No spark -- at a complete loss

[armourbl]

I have a 2008 CRF450R that won't start. I've owned the bike since new and it has never given me problems before. Somewhere around 80 hours total on the bike, only 8.3 hours on the new piston.

 

This morning, went out to ride and it wouldn't start. Figured out that there is no spark. Tested the coil, wire, and plug cap, as well as the leads to the stator. All are reading well within specs for ohm readings. Got a new plug, and still nothing. Also disconnected the kill switch, which also tested good on the multimeter.

 

Other troubleshooting performed includes: cleaned the carb and jets, checked the valves (all in spec), disconnected all wires behind the right radiator and connected them again.

 

Any ideas would greatly be appreciated.

 

ben

Edited December 31, 2016 by armourbl

[gotwings]

Switch out the cdi box if you can borrow one. If it's not that, then the pickup on the stator is suspect.

[armourbl]

One thing I should have mentioned is the last thing I did to the bike before I encountered the no start, no spark was changed the chain and sprockets. Has me wondering if maybe moving the wire for the stator out of the way for the front sprocket guard removal may be the cause.

 

ben

[Dirtclods]

may be the cause. Well?

[Eddie8v]

Is there a plug in the harness that comes out of the stator? Disconnect that and make sure all is clean and dry. I will assume you're holding the spark plug threaded body against a solid ground while kicking it when checking for spark, else you cannot complete the circuit.

[armourbl]

I ordered a new stator and will try it this weekend. Hoping that is the culprit.

 

ben

[Eddie8v]

I had a new one you could have borrowed, darn!

[armourbl]

Thanks Eddie. Given how far we live from each other, might have been more hassle than it was worth. I appreciate the offer though.

 

I used to have two 2008's at the same time, sure was wishing I still had the other for swapping parts.

 

ben

[armourbl]

Put a new stator in today and it still won't start. Very confusing. God this pisses me off.

Coil still showing good resistance numbers. Only things left are new coil and spark plug cap or a new CDI.

I'm so perplexed. Any ideas please?

Ben

[Eddie8v]

Put a new stator in today and it still won't start. Very confusing. God this pisses me off.

Coil still showing good resistance numbers. Only things left are new coil and spark plug cap or a new CDI.

I'm so perplexed. Any ideas please?

Ben

No spark with plug removed and resting against the frame? Must be some sort of electrical short or open circuit. Not sure if a bad CDI can cause a no-spark scenario.

[223hpyhooker]

Have you tried disconnecting the kill switch. Some times they ground out.

[armourbl]

I did try disconnecting the kill switch. But before I do any thing else or spend anymore money I'm going to give this another serious look.

 

ben

[armourbl]

So just tested the kill switch again. Disconnected no start. Tested resistance on wiresome from the switch and null, with button depressed got .04 reading. Tested continuity of the wires leading to the bike are they are good too.

Again the bike ran last time before I put it away. WTF.

Ben

[armourbl]

I pulled the CDI/ECU from the bike and cut back the cover on the wires the full length of the harness. No visible signs of damage to the wires and all checked fine for continuity with my multimeter.

 

One weird thing did happen when I connected it back to the bike after removing the wire cover. I got a vacuum like sound, very brief from the carb. Like some stored energy actuated the TPS on the carb or something. Probably nothing related to my issue, but thought I'd mention it.

 

ben

[armourbl]

I just ordered a used CDI off Ebay. Hopefully it is in good working condition as advertised. And even more so, hopefully it solves the issue with the bike. Now I just need to wait.

 

ben

[armourbl]

Received and installed the used CDI I got from Ebay tonight and the bike fired right up on the first kick like new. Looks like problem solved.

Thx for all of the help everyone.

Ben