YFZ450 No spark??

[300EX_HMF]

i had put a new battery in my 450 because the other one had gone dead. so i put a new one in and now its not got any spark to the spark plug. so does any one know what i should check to solve this???

[hardkoratvmxr]

check all connections and grounds and you could have a bad solenoid

[300EX_HMF]

if the selonid is bad then wouldnt it not roll over? and i also had tryed jumping it from another atv when the battery was junk and i dunno if that might have fryed something or not?

[stc416rider]

Originally posted by hardkoratvmxr
check all connections and grounds and you could have a bad solenoid

did u do what he said

[300EX_HMF]

ya but how do i know if the selonoid is bad??

[ss440ex]

You did`nt happen to turn the idling up did you?
Turning it up can/will sometimes let the T.P.S. not send out spark once when shut off.
Hope that helped.

[300EX_HMF]

no i didnt mess with the idle

[bwamos]

Check kill switch

swap spark plug

get a multimeter and check if the coil is getting power on the 12 volt side.

If it is, then you have a bad spark plug, wire, or coil. If you don't work your way back.

[300EX_HMF]

ok i measured where the plug in goes into the spark plug cap and its reading 4.5v, but im trying to measure the ohm value of the coil which i think is part of the spark plug cap but i cant get a reading. i had put a new plug in it so i know the plug is good. so anything else im missing?? thanks!

[bwamos]

Originally posted by 300EX_HMF
ok i measured where the plug in goes into the spark plug cap and its reading 4.5v, but im trying to measure the ohm value of the coil which i think is part of the spark plug cap but i cant get a reading. i had put a new plug in it so i know the plug is good. so anything else im missing?? thanks!

The coil is the small cylindrical part mounted on the frame that the spark plug wire goes too. Spark plug wire comes out of the bottom, and should have wires coming out of the top. (about 3/4" dia x 1" long, not very big)

You will ahve to disconnect the wires coming out of the top of the coil to get a good ohm reading.. especially if something is grounding it out like the kill switch. As long as it's not an open circuit it "should" be ok.

#4 below is your coil.

[bwamos]

wiring harness.

#4 is the coil.

First though, check to make sure the power wire coming in isn't grounded. If it is it would indicate that the kill switch is most likely where your issue is.

[TRX520RIDER]

were your cables connect to your battery clean the off with a wire brush check your parking brake sometimes that screws up ur computer in the engine try putting on then slamming forward and yea check alll your connections hope i could help