Jetting!!! Again and again and again!

[gowen]

Well, sorry it has been abit since the last update, I have been busy, got nailed by a ticket on the way back from VA and have had to entertain my cusin, which we did go riding yesterday. Well, I have not done much but the mods I listed above. But, here is a breif update: Clip (3rd), Main (170), Pilot (52), Needle (stock), Slide (#7), Air Screw (2 screws out), also cut the idle spring to about half to get it to idle. It has rained here alot and is humid as hell. But, I went out anyway, being it was still raining and it was breifly stoping.

It took FOREVER to warm the d**n thing up to where it would actually slide instead of sputter. Well, I don't know if it was humidity or what, but I had NO top-end power. It had a hell of a mid hit, but it would just fall flat on it's face in the top. So, I did decide to do some small drags (2 miles or so), it sputtered on the top real bad and took a while to get in the top and did not have any power when it would make it past. So, because I was not alone, I did not carry the lab tools (main jets ect.ect.), so I decided I may have screwed up the float height, so I took the carb apart at the truck and raised (leaned) the float height, then raised the clip one (2nd notch leaned), also screwed the idle screw out, so ito would not idle, and then rescrewed the pilot to 2nd turn. Did a few top-end runs, it ran like a dream! a huge hit in the top-end. Alot of mid and low, but serious top. Just like i like it. I then hit the trails again, being I had to be with my cusin, he fallowed me so d**n slowly that I was kinda bogging the bike around. Then when I hit the strip again, I had the SAME problem as before, all mid hit, no top-end and some bogging. Extremely rich feeling, and would not let it into the top. But, the power was hiting at the mid instead of the top.

Just a guess, but would this be the spark plug going bad? I have a BR8EIX and it has done great! I'm thinking a fouled plug.. I have been doing extremely stupid crazy stuff lately with the jetting and may have. I have had this plug in this bike for about 10 rides. Maybe needs changing it is seriously black.

Aside from that, then I did not think about the plug. So I removed the PV cover and fired it up and it seems to be working great! When you hit the mid rev, it openes half way, then a full throttle and it pulls all the way open. I'm assuming this is correct. I have the other carb in the carb cleaner to try it, maybe I have a screwed carb. I will first try the jets I just had and settings I had. Give it a shot then find out. Maybe it was the humidity. I can't come to richening it anymore, cause it feels like to is WAAY to rich. This is crazy and I know you guys are tired of hearing my moaning and groaning about it. I am too. I could get used to the power, but I am a sucker for topend hit and it is there, just with a d**n 160 main, 45 pilot and a (3rd needle position).

Can't test more tomarrow, I don't wanna test in the rain anyways and it is CONSTANT rain.. So, it should be clear by tomarrow evening, but will do more work Tuesday. If anybody has anymore input... PLEASE chip in. I will pick up a NEW plug tomarrow. If on Tuesday I get around to going riding and it does still hit at MID and not at the TOP. I will switch back to the origional jetting and just quit moaning and let you guys live a normal life.

But, any input is appreciated. I am willing to try just baout anything.

Thanks!!!

PS: One more thing to add:

The needle I have R1366N from Partsfish.com off the microfiche is 16009B
and the needle N82M from Buykawasaki.com is part # 16009B from the same fiche film. So, I'm assuming they are the same and diffrent manufactures? partsfish.com also recognizes the part # 16009G N82M, while Buykawasaki.com recognizes the part # 16009G for N89B from the same fiche film. Crazy and screwed up. I'm confused now. [/i]

[Twist-a-grip]

