Another PWK28 jetting thread
- Thread starter Luni
- Start date
Blaner
Your Friendly South African Ambassador
http://www.blasterforum.com/engine-13/random-dying-out-41125/
this is what I did...
to line up with this
this is what I did...
to line up with this
I was able to get my holes to line up properly so I didnt have to worry about that. Well, Im going back out there to mess with it some more. Hopefully I can get it somewhat sorted.
Blaner
Your Friendly South African Ambassador
im going to order a kawasaki KX85 needle NAPF..hopefully that will help me!,,,stay in touch on here
I actually was wrong about my needle. It is an NAPF. So, you say thats the same as a JJH? Damn.
First thing I did today was clean out the carb again. As I thought, nothing came out, so that wasnt it. I also checked my float level, and for an eyeball job, I was spot on. 19mm pretty much dead on.
Ok, so I THINK I got it sorted. My final jetting numbers actually are leaner than Id think they should be, but it works. Im running a 35 pilot, air screw 1.5 out, slide adjustment set so it will die if airscrew is in all the way. 132 main (keep in mind guys, Im at 4500 feet, and I ride between 6000, and 10000 feet, so the 132 main might seem a little lean for me where Im at and it is, there was a TINY amount of detonation on it, it should be fine when I get up to altitude. However temp might ditcate I richen it up, so Im taking a 138 up with me.)
I did use my dial a jet, its set in the middle so no correction yet.
One thing Ive noticed. If you richen the main circuit up, your midrange gets a little better, but the top of the main circuit sucks, and its way too rich. I honestly think this little carb is just too small for my work on my engine, and I need something bigger. Im thinking it will rip a bit more with that 34pj once I get it on there.
But yeah, semi final numbers (I say that cause im going riding tomorrow on it and Ill post back after I have ridden it in real world terrain, not just in my neighborhood). 35 pilot, needle on the bottom clip (richened out for the mid), airscrew 1.5 out, 132 main.
Im thinking a 135 or that 138 main is the ticket. I know the 140 is too rich as it breaks up top, and the 132 doesnt. However I don thave a 135, and I dont wanna pull the 132 out as where Im riding will be about 2000 feet higher to start and end about 4000 feet higher than me, so Im leaving it lean to adjust for that altitude difference.
Oh, and another thing I learned today, at least on MY bike, with MY fuel, at MY location, plug chops are a total waste of time. You can get it either WAY too lean, and it will read, or WAY too rich, and it will read, but the good point it will just look clean like it was when I put it in. Ive done a bit of research on this, and our gashol fuel (10 percent ethanol) causes this. With the fuel we have (unless youre not running gashol), plug chops are worthless, they wont tell you anything. You jet the carb by feel and sound. You can hear when it is too rich, and you can feel when it breaks up. Likewise when youre too lean, its boggy, and and at WOT if your main circuit is too lean, you will hear detonation. Thats how I ended up jetting mine, cause my plug chops would only tell me I was too rich, but when Id back off, Id all of a sudden lose my color on the plug, and Id STILL be too rich.
Blaner, keep in touch with yours as well.
First thing I did today was clean out the carb again. As I thought, nothing came out, so that wasnt it. I also checked my float level, and for an eyeball job, I was spot on. 19mm pretty much dead on.
Ok, so I THINK I got it sorted. My final jetting numbers actually are leaner than Id think they should be, but it works. Im running a 35 pilot, air screw 1.5 out, slide adjustment set so it will die if airscrew is in all the way. 132 main (keep in mind guys, Im at 4500 feet, and I ride between 6000, and 10000 feet, so the 132 main might seem a little lean for me where Im at and it is, there was a TINY amount of detonation on it, it should be fine when I get up to altitude. However temp might ditcate I richen it up, so Im taking a 138 up with me.)
I did use my dial a jet, its set in the middle so no correction yet.
One thing Ive noticed. If you richen the main circuit up, your midrange gets a little better, but the top of the main circuit sucks, and its way too rich. I honestly think this little carb is just too small for my work on my engine, and I need something bigger. Im thinking it will rip a bit more with that 34pj once I get it on there.
But yeah, semi final numbers (I say that cause im going riding tomorrow on it and Ill post back after I have ridden it in real world terrain, not just in my neighborhood). 35 pilot, needle on the bottom clip (richened out for the mid), airscrew 1.5 out, 132 main.
Im thinking a 135 or that 138 main is the ticket. I know the 140 is too rich as it breaks up top, and the 132 doesnt. However I don thave a 135, and I dont wanna pull the 132 out as where Im riding will be about 2000 feet higher to start and end about 4000 feet higher than me, so Im leaving it lean to adjust for that altitude difference.
