Author Topic: Jetting Guesses?  (Read 2460 times)

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Offline oic0

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Jetting Guesses?
« on: May 04, 2009, 08:36:37 AM »
Hate to ask this, but anyone got any guesses on what main jet I should start out with when jetting to avoid risk of piston melting when taking a plug reading? I cant find the old jetting matrix that I found links to while searching and the tuning list at the top of the page is a no go.

As far as I "know" the bike has:
a 1 over piston,
he said v-force reeds but the reed block I can see sandwiched doesn't look thick enough so maybe its replacement reeds on stock block
just ordered a pro circuit platinum 2 pipe to replace a heavily dented burly (pre lawsuit threat gnarly)
FMF powercore silencer

I am at 100-200ft above sea level in a very humid location with weather that ranges from close to zero in the winter to 100+ in the summer. Currently though it is in the 80s.

It might end up being ok where it is but I am not sure. It is a bit hard to start but I am not used to it and am kicking with tennis shoes. It falls flat on its face at high revs but the current pipe has two fairly deep crush spots on the head pipe so I don't want to rule that out. It was able to lug me around and idle and respond well to a WOT blip with some tire spin but it didn't seem to rev out very high. Again though, that is with the crushed gnarly type pipe. Won't things be a lot different with the pro circuit 2?

I don't want to blow a bunch of money buying every jet between 160 and 180 :( I do have some left over from my old RD350 build (twin PJ34s) but It only ran 165s.


« Last Edit: May 04, 2009, 09:17:39 AM by oic0 »
2000 KX500
1998 Warrior, with RD350 engine (Blown up)
1973 RD350 (In storage)

Offline Hillclimb#42

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Re: Jetting Guesses?
« Reply #1 on: May 04, 2009, 10:07:10 AM »
The jetting chart is a no go? Thats the best place to start. Thats what I did, from there it has only been needle adjustment or mixture screws. Richer than the chart is safer than going the other way, but it depends on alot. You and your questions will probably be moved to "Jetting again and again", its a good thread to go through.  Honestly it sounds like  you need to take it aprt anyway to see what you really have. V-force says so on the reed cage and most Kaws are a stock cylinder unless it sleeved. If the jetting chart isn't working, maybe you have something else to look for. You should post the year of your bike, exact problem that has. In the mean time, it'd be a good idea to get the carb apart cleaned, and check the float settings, overflows, jet sizes, clip position.
  Pro circuit has jetting recommendations to double check the chart. It will be close unless you are running a modified cylinder, or a worn one. Keep searching, you'd be surprised just how many problems guys have had with jetting which has resulted in lots of great info to find. Good luck.

Offline dsrtrider

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Re: Jetting Guesses?
« Reply #2 on: May 04, 2009, 01:28:38 PM »
here is procircuit jetting link

http://procircuit.com/jettingspecs.htm
current bike 2007 ktm 300 xc-w - keeping two strokes alive
1994 kx500 -sold-made me the man i am today

1990 kx500-sold
1982 kx250-sold
1979 rm125-sold
1978 kdx125 -sold
1977 xr75 - first bike

Offline oic0

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Re: Jetting Guesses?
« Reply #3 on: May 04, 2009, 02:43:41 PM »
not that the chart doesn't work, I couldnt find a working link lol. Not to say I didnt bumble past it, I can rarely even find my keys.
2000 KX500
1998 Warrior, with RD350 engine (Blown up)
1973 RD350 (In storage)

Offline dsrtrider

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Re: Jetting Guesses?
« Reply #4 on: May 05, 2009, 12:49:51 PM »
when you get to the site you click on year of bike then scroll down to your bike.  here is for a 1994 kx500

MODEL MAIN PILOT NEEDLE POS SCREW
KX500  168      60     N82M   3RD 1 1/2   

i have a pdf of tema green jetting specs i will attached as pdf i got from team green site       
current bike 2007 ktm 300 xc-w - keeping two strokes alive
1994 kx500 -sold-made me the man i am today

1990 kx500-sold
1982 kx250-sold
1979 rm125-sold
1978 kdx125 -sold
1977 xr75 - first bike

Offline Good

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Re: Jetting Guesses?
« Reply #5 on: May 06, 2009, 01:31:24 AM »
There is a working link in the Jetting again... thread but I'm not sure on what page.  I read that whole thread like 3 times!  I added the chart to my favorites on my computer :-D.

http://www.kxriders.com/forums/index.php?page=11

Offline oic0

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Re: Jetting Guesses?
« Reply #6 on: May 06, 2009, 01:41:30 AM »
Thank you both muchly! I'm going to go ahead and save the HTML files for all those pages. Just in case ;)
2000 KX500
1998 Warrior, with RD350 engine (Blown up)
1973 RD350 (In storage)