Yamaha SR500 questions.

jasongroves, Dec 5, 3:11am
Afternoon all.
I am asking on behalf of a friend whom is a little stumped:)
The engine is fitted to another frame as a project (bopper).
#1 - Where abouts can he get a tool to remove the alternator/stator cover!
#2 - There are 3 white wires coming from the alternator and 3 white wires coming from the rectifier unit (aftermarket). How do you figure out which goes where, as the plugs are different and there are no identifying marks to help!
#3 - How to test CDI unit!

We have all the wiring diagrams, workshop manuals etc but they all just show 3 white to 3 white wires.
With everything wired up it instantly blows the fuse.
I know a little about electrics but nothing about bikes.so bear with me.lol.

crzyhrse, Dec 5, 4:16am
As soon as the ignition is switched on! Sounds like a simple short somewhere.

jsbike, Dec 6, 10:17pm
not electrical, but good sr500 info, and quite funny. http://www.youtube.com/watch!v=Ft1IkFZkJts

jasongroves, Dec 7, 3:41am
Thanks for the info:)
Am in the process of redoing the wiring, so should be able to eliminate shorts etc.
Will update when possible and hopefully have it running in the next week or so.

jasongroves, Dec 7, 3:46am
Seen it before, but still funny:)
Just sent a link to the owner.

richard198, Dec 7, 4:14am
I used to rewind stators and the first thing to do with your three wires from the alternator is make sure they are not grounding out.
If all three are still above then sweet!

jasongroves, Dec 7, 7:09am
Most of the info on the net just says try test CDI unit by replacing with a known working unit!

crzyhrse, Dec 7, 10:46am
So why are you wanting to test it!

You should start by checking the trigger.

jasongroves, Dec 7, 11:25am
Would just like to eliminate it as a possible problem.
Would explain a fair bit if the CDI was faulty and if its not, then we can start looking elsewhere for issues.
It was bought from out of town as a running project.as far as we can tell its never been running in its current state.
Sorry to sound dense, but what do you mean by 'checking the trigger'!
This is all a learning experience for me.I'm enjoying it though:)

richard198, Dec 7, 7:15pm
You are already planning to fail.
Why are you assuming it must be the CDI unit!
It may well be at fault, but you have to get it checked by the guys who specialise (Be wary of them, they have been known to tell your CDI is crook just to sell you another!)
Which fuse was blowing!
Does it short with CDI disconnected!

Edit:The trigger is the pulse coil situated near the rotor. (may be reason for no spark but unlikely to be your short)
Are your three alternator wires above ground!

trogedon, Dec 7, 7:58pm
I've got an SR500 (in bits, project). It's sad to see them end up as Bobbers or Flattrackers imho. Hope you get it sorted.

trogedon, Dec 7, 8:29pm
Great vid.

jasongroves, Dec 8, 1:02am
Its not my cup of tea either to be honest, but the owner likes it.
Pretty sure while drinking some fairly good quality whiskey.don't drink and TradeMe;)

jasongroves, Dec 8, 1:04am
Not assuming its the CDI but would like to be able to rule it out all the same.
It looks like its possibly been open before.
Will hopefully get around there today so have written myself some notes from this thread and will post back.

doug207, Dec 8, 1:17am
Test the resistance between any two of the three wires on the stator, should be more than 0.7ohm and no more than 1.2ohm or so.
You can test any two, but make sure you test all.
Test to see if it's grounding.
What colour are the wires on the reg/rec! And I'm assuming it's a 5 or 6 wire one!

The fuse blowing is your output wires on the reg/rec are wired up wrong.
If you get the stator cover off, check for signs of burned wires and burned epoxy (the crap that insulates the wire)
A stator is easy to re-wind yourself, have done it before.

jasongroves, Dec 8, 1:32am
Reg/rec is a 5 wire, 3 white, 1 red, 1 black.

crzyhrse, Dec 8, 2:44am
Red is positive to battery. I'm sure you can work out the rest.

richard198, Dec 8, 4:53am
I used to wind them for a living!
(OP, you'll be needing blow torch/oxy kit, special resin, fibreglass insulation tape and a friendly motor winding company that can spool of a few metres of freshly measured copper wire!) (And an oven.)

jasongroves, Dec 8, 7:03am
Thanks guys.
I will be around there tomorrow (with my many notes:) and will post back with results.