Maintenance & Technical > KX500 Original

kx500 hard starting

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Br5hundo:
i got the tdc down, i had a cr500 when i was in my teens, its alittle more of a beast to kick when iam doing over 10 in a row,it only starts on choke, it idles fine when it runs, no bogg or anything, even my buds say its got to be jetting, iam trying to have it start within a few kicks hott/cold, i had to replace the kickboss already just trying to start it, it tends to only start from being primed from all the kicking,i did just email larry about the decompression valve thanks guys, dose the jetting seem right where i have it? and putting the new reeds and spacer would i need to change it?

Polar-Bus:

--- Quote from: Br5hundo on December 31, 2012, 11:00:45 AM ---hello everyone,
iam new to the forum and need some help with my 1989 kx500.iam having a hard time starting the beast. to help understand the issue il explain the bike. i bought it as a ice racer. it was lowered and had all the goodies. i converted it over the winter back to an mx racer. i was told i had to re jet the carb because it was jetted for winter not summer. i jetted to the fmf standards on the fmf website. it literally took me over 30 kicks to start it and about that everytime i start it now.it runs great but if i stall it or shut it off it dose the same when the engines hott. it often backfires while kicking it over every 6 kicks. ive brought it to a local shop where they checked electrical,timing and flywheel. a couple of my buds that are over 200lbs can start it within 10 kicks? the bike has fmf pipes, i think some engine work maybe a 540 kit? alot of money was put into this bike.trying to beable to ride the bike not look at it or almost pass out from kicking it.i no the tdc and been riding and racing mxbikes so its not a minor issue.
carb settings
1. main jet 175
2.pilot 62
3.3rd needle groove
4. 1.5 out air screw
5.0-1000ft elev.

iam putting on v force delta reeds and moose spacer this week.maybe i should be looking into a decompression valve or flywheel weight?
any info would help.

--- End quote ---

Do a compression test ? You have all the tell tale signs of a weak top end...

PS, your jetting looks too rich, especially the pilot , but don't take this comment as law, I generally don't like making jetting comments over the internet as there are so many jetting variables to deal with

Br5hundo:
with the jetting like i said thats what the fmf website said, it did have a 180 main and a 58 pilot from the winter jetting, to be honest i weigh 170 and can stand on the kick without it moving much so i dont think compression is an issue? thats why iam looking into the decompression valve cause after 6 kicks with this thing iam jumping off its a pain, i live in new hampshire and i ride in 200ft to 1000ft elevation so just trying to get a starting point with jetting since it wasnt stock when i got it, the main seems to be good, but pilot and needle position is what iam being told? when it dose start it idles, smokes alot at first then clears out, has great powerband, its only when its time to start it, i see other people almost give there kx500 half kicks out on the trails and starts right up?

serafin:
I would check your float height. Sounds like the float height is too low for the vacuum signal produced during start. 

S

81cr450:
1. main jet 168
2.pilot 58    if you have a 540 my expieirience is you need to go smaller even
3.3rd needle groove

 stock sea level I believe

Should be 2-3 kicks cold

Dont let me melt your motor though :-D
What do you weigh ? you might need to go on the all you can eat beer & doughnut diet

Your 58 pilot for winter jetting should go leaner with warmer air not richer, also you can stay rich on your main & clean it up after you deal with the starting problem. It'll save you getting to hot by dealing with one piece of the puzzle at a time

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