No Spark

[necessity]

I've got a 2001 YFM350X that I cannot get to spark. On my last ride, it sputtered and died and then would not restart. Finally, after several minutes of wondering how long it would take my buddies to find me, it did restart just once- at least it got me back to camp= and I haven't been able to get a spark since. It still cranks strong.

I have a new battery, new starter coil, and new plug. I am getting 16,100 ohms from the positive lead on the starter coil to the spark plug electrode which I think is probably close enough to spec so that can all be eliminated as the problem.

Main switch tests fine. Cranks with kill switch on 'run' and does not crank with it on "stop" so I don't see how that could be the problem either.

I keep reading how rare it is for a CDI to fail- any other ideas????

 

[b_700x]

Sounds like a classic stator failure.

 

[1998yamahawarrior]

ohm the stator componets and compare them to specs in a repair manual, before condoning it as bad. also check your grounds for good connectivity and inspect wires for damage. check all conectors for corrosion

 

[necessity]

Except there is no stator in this model- totally electric strart

 

[necessity]

Since original post, I have also confirmed ground in to CDI is good. I have also disconnected, cleaned, and WD40'd the female side of all the pin connectors I can find. Still nada.

 

[fperri302]

There is def a stator thats what keeps your battery charged and also has two pickup coils for ignition system.....have a buddy pull you with a rope and dump the clutch with key on in about 2nd or 3rd gear ... if it starts good chance the one pick up went bad and you need new stator....

 

[1998yamahawarrior]

fperris right there is a stator is on the leftside of the motor where the wires come out of the engine

 

[necessity]

Yep got it now= 3 white wires would be the charging coil. Red/White matches my Clymer manual for the pickup coil. I'm getting 35 k-Ohms when the spec is 46-56 k-ohms. The other two wires that come out of the crank housing are red and green. My manual says the source coil wires should be red white/blue. But I don't see what else these other 2 wires could be and I'm getting only 4.5 m=ohms when the spec is 83 - 10 ohms ( a typo where the second spec is lower??? there are plenty of them in this manual- doesn't help) so I would be leaning towards source and/or pickup coil. Wish I understood what they even do? Does one of these tell the CDI the crank shaft position?

The manual wiring diagram calls all three of these together "CDI Magneto" Is that a Japanese translation for "alternator and pickup coil"?

 

[1998yamahawarrior]

ya the the source and pick-up coil both actually tell the cdi when to fire. one actually tells it to fire when starting and the other one when its running. If they are testing out of spec id say replace the stator. Get one thats either ricky stator or rm stator.

 

[bikewarrior350]

Your most likely looking at a wiring diagram for a different year. For some reason yamaha thought it would be funny to change wire colors from year to year and its the same problem ive had every time ive had to diagnose an electrical problem. Check out the free manual in the tutorials section. Theres wiring diagrams in the supplimentary sections at the beginning as well as in the electrical section.

Also if you are getting readings that are significantly lower (4.5 ohms for example) then one of the coils are bad.

Personnaly id recommend just replacing the whole stator assembly with pickup and source coils because sodering the wires are a pain in the ass since theres enamal coating on it but if your on a budget the individual peices can be replaced. Google RMstator they sell new units that arent as expensive as name brands but are still good quality. Ive bought 2 stators from them for both my bikes and they came with a full warrenty. Its a bit more expensive but i like the peice of mind that comes with the complete replacement part. You can order directly from there website but i found that there ebay listings tend to ship faster.

As to what a CDI does i can shed some light on that. The stator which is essentially an alternator is located behind the magnitized flywheel. As the flywheel spins it creates an electrical field which, for lack of a better term, the stator "obsorbs" which is the electricity that charges the battery. The CDI box has circutry that takes battery voltage and sends it to the source coil wich is attached to the stator inside the flywheel. As the flywheel turns a raised section on the outside comes close enough to the pickup coil so that electricity can jump from the source coil through the flyweel and to the pickup coil which tells the CDI to send voltage to the ignition coil to create a spark.

 

[necessity]

Very helpful info- thanks, all.

 

[tyler]

Could also be the trigger thats what it was on mine replaced it and she started right up!

 

[necessity]

Well, here's "the rest of the story" I couldn't get the pick up coil or the source coil to test correctly so i took it to a local Yamaha dealer who has a way to check all the stator components dynamically- he told me that when you test them statically, you don't always get the same result as when you put a load on them.

Guess what? His diagnosis- CDI unit. So, there must be a cheaper solution that the $500 retail Yamaha replacement part. I found one new made by Pro Com for $125. Any experience out there with this brand of CDI. Other ideas??? Thanks.

 

[tyler]

Check ebay and dont buy a used one and make sure its for your year warrior or the connections will not be the same.

 

[andryzzle]

Did you rule out that it wasn't for sure the stator? Mine was getting no spark either and when we went through the troubleshooting guide from the manual, the pickup coil was in line before the CDI box. I picked one up from RM stator, wired it up, and it didn't work. I flipped the wires per the instructions on the box, and sure enough, good to go... till it died 2 weeks later. Did you fix your issue?