KX Riders

Maintenance & Technical => KX450F / KX250F => Topic started by: fredunderwood on December 31, 2013, 08:23:10 AM

Title: Can't get it started
Post by: fredunderwood on December 31, 2013, 08:23:10 AM
Ok, I've got fuel, I've got spark, I've got air, I've got compression, but can't get my kx500 to start.....any ideas are appreciated.   This is a new assembly, so I haven't had it started before.
Title: Re: Can't get it started
Post by: Foxx4Beaver on December 31, 2013, 08:36:00 AM
what is your starting procedure?....this can make a difference.
Title: Re: Can't get it started
Post by: Foxx4Beaver on December 31, 2013, 08:41:42 AM
I don't mean to insult your intelligence, but I've seen even the most seasoned mechanics do it before by accident and pull their hair out for hours and even days...just to find out they forgot a paper towel/rag in the motor or exhaust, that was used to keep debris out during assembly.
Just another possibility.
Title: Re: Can't get it started
Post by: fredunderwood on December 31, 2013, 09:49:23 AM
Not at all insulted.   No rag
Title: Re: Can't get it started
Post by: Foxx4Beaver on December 31, 2013, 10:16:21 AM
you say you have fuel and spark...is the plug wet?
try disconnecting your kill switch.
Title: Re: Can't get it started
Post by: fredunderwood on December 31, 2013, 01:09:07 PM
Took the plug out, sparks, press kill button in and it doesn't.
Title: Re: Can't get it started
Post by: sandblaster on December 31, 2013, 01:46:57 PM
Assuming that your bike is mechanically sound and correctly jetted here is what I do.
Turn on the pet cock valve.
Lean the bike over until a little fuel drips out the over flow.
Straighten the bike up.
Turn on the choke.
Slowly rotate the engine until it is just past TDC.
Quickly jump up and kick a full swing on the kicker with all my weight.
Usually takes 2-3 tries before it will fire.
Anything less then my best effort kicking it over and it won't start.
Title: Re: Can't get it started
Post by: Foxx4Beaver on December 31, 2013, 11:10:37 PM
you had said in a previous thread right before X-mas that you had it running/idling, but as soon as you gave it throttle, it would die out, and then it would just kick back when you tried to start it again after that.

http://www.kxriders.com/forums/index.php/topic,12317.0.html

That "could" be a sheared flywheel key causing the kickbacks.

I just went through the same thing after installing a bigger brand new carb....I had to fatten up the pilot to get it to go above idle...once that was done it ran great, but fell flat on it's face in the upper revs....so I had to fatten up the main...now it has power all throughout....but, I still have a lot of fine tuning to do, and the weather is not ideal here for testing...15 degrees for high temps and we're expecting a ft of snow tomorrow and Friday, so I don't know when I'll get back to it.

I should also point out that mine was a COMPLETE rebuild....I'm actually embarrassed to say how much I spent this time.....and mine was a bitch to get started the 1st time, most likely from all the oil that was in the cylinder from assembly....it took 10-12 hard kicks.   
Title: Re: Can't get it started
Post by: fredunderwood on January 01, 2014, 09:55:59 AM
I'm gonna pull the flywheel today....but, I have read in a climber manual, if spark is "weak" versus a fat blue spark, that could be the problem....so subjectively, yes there is spark, but fat and blue???? Uh we'll?   I'm also going to check for connections versus the wiring diagram to see what I can find, but I have no answer to tell if my spark is weak versus fat????
Title: Re: Can't get it started
Post by: Foxx4Beaver on January 01, 2014, 10:01:31 AM
Take a browse through this thread when you get time....very helpful, useful info.
A lot of it you may already be aware of, but still good reading.

http://www.kxriders.com/forums/index.php/topic,10928.0.html

Keep us informed.
Title: Re: Can't get it started
Post by: motopunk on January 01, 2014, 06:47:29 PM
I'm gonna pull the flywheel today....but, I have read in a climber manual, if spark is "weak" versus a fat blue spark, that could be the problem....so subjectively, yes there is spark, but fat and blue???? Uh we'll?   I'm also going to check for connections versus the wiring diagram to see what I can find, but I have no answer to tell if my spark is weak versus fat????

if you retard the timing a little bit, the engine will start easier.. 
the spark must look strong ... it does not real matter if blue or white colored ...  i had the phenomenom that with one sparkplug blue spark and tryed another and made a white strong spark. performance on running mashine was no difference..  both plugs were brand new ngk br8 ecm 

what is your actual jetting?? that could also bring some light at this point.

another reason could be to much compression, that the engine dont start. which head-gasket is installed the 0,5mm or the 0,25mm that was optional available from kawasaki??  a second base gasket would also help...
Title: Re: Can't get it started
Post by: fredunderwood on January 02, 2014, 02:27:54 PM
Juuuuuuust a little update.    So, as I said earlier, I was going to pull the flywheel an test all connections.....right?   So I pull the stator cover.....can you guess whats coming?    The flywheel was spinning freely on the Crankshaft.......geeeze!   That's a problem, Right???????? :evil:
Title: Re: Can't get it started
Post by: Foxx4Beaver on January 02, 2014, 05:04:18 PM
haha.... that'd do it...I had a feeling that's what it was.
Title: Re: Can't get it started
Post by: motopunk on January 02, 2014, 09:09:29 PM
Juuuuuuust a little update.    So, as I said earlier, I was going to pull the flywheel an test all connections.....right?   So I pull the stator cover.....can you guess whats coming?    The flywheel was spinning freely on the Crankshaft.......geeeze!   That's a problem, Right???????? :evil:


fix it properly and give us some noise  :-D
Title: Re: Can't get it started
Post by: fredunderwood on January 03, 2014, 08:17:34 AM
What can I say......you guys totally Rock!!!!! 8-) And to think, I was just going to give up and take this to the shop and pay $400 to replace a $3.00 part!!!!!!!
Title: Re: Can't get it started
Post by: Foxx4Beaver on January 03, 2014, 08:31:03 AM
What can I say......you guys totally Rock!!!!! 8-) And to think, I was just going to give up and take this to the shop and pay $400 to replace a $3.00 part!!!!!!!

no problem...when you had said all it was doing was kicking back after it was running momentarily...that "normally" points to a sheared key.
don't ever be afraid to ask questions....there's a lot of smart guys here, and there's always someone on here that knows the answer.....the Hell with dealerships!! :-D
Title: Re: Can't get it started
Post by: motopunk on January 03, 2014, 07:25:29 PM
some times the smallest things make the biggest problems...  8-)   ...