I don't want to be critical of your tuning but you seem to be trying to change too many things at once.  Be patient and tackle one circuit at a time. Your float level for example.  Any change here affects the jetting throughout the entire rev range of the engine.  If you drop your float level from the stock 16mm to say 18mm, you have just leaned out the entire fuel curve of the engine.  How?  Carburetors work on air pressure changes.  You have atmoshperic pressure on the fuel in the float bowl pushing the fuel up the main jet.  You have high velocity air movement over the top which creates a low pressure area above the needle jet/main jet.  This is what draws the fuel into the engine.  It takes either higher atmosperic pressure or an increase in the velocity of the air entering the carb to push/pull the fuel that extra 2mm.  Pretty difficult to control those.
  You are ready to jet if:
1.  Your float needle is not leaking
2.  Your float level is set to stock (constant)
3.  Air filter is clean and properly oiled
4.  No air leaks(crank seals,reed gaskets,base gasket, or engine side carb. boot)
  Start with the main jet.  This is 3/4 to full throttle only. Try the next step richer main jet.  If performance is the same or worse start leaning it out one step at a time until it just cleans up.  Stop.  You are done with the main.
  Next is the pilot/air screw.  Start with 1.5 turns out on the air screw ride the bike and take note of how it runs right off idle(throttle response).  Then turn the air screw out 1 full turn(2 1/2 total) and ride it again.  Did it get worse or better?  If worse go one step richer on your pilot jet.  If better go one step leaner on the pilot.  Use your air screw as a fine tuning device and a guide to determine what pilot jet you need.  Once you get this dialed in then your ready for the mid range (1/4-3/4 throttle)
  Start with the stock needle in the middle clip position and ride the bike.  Then move the clip down one notch (richer) ride it again taking note of the change in the 1/4-3/4 throttle performance.  Better or worse?  If better, continue to the next lower position until performance suffers then go back to the last "clean" position.  If worse move the clip up on the needle(leaner) until the bike runs clean.
  Sorry about the book here, but try it one circiut at a time.  This should get you very close.  There is always fine tuning with slide cutaways,different needles, and float levels if needed later for specific issues.
John

[mikesmith]

Thats good info from Twist a grip.I have to admit I got lost on most of your post,to many things going on at once.

[gowen]

Have a question, when idling, when I twist the throttle 1/8-1/4 should I get a clean rev through? In general I know this is the case, but I'm talking about the KX500, I've neverheard another one run. So, I'm having questions about how it SHOULD run. I'm having problems with it just chokeing and puffing down low. Riding or idling at 1/8-1/4 throttle opening. I feel that using a 170 on the main is pretty decent, no smoke, surges, or studdering (i don't think). But, I need to work on the 1/8-1/4. That is where I'm getting bad responce if any.
It just chugs and puffs. No throttle responce down low, from 1/2-3/4 it is good, and from 3/4-WOT it is powerful. Like Kawdude, I have no lowend responce. I get your suggestions, so, I'm assuming my issue is NOT jetting? As a 45 pilot does NOT idle and is not much better about responce as the 52 pilot.

[kawdude]

Mine does not chug at that throttle position.  I just did this so it's fresh in my mind...At idle and in neutral I snapped the throttle.  No hesitation what so ever very quick response.  Reminded me of a 250.  This response on mine is different since I rebuilt the bike.  Before it was sluggish.

Also, My problem seems to be 1/2 and above.  Could be lean, could be rich...hell i don't know.

[Twist-a-grip]

Try this:  Warm up the bike and hold the throttle to keep the RPM to where you think it should be idling.  Reach down and SLOWLY, gradually pull out the choke knob.  If the idle starts to go up you are lean on the pilot. If it starts to die out with only the slightest of movement you might be too rich.  Which reminds me of another possibility.  You might want to check the rubber seat surface of the choke assembly for damage as this would cause a slight rich condition.
John

[gowen]

Hi John, I just tried the choke deal (pulling the choke), but it just died. So, I just purchased a new choke, I will try that! Thanks.. I did go riding this evening before reading your post. It seems to ride fine until it is warmed up, then after it gets hot or I ride for about 10 minutes, the bike will not rev past the mid section, it can not achive the full throttle rev, no power up top, just mid power. I just checked the reeds again, look fine. Compression is fine. I will try the choke, I appreciate the input.

Ahh, I can't hold back, I'm headed out now to check the choke, I hope the neighbors don't mind a bit of noise at 11:30.    I am curious about this..

[gowen]

Well, here comes my resigination to this thread. I have tried everything everybody has suggested and nothing is working. Tested the stator,e ct.e ct. I seem to be out of ideas and so does everybody else. So, I will drop the KX at the shop tomarrow. Sorry guys, I am at my whitsend and have run out of ideas.

Thanks for the help guys!!!!!!! I appreciate it alot.

