need to reorder them. I'm hoping a 48 pilot will allow me to move the needle clip down one notch as I'm at the top. But, we will see!

Anyway, I enjoy playing with my jetting now that I have some guides to go by and have found a breakthough in the big K5. I started playing with the carbs on my other bikes and finding that quite a few are WAY to rich and the others are too lean, only found one to be on target and I always wondered why that bike never fouled plugs and was always crisp and scary.

It has been so busy here at work that I have not had time to touch my bike. Anyway, I have to overnight/saturday the pilots to get them before sundays testing. I'm starting to get so much power out of this bike I now am looking into dropping the gearing, as 5th gear 90mph wheelies are getting scary.

[gowen]

Well, I just got back from VA where I worked on my KX's jetting and did some testing. Well here goes:

Jetting: 162main, top clip needle, 52 main, 2 1/2 turns out on the air, #7 slide. I decided I'd get my cusin involved with me to tinker with the carb and see what we could come up with, well first, it was 80 degrees, 80% humidity, sunny, humit/hot as hell and ready to get this d**n thing streight. Well, I did ride it first before tinkering with it, running BP Spirits (100o leaded) mixed @ 32:1 using HPO, it ran great, alot of smoke and an idle! But, idle was weak, idle screw was all the way in. Running great! Twist and and shoot is the way the bike ran. Anyway, I started off by changing the pilot from a 52 to a 50 and moving the air screw back to 1.5 I fired the beast up (1st kick) and ripped the fields for about 30 minutes. Came back and it idled ok and a bit on the non-responsive side, even though it rips and does fine.  So, idling, I start moving the air screw out. Which helped a bit, but still too low but better than the 52. So, having moved out to 2.5 with better luck but not enough to satisfy myself, I installed a 48 pilot. Moved the air screw back to 1.5 and fired it up, idle!!!!! No, I mean REAL idle! Crisp responce. Very slight smoke and a ripping powerband, almost too much power down low! I'm not used to any power down low as it ran too rough. So, I decided to play with the air screw anyway, which I did, moving out to 2.5 helped a bit, making it smoother. I have a 45 pilot which I will not use as I'm VERY happy with the performance I have now. It ripped down low, pulling the wheel off the ground at a scary rate and if the throttle was moved to WFO it would rip/roar/slide and wheely all at once. Very nice. Anyway, I rode a tank and a half and it rocks! Rode until I hurt from holding on so tight. Vibes were not an issue, but I could bearly notice them, so thanks to mikesmith, I tried the expanding foam idea.. GONE! 125 vibes and jetting nearly perfect. What a wonderful day!

Anyway, I rode until about 6pm and decided to quit and load up, well I decided to do a slide around the field and noticed a bit of power loss in the half throttle section, so I'm assuming I need to raise the needle a notch. Aside from that, I could not be more happy with my K5 and the jetting. Retarding the timing as made the K5 run close to like a 125 type powerband, which is wonderful for me!

Anyway, my crisp responce is at:

162 Main
48 Pilot
1st notch (needle lowered max)
2.5 air screw
#7 slide
Ignition Timing Set at Right Mark (Retarted Mark)

Future Thoughts: (will post results as I do more testing this week)

45 Pilot (maybe get that Air Screw back to 1.5)
2nd Notch (lift needle a notch)

BTW, running BP 100 I have no surging or pinging what so ever.

It's wierd that the biggest performance improvement on the K5 is the jetting. Forget the pipes, big bores, turbos and what have you, having a perfect Air/Fuel mixture is the key.  

[mikesmith]

Glad you like the foam trick and you got your bike sortted out.Your right about the jetting,no mods worth the money if you dont have the 500 jetted right!

[Fookeneh]

It's wierd that the biggest performance improvement on the K5 is the jetting. Forget the pipes, big bores, turbos and what have you, having a perfect Air/Fuel mixture is the key.  


 
 exactly. this is why I would like to see a fuel injected 2 -stroke hit the market. perfect air fuel mixture, no matter  what elevation ,humidity, or temperature.

[kawdude]

Correct me if I'm wrong but doesn't the clip being set in the top notch signify that the pilot something??? Or is that the needle?

I got mine running OK.  Idles great and the top end is better but now the surges are terrible.  I may retard the timing slightly to see if that helps.

Anyway, my crisp responce is at:

162 Main
48 Pilot
1st notch (needle lowered max)
2.5 air screw
#7 slide
Ignition Timing Set at Right Mark (Retarted Mark)

[gowen]

Well, I decided to move to the 45 Pilot and that is it. Crisp Idle.. Anyway, just for thoughts, I broke my arm and hip yesterday in working on the jetting on the KX also got 1st degree burn on my right leg from the exhaust pipe. I guess that means I'm out of riding for a few months.

[mikesmith]

Ouch! Hope you get better soon,at least your bikes sorted out and ready for you!

[Rick]

Gowen, you broke your arm AND hip in one crash!!!  That must have been one big nasty get off...

During our recent recovery from broken bones, I was tempted to get on the bike early.  Glad I dind't, as I am now 100%.  However, it did take about 5 rides to get my head squared away.  I felt like every bump was going to cause a crash.

Heal Quick.

Rick

[gowen]

Thanks Guys, the hip fracture is minor, but enough to cause severe swelling. I shattered the bone right before the wrist, so that is the overall issue. Alot of burn treatment, casts, and I'm home.

As for the wreak, I was out on a developement highway not quite yet completed (still dirt), which I've done most of my carb testing here, well doing a 90-100mph 5th run, I at the last second noticed that they had added a few mountians of dirt  to the runway and trying to avoid them slid off the road hitting a large hole thrwing me and the bike down a 30ft hill. And besides a broken rear finder, gnarled sub frame, & a serious V shaped seat, It's fine. I had my buddy come and pick the bike up and he said it started first kick.

But anyway a cuncussion, fractured arm, hip and serious burns, I'm still alive! And my K5 is too, busted like me, but still running.