Jetting questions, pingy etc

[JasonB]

Just got the motor running for the first time after the head leaking coolant issues. Runs great starts first kick choke up. Set air screw per standard; raise idle and back the air screw out to determine where the highest idle is and adjust pilot jet accordingly. I have a 48 pilot in my 39pwk and the highest idle was right around 1.5 turns out. I dropped the slide all the way down and it holds idle fine but dies occasionally; should I be adjusting my idle up a little to keep it ruining? Ran it three separate times through the day and it seemed like I had to play w the air screw and slide stop each time I ran it

I can touch the throttle and it winds out extremely fast! Very twitchy on the gas so I think I have the right sized pilot. It doesn't have a hanging idle but does seem to bounce a little when coming off throttle. Almost unnoticeable but it's there. Slide is dropped all the way and dgn needle is in the middle slot. Is the needle just lean or should I move it one notch?

[JasonB]

My only concern is that I have had to play w the air screw and adjus the slide stop a little each time to get the bike to run like I feel it should. The second and third time riding it the kept wanting to stall out really easy when engaging 1st gear and seemed to want ALOT of throttle to get out. The first time around the block the bike engaged 1st very willingly without the motor trying to stall. Just trying to learn this motor, it's my first 500

[freeride588]

People ask about jetting stuff all the time. The only answer I have heard that makes sense is all motors are different get a good baseline for you elavation type of riding etc etc and then start testing from there. Remember to have a fesh packed silencer as it will effect jetting.

[JasonB]

Ok I rode it more and after a good hard ride it will sit and ping/idle high like a big cam'd v8. Ping ping ping ping like it's not idling regularly. Is this bad reeds? I took the reed cage out and can see the slightest bit of light between the cage and petals. Will that cause irregular idle? Figured I would ask before I try a larger pilot, turns out I have a 45 in there and am considering a 48.

Bike is super responsive to even the touch of the throttle, I mean it zings up in neutral if I even look at the gas. Much more responsive than I thought this motor would be. when I let out the gas to take off in first the bike keeps trying to bog and it does take a second to get moving after the bike is rolling in gear; stab the throttle and it feels like it takes a second to clear out and get moving. Is this lean from the pilot or bad reeds or?

[freeride588]

Ok I rode it more and after a good hard ride it will sit and ping/idle high like a big cam'd v8. Ping ping ping ping like it's not idling regularly. Is this bad reeds? I took the reed cage out and can see the slightest bit of light between the cage and petals. Will that cause irregular idle? Figured I would ask before I try a larger pilot, turns out I have a 45 in there and am considering a 48.

Bike is super responsive to even the touch of the throttle, I mean it zings up in neutral if I even look at the gas. Much more responsive than I thought this motor would be. when I let out the gas to take off in first the bike keeps trying to bog and it does take a second to get moving after the bike is rolling in gear; stab the throttle and it feels like it takes a second to clear out and get moving. Is this lean from the pilot or bad reeds or?

The differnce between a 45 and a 48 pilot is nothing. Maybe try and read some of the many stickies on jetting and you are going to have to play with your settings. Unfortunately with jetting there is no 100 % right answer which seems to be what your looking for. Your descriptions of everything is very detailed but there are so many factors that are different that people cant just say use this pilot use this needle etc etc.

[JasonB]

i have been all over those jetting threads by roosty and alisobob. as far as I can tell I have the idle circuit dialed in well enough, i guess im just trying to determine what would make the bike idle like crap. I can get it to stay running but it sits there and idles a little too high for me. I am wondering if it could be the reeds that are a little worn out. anyways, I will keep searching around. I will be around a handfull of people later this week that have experience with 500's and should be able to help me determine why mine is acting up.


I just dont get why it bogs like it does when i let the clutch out, i mean it feels like it wants to die out. It feels like im taking off in 3rd when i engage the clutch into first from a dead stop; the bike shudders and feels like its going to stall out.

[Rhino89523]

You shouldn't see light through your reeds, if it takes a second to clear out and then goes that sounds more fat than lean. Bob is the man with the PWK's, I really don't know what you have going on but the bike shouldn't bog out in first....it should throw you on your back if you twist crazy in first.

[JasonB]

I just ordered a new set of Boyesens to replace these with. Of the three times I rode it yesterday the bike took off like it should have the first time I rode it, and then after playing with the air screw and slide stop the bike seemed to get pissed off at me and not want to take off from in 1st gear correctly.

[2strokeforever]

stall out really easy

not enough torque (regardless of RPMs) is a sign of pretty lean jetting
stalling too easy can be caused by lean jetting
also if it runs like a smaller cc bike that also can be a sign of lean jetting

start it from cold, turn the choke off after 5 seconds, let it idle 20 seconds, then turn it full throttle as fast as you can, if it goes booooowwwwwwwaaaa before catching or stalls out comletely then your too lean

your bike shouldnt surge at idle unless its just about to boil over 250f or higher coolant temps

ditch the using idle speed to set the airscrew buisness, its not gonna work at all.... go buy a zip ty airscrew, play with it and ride it, if you have the right pilot it wont take very long to figure out where and why it works best

I have a 48 pilot in my 39pwk and the highest idle was right around 1.5 turns out. I dropped the slide all the way down and it holds idle fine but dies occasionally

put your airscrew at 1/2 turn out and crank your idle up till it idles, use that as your starting point

if that dosent make it better you have an airleak

heres what you want it to sound like at low rpms
http://www.youtube.com/watch?v=5sBanbUraEQ

[AlisoBob]

if that dosent make it better you have an airleak

I guarantee it has a air leak.... EVERY 500 I have seen with a PWK needs the idle speed screw nearly all the way in. One bike needed a coil or two snipped from the spring to get the slide high enough to idle.

If the bike boggs like you say, that's another sign of being super lean.

Find your air leak....

[JasonB]

checked this morning before work, the idle screw is all the way in. interesting. I will get some video up this evening of it idling to see if anyone has any input. I did hit it with some starter fluid when it was running sunday and the idle didnt fluctuate at all

[AlisoBob]

I dropped the slide all the way down and it holds idle fine but dies occasionally..

What does this mean then?

[Kuma]

checked this morning before work, the idle screw is all the way in. interesting. I will get some video up this evening of it idling to see if anyone has any input. I did hit it with some starter fluid when it was running sunday and the idle didnt fluctuate at all

Air leaks can happen in many places on a 2 stroke, crank shaft seals are one place that comes to mind.

[JasonB]

I dropped the slide all the way down and it holds idle fine but dies occasionally..

What does this mean then?

when i was messing with it sunday, i backed the screw out all the way to let the slide sit at its lowest point. It would idle but die frequently, i kept messing with the air screw and the slide stop to get the bike to idle when it sounded like it was happy. I just need more time with this motor.


Im going to look at crank seals next if I cant get this figured out. I may just be paranoid and not jetting correctly here either, I have no freaking idea what im doing and just going off what I have read in the primers on here from Alisobob and Roostius. I will be around some people that know these bike on thursday and should be able to get some actual feed back, this shit is hard to convey online lol

[AlisoBob]

I would raise the needle before taking it out again.

[JasonB]

I don't know what changed but the bike runs mint. Slide stop all the way in and air screw out 1 turn bike is ride- able and wants to go. And it idles. Thanks for the help guys, don't mean to throw some stupid ass questions out here but my main concern is making her happy, I will shoot video for people to give opinions on, can't wait to lug this fat whore around