[kawdude]

If it does go to the shop let us know what they do.  I'm sorry the configurations haven't worked.

[gowen]

You can count on that Kawdude, I appreciate your input and help you have given me, maybe if I ever venture up your way, we can ride.

[kawdude]

It shouldn't be so d**n difficult.  Change this to get this effect, change that to get that effect.

Did you ever bounce the issue off Gore.  He should know since its his rebuild.

[gowen]

Yeah I know...  

[kawdude]

So is this where this ended?  Any further changes?

Well, sorry it has been abit since the last update, I have been busy, got nailed by a ticket on the way back from VA and have had to entertain my cusin, which we did go riding yesterday. Well, I have not done much but the mods I listed above. But, here is a breif update: Clip (3rd), Main (170), Pilot (52), Needle (stock), Slide (#7), Air Screw (2 screws out), also cut the idle spring to about half to get it to idle. It has rained here alot and is humid as hell. But, I went out anyway, being it was still raining and it was breifly stoping.

It took FOREVER to warm the d**n thing up to where it would actually slide instead of sputter. Well, I don't know if it was humidity or what, but I had NO top-end power. It had a hell of a mid hit, but it would just fall flat on it's face in the top. So, I did decide to do some small drags (2 miles or so), it sputtered on the top real bad and took a while to get in the top and did not have any power when it would make it past. So, because I was not alone, I did not carry the lab tools (main jets ect.ect.), so I decided I may have screwed up the float height, so I took the carb apart at the truck and raised (leaned) the float height, then raised the clip one (2nd notch leaned), also screwed the idle screw out, so ito would not idle, and then rescrewed the pilot to 2nd turn. Did a few top-end runs, it ran like a dream! a huge hit in the top-end. Alot of mid and low, but serious top. Just like i like it. I then hit the trails again, being I had to be with my cusin, he fallowed me so d**n slowly that I was kinda bogging the bike around. Then when I hit the strip again, I had the SAME problem as before, all mid hit, no top-end and some bogging. Extremely rich feeling, and would not let it into the top. But, the power was hiting at the mid instead of the top.

Just a guess, but would this be the spark plug going bad? I have a BR8EIX and it has done great! I'm thinking a fouled plug.. I have been doing extremely stupid crazy stuff lately with the jetting and may have. I have had this plug in this bike for about 10 rides. Maybe needs changing it is seriously black.

Aside from that, then I did not think about the plug. So I removed the PV cover and fired it up and it seems to be working great! When you hit the mid rev, it openes half way, then a full throttle and it pulls all the way open. I'm assuming this is correct. I have the other carb in the carb cleaner to try it, maybe I have a screwed carb. I will first try the jets I just had and settings I had. Give it a shot then find out. Maybe it was the humidity. I can't come to richening it anymore, cause it feels like to is WAAY to rich. This is crazy and I know you guys are tired of hearing my moaning and groaning about it. I am too. I could get used to the power, but I am a sucker for topend hit and it is there, just with a d**n 160 main, 45 pilot and a (3rd needle position).

Can't test more tomarrow, I don't wanna test in the rain anyways and it is CONSTANT rain.. So, it should be clear by tomarrow evening, but will do more work Tuesday. If anybody has anymore input... PLEASE chip in. I will pick up a NEW plug tomarrow. If on Tuesday I get around to going riding and it does still hit at MID and not at the TOP. I will switch back to the origional jetting and just quit moaning and let you guys live a normal life.

But, any input is appreciated. I am willing to try just baout anything.

Thanks!!!

PS: One more thing to add:

The needle I have R1366N from Partsfish.com off the microfiche is 16009B
and the needle N82M from Buykawasaki.com is part # 16009B from the same fiche film. So, I'm assuming they are the same and diffrent manufactures? partsfish.com also recognizes the part # 16009G N82M, while Buykawasaki.com recognizes the part # 16009G for N89B from the same fiche film. Crazy and screwed up. I'm confused now. [/i]

[kawdude]

Excellent Grammar!!!

So is this where this ended?  Any further changes?

[kawdude]

In reading through this I don't see that you ever did the plug chop test.  Did you do this?  According to above if the bike dies when you pull the choke you're too rich.  What happens with a jet one less than the 50?