Oh, and another thing I learned today, at least on MY bike, with MY fuel, at MY location, plug chops are a total waste of time. You can get it either WAY too lean, and it will read, or WAY too rich, and it will read, but the good point it will just look clean like it was when I put it in. Ive done a bit of research on this, and our gashol fuel (10 percent ethanol) causes this. With the fuel we have (unless youre not running gashol), plug chops are worthless, they wont tell you anything. You jet the carb by feel and sound. You can hear when it is too rich, and you can feel when it breaks up. Likewise when youre too lean, its boggy, and and at WOT if your main circuit is too lean, you will hear detonation. Thats how I ended up jetting mine, cause my plug chops would only tell me I was too rich, but when Id back off, Id all of a sudden lose my color on the plug, and Id STILL be too rich.
Blaner, keep in touch with yours as well.
I have similar delema with the 28 mikuni I'm running. So far seems the best with needle i'm running now. Biggest issue I had was mikuni's needles change diameters with the same style needles, and needle taper heights. My issue was just off idle stumble with the needle I started with. Idle jet and main can be used to compensate jet needles. I have gone up and down mains with each needle I changed to what felt better at WOT,
I would recommand looking at taper height and needle diameters, But not remotely familar with keihin carbs. Other thing is if you got a needle that seems to have the right taper but is lean or rich you may wanna check your needle jet, the jet that is in between the needle and main. You'll have to pull it out the slide area of the carb.
I've been tempted to change mine to the size off the stock carb since mine is basicaly stock jug.
I would recommand looking at taper height and needle diameters, But not remotely familar with keihin carbs. Other thing is if you got a needle that seems to have the right taper but is lean or rich you may wanna check your needle jet, the jet that is in between the needle and main. You'll have to pull it out the slide area of the carb.
I've been tempted to change mine to the size off the stock carb since mine is basicaly stock jug.
Blaner
Your Friendly South African Ambassador
ok well im glad you coming right! 132 is very lean but then again you are very high (altitute wise! 
) im going to order a NAPF today and see what that does when i get it...
) im going to order a NAPF today and see what that does when i get it...
Today my ride started at 5800 feet, and ended at 9900 feet. So, thats a 4000 change. I was actually lean at 5800 feet, richened it up and it felt really good. By the time I was up to 9900 feet I was so rich I was fouling my plug unless I romped on it to clear it out every so often. I didnt foul the plug tho, it was definately rich.
The dial a jet I installed was pretty cool for this. I adjusted my airscrew to richen up the pilot a little, then I turned the dial a jet to one size richer and it immediately felt better. Once I got up to the higher elevation, I was able to back it off one turn on the dial a jet, and lean the airscrew out a little and it felt good again. Just doing the dial a jet helped the main circuit, but the airscrew gave me back my lowend transition onto the needle from the pilot.
So yeah, its jetted pretty decent. I think a different needle would help. Its odd. Currently Im running the NAPF on the bottom clip so its full rich. I think maybe I can get away with leaning the needle a clip, and going a size higher on the pilot, or just richening the airscrew a bit. I dont wanna go a size higher on the pilot if I can help it, cause most of the time Im riding at a higher elevation than I live, but I do all my work on it where I live.
Anyway. Pretty happy with it. Feels pretty good with the 132. But that 132 was being augmented by a dial a jet.
The dial a jet I installed was pretty cool for this. I adjusted my airscrew to richen up the pilot a little, then I turned the dial a jet to one size richer and it immediately felt better. Once I got up to the higher elevation, I was able to back it off one turn on the dial a jet, and lean the airscrew out a little and it felt good again. Just doing the dial a jet helped the main circuit, but the airscrew gave me back my lowend transition onto the needle from the pilot.
So yeah, its jetted pretty decent. I think a different needle would help. Its odd. Currently Im running the NAPF on the bottom clip so its full rich. I think maybe I can get away with leaning the needle a clip, and going a size higher on the pilot, or just richening the airscrew a bit. I dont wanna go a size higher on the pilot if I can help it, cause most of the time Im riding at a higher elevation than I live, but I do all my work on it where I live.
Anyway. Pretty happy with it. Feels pretty good with the 132. But that 132 was being augmented by a dial a jet.
Blaner
Your Friendly South African Ambassador
well thats good, ive ordered a JJH going to have to see how that works for me. how does the power feel??
Its felt pretty good actually. When I was jetting it in my neighborhood I was kinda like... Hmm. This doesnt feel much more than it was before I blew it up. But now that Ive ridden it on the trails, it fells pretty damn strong. I think I was pulling hills in 2nd gear yesterday where before Id have had to been in first.
My jetting isnt perfect either. Im pretty sure my pilot is too lean, and my needle is too rich. I have a slight bog to a rich area on throttle roll on. But Im actually thinking Im getting to the point where I can FEEL what circuit needs to be worked on and just address it.
I THINK Im getting good at this game
My jetting isnt perfect either. Im pretty sure my pilot is too lean, and my needle is too rich. I have a slight bog to a rich area on throttle roll on. But Im actually thinking Im getting to the point where I can FEEL what circuit needs to be worked on and just address it.
I THINK Im getting good at this game
Blaner
Your Friendly South African Ambassador
sounds champion. glad you getting the hang of it! i have an enduro tomorrow morning and just put the trusty ol' mikuni back. 30mm a problem for another day for now!
