cant get a 2010 ktm 50sx mini to start!

ok..this is what happened..just got the bike. kid took it out a couple times no problems..he ran out of gas one time, and like an ...... i drained mixed gas out of my bike not realizing its oil injection! so it starts revving higher and making less power so he stops riding....

drained gas..yatta yatta...but straight gas in it, go riding, no problems...he crashes and i cant get the bike started again.

cleaned carb, checked for spark, new plug..nothing....so i go ahead and check the reeds and put in a new piston. reeds are good...put it back together and nothing again....not even trying to start.

i even against my better judgement sprayed some starting fluid with no results...

i took the plug out again and kinda noticed the spark is white..i am seeing things and is this my problem-not have blue spark?

what else can i check...gotta get the kid riding!

What bike? You need spark at the right time, compression, and the right amount of gas.

Does it feel like it has good compression? Is the plug wet with gas?

Revving higher and making less power would suggest a lean condition - plugged jets or fuel filter, or air leak in the reed/carb boot or crank seal behind the flywheel and clutch. I have seen the seal behind the flywheel pop out on JR 50s.

The key in the flywheel can also shear off and alter the spark timing if the flywheel nut is not properly torqued. It is easy to check if you buy the puller tool for under $20.

Edited by gsa102

If you can see any spark at all it is probably good. The spark is very week until running. With the fuel turned on. Lift the back of the bike up until it is vertical. Drop the rear wheel, and try to start it after that. Hold the back up for 3-5 seconds.

I say never get a KTM get a Kawasaki and you will then have no trouble at all, but if you want to Keep the KTM first look for spark try the lifting it up and if that doesn't work then it's magnito ignition

Good Luck :)

flywheel is on the crank...i put a new piston in it thinking comp was the issue....are u guys serious about lifting the bike up? what does that do? it actually started yesterday....and now today nothing again...im going freaking crazy...i know how to work on bikes and this thing will not cooperate.

mag. tested good also.

Edited by 800screws

The ktm 50s are notorious for the stators (magneto coil) going bad and running poorly or intermittently. It may test ok, but still be bad with an intermittent fault.

If the flywheel key strips, it just turns out of time. It does not come off.

Edited by gsa102

The ktm 50s are notorious for the stators (magneto coil) going bad and running poorly or intermittently. It may test ok, but still be bad with an intermittent fault.

+1 also the wire runing from the stator to the coil has a little spade conection that I've seen become loose fitting casing the same issue's.

i drained mixed gas out of my bike not realizing its oil injection!

To be tottal honest.......I've seen tons of these bikes around and I've never heard of one having an oil injector on it......you did say a KTM 50sx?

The newest ones are oil injected, my buddy has a brand new leftover 2011 that is. And it only finshes races about 40% of the time, it overheats and has other issues.

I just fixed one with the exact same story, sometimes it would start and most times it would not. I have paid my dues as a mechanic for many years and this little pumpkin bike drove me crazy. I put a stator on it and it is good as new now.

After you kick it 4 thousand times trying to start it, is the plug wet? If so your problem is the spark. Just to double check the exhaust is not plugged up, remove it and try to start it.

i hear ya! i can rebuild a 2 stroke engine from the crank up...but this thing i cannot figure out! it might be for sale when i get it going....and then go yellow!

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