KX500 Wont Start!!!!

[don46]

Depending on how bad, the reeds could be the culprit or maybe even a blown crank seal. as all have said, spark (at the right time, compression and fuel and it should start.

[DoldGuy]

and Air 

[cass]

HI GUYS CHECKED REEDS TODAY THERE OK ! REPLACED NGK CAP , CLEANED FLY WHEEL AND THE PICK UP`S ON STATOR PLATE! STILL WONT START! WOULD IT DRAW AIR FROM POWER VALVE SEAL WERE THE ROD COMES OUT OF THE SIDE OF CYLINDER AS IT WAS A BIT OILY WHEN I TOOK THE COVER OFF? GOING TO BUY MORE PLUGS MABEE I GOT TWO DUDS FROM MX SHOP!   I`LL KEEP YOU POSTED CHEERS

[Friar-Tuck]

 Cass, this is really a buggar...
I'm tempted to send you my flywheel and pick-up to try..
  If the plugs don't do it send me a P.M. and if you'll pay to ship them back to me I'll take them off and pay to ship to you.
  Tuck\o/

[cbxracer30]

Is there any chance you somehow got water down in the motor [preasure washed it,left it out in rain] ? I had an older rm250 one time, the powervalve breather came off and water got down in the motor. I had to pull motor, pull the top end and wash the bottomend out with fresh fuel before putting it back together and it fired first kick.

[cass]

cheers for the offer friar tuck ! but i have to decline your offer as i stay in the uk , and it would be crazy to send it over to me . the guy`s on this site are so genuine and helpfull .  i tried starting it today just wetting the plug all the time, took mag and stator plate off again now theres a small amount of black oily fuel on the crank seal i take it is blown ? i just replaced them when i did the rebuild. including crank case bearings ! bike has only been ran it 1-2 hours puttering around so what caused them to blow? still waiting to get new plugs! tied my jetski plugs in it and still nothing?

[tharden]

Know this is getting interesting.  This is what I think has happened.  You replaced everything in the engine, but you may have a blockage in your pipe.  You are getting too much back pressure on the engine and developing too much crank case pressure causing the seals to blow out.  try starting the bike without the muffler or pipe and see what happens.

[KXcam22]

cbxRACER,
  Thats a new one for me but a great idea.  I know a bike with a soaking wet air filter won't start with all the water vapour drawn in. A puddle in the bottom of the crank case would do much the same. I'll add that one to the memory bank.  A plugged exhasut pipe will definitely prevent it from starting but I can't say that I have ever encountered that except when I am an idiot and leave my butt plug thingy in my silencer.  Cam.

[GDubb]

butt plug thingy

... that's funny.


-G

[kwakman]

cass,
       sounds like you may have a cdi problem to me, you seemed to have checked everythin else, so as i noticed u said ur in uk, try westcountry windings for a replacement. when mine died corby kwak wanted over 200 quid, but westcountry do one for about 115 all in.hth. you can get em on 01279 731172.

[cass]

hi guys got new plugs spark today!. spark is  still prety s**t!  if i earth plug to the pipe, coil and plug spark and it jumps to pipe ok . but if you try and use one of the head bolts  the spark is s**t! it still wont start! just took clutch case off.  power valve was not engaging into mech so would that stop it from starting? ie; valve ports not moving . im due to torch this f**ker because it should be running ! ive had this baby from 1991/ it`s a 89 uk model so me and this bike has a lot of history . ive just restored it back to new and its doing this to me! should have left it the way it was an old dog that still went! i will post pictures of  before and after only when its running the way it used to  !

[cbxracer30]

cass,
      when you say you just restored your bike , did you paint the frame ? If you did , you may not have a good ground at the coil. If you did paint it ,the best thing to do is grind the paint off the frame where the coil mounts for a good ground.  Also are you sure you have good compression and motor also spin freely with the plug out ? A bad crank bearing will seem like compression. Just some thoughts hope you get it figured out RonM.

[cass]

cheers for  the advice, have already buffed paint of at coil , also every bearing and seal changed on engine! now fuel is leaking from crank into mag ?. does this mean seal is f**ked because  it wont spark right. Ie flooding it self > what causes crank seals to fail when there brand new?

[Hillclimb#42]

 A little weeping is no big deal. Also, the spark doesn't look bright like a car or truch, IMO. I had a hard time seeing mine also, until I checked in the dark. More often then not, it has spark or no spark. Its not too often that its a weak spark, unless its a deal like that on a loose or bad ground. I'd say you are chasing a cylinder issue or carb problem. If the crank seal was bad, it would still run. I know this is basic, but does fuel poor freely from petcock? How bout when tipped over, does it come out of overflows? Exhaust is definately clear? U tried different throttle positions? Hows the kicker working? I have to get it just right on the sweet spot on top, so I get 2 cycles or it won't start. Especially right after the rings set-in and compression was the highest.
Air leaks or blown gaskets, will usually make it rev high.

[Jopiz]

Offtopic:

What does a good spark look like? Is blue and fat good and white is bad?

-J