KDXRIDER.NET

Well I've had this 98 KDX220 for a couple years now. When I first bought it it had no spark. Put a new stater in it from Ricks in Hamstead NH and the bike has run perfect ever since.

I have probably put a couple thousand miles on it easily. Bike always starts on third kick when cold with choke on and one kick when warm. Bike rips across the whole rpm range couldn't be happier with this bike.

Last Sunday it was running perfect as usual. After about 40 miles of perfection it just died on the trail. Like hitting the kill button.

I got it home. Checked for spark..... Has spark..... Cleaned the carb... Still no start. Checked compression and it's right at 120 psi as it's always been.... Put a new plug in it and drained all fuel out of carb and tank and replaced with 100 octain avavation fuel.... Still no start..... The only thing I noticed was that after a dozen kicks the plug is always dry like it's not getting gas..... Squirted starter fluid in plug hole.... Still nothing....local mechanic says could be crank seal...

Can the KDX go from running perfect one minute to nothing the next from losing a seal?

Would the bike still have good compression with a blown seal?

Do you all think this is the problem or have any other ideas? Thanks Mike

Remove the spark plug & make sure it's clean & sparking..

Next , while the plug is removed squirt some of your fuel mix down the plug hole , a couple of cap fulls should do the trick .
Kick the motor over very slowly a couple of times then re fit the spark plug...

Kick the motor over.... If the spark is good then the bike should fire up no problem...

If the motor dies after a few seconds then it sounds like a fuel blockage...check the float valve

Plug fouled? It's weird it would die like that. If it's got spark, fuel and air, it's got to fire. My 1st thought was it was the cdi but you've got spark so it's not that,
That's my biggest fear with these old bikes, it dies 50km from the truck.

The float bowl fills up with fuel as I can crack the drain bolt and fuel comes out. If there was dirt where fuel enters the carb wouldn't it overflow or not fill up at all? When I cleaned the carb I just cleaned the jets. I didn't remove the float pin or check the breather hoses.

jjavaman wrote:Plug fouled? It's weird it would die like that. If it's got spark, fuel and air, it's got to fire. My 1st thought was it was the cdi but you've got spark so it's not that,
That's my biggest fear with these old bikes, it dies 50km from the truck.

I'm always lucky when it comes to break downs. I was at a road crossing when it happened. And guy pulled over the minute he saw me getting off the bike and asked if I needed any help. Then drove me 8 miles up the road to my truck.

jjavaman wrote:Plug fouled? It's weird it would die like that. If it's got spark, fuel and air, it's got to fire. My 1st thought was it was the cdi but you've got spark so it's not that,
That's my biggest fear with these old bikes, it dies 50km from the truck.

As I stated I put a brand new plug in it.

KDXMainer wrote:Can the KDX go from running perfect one minute to nothing the next from losing a seal?

Not generally, usually it will start running lean eventually ending in a piston seizure. Never heard or a crank seal going and the bike just stops.

KDXMainer wrote:Would the bike still have good compression with a blown seal?

Yes it can. The only way to check the crank seals is a leak down test.

KDXMainer wrote:Do you all think this is the problem or have any other ideas? Thanks Mike

I don't think that's the problem if it was running fine and just died. I'd give all the wiring a good check, especially your grounds. Check the high tension lead, especially at the plug boot. You say you have spark, but is it a nice fat, blue one or a weak, yellowish one? It is possible that something in the CDI let go so that you get a spark, but not at the right time. Did you check your reeds as well when you saw that your plug appeared dry?

After reading everything you guys wrote my only stab in the dark suggestion would be to pull the flywheel and make sure the woodruff key didn't shear off. That could mess the timing up enough that it would have spark but not fire (I think). But the float bowl is full and the plug is dry.....weird. Maybe the pilot circuit is completely clogged. Have you tried to kick it over with the throttle wide open? I wish I had a better suggestion. Good luck and keep us posted when you figure it out.

John_S wrote:After reading everything you guys wrote my only stab in the dark suggestion would be to pull the flywheel and make sure the woodruff key didn't shear off. That could mess the timing up enough that it would have spark but not fire (I think). But the float bowl is full and the plug is dry.....weird. Maybe the pilot circuit is completely clogged. Have you tried to kick it over with the throttle wide open? I wish I had a better suggestion. Good luck and keep us posted when you figure it out.

Yes I tried opening the throttle...... Nothing. Have not checked reeds or pulled flywheel. I will try pouring some fuel down the plug hole next, then swapping the ignition coil from my 200. Also I have a brand new cdi unit sitting on my shelf. I'll post the conclusion to this when I figure it out.

Starter fluid instead of fuel.

I'm really sorry to hear about your troubles. My first thought was timing as well.

I still think you should try putting a few cap fulls of fuel mix down the plug hole....

If it fires for a few seconds then it's a possible fuel issue.... If it doesn't then it's more likely electrical , at least it narrows things down a little.

Starter

Fluid

ALMOST as explosive as Aqua-Net.

cornishwrecker220 wrote:I still think you should try putting a few cap fulls of fuel mix down the plug hole....

If it fires for a few seconds then it's a possible fuel issue.... If it doesn't then it's more likely electrical , at least it narrows things down a little.

That's next,

Jason wrote:Starter

Fluid

ALMOST as explosive as Aqua-Net.

Read my post. Already tried starter fluid.

Ah, sorry. My bad. I would say check electrical.

Jason wrote:Ah, sorry. My bad. I would say check electrical.

But in his first post, he says he has spark. Unless maybe you are meaning timing of the spark, or some other electrical issue?

fuel, air, spark

If he put enough starter fluid in it, it would light if it had spark and air. I doubt its an air problem.

Could it be something silly like a pinched wire somewhere? Maybe the kill switch is shorting out or something? Just spit balling here if everything else seems to be on the up and up.

Hey, KDXMainer, anything new to report?

A lot of us (well, me at least) are curious to know if you've found the cause of your problem, and what you did to solve it.