Testing Stator

[mista_max]

Hi,

I'm troubleshooting a chargin issue . I don't get more than 12.6 V when I rev the engine. I checked the rectifire and it checked ok. That would leave the stator. The resistance check within spec. but have continutity between the leads and ground. Was wondering if that's normal. The procedure in the manual only checks for restitance between coils but no to ground. Is that normal. Is there another test I can run I was thinking of checking the Voltage between coils as the engine is running .

thanks

Max

 

[KJShover]

Do a search for the crimp fix or the hot starting problem, there are some nice write-ups on them.

Basically, its about revealing the crimp and getting some solder in the connection to improve its connection. Also like many, myself included, have bypassed the crimp by adding a more stout wires from the R/R's +/- directly to the battery's +/-. This, i'd say about 90% of the time got the charging back up to the 14v range. IF all else fails, there is always getting a newer style R/R off of eBay.

Here is a nice little write up on it.
http://vmaxforum.net/showthread.php?t=19108&highlight=Charging

.

 

[naughtyG]

Often I've seen the 3-way connector the stator wires go into disintegrate with age and heat, resulting in shorts that fry the stator. Check that connector and make sure it's good.

With the bike running, check the voltage between any two of the three stator wires, remembering it's AC current (not DC like the rest of the bike) and keeping your fingers off as it should rise to 50-60V AC as you rev up the motor.

But as KJ says, before all that do expose the main crimp connection under the seat and make sure it has been properly soldered. Also check all cable cores first in the crimp, as if they are corroded you may get shit continuity even after soldering. In this case it's best to cut out the corroded bits and soldering in new wires, making sure to use the right gauge of wire and some good quality heatshrink wrap to seal the connections.

 

[Bill Seward]

Newer style R/R is the way to go, as it has a specific ground wire, ready to hook up to the battery. Earlier units grounded through the footpeg mount, poor design at best, as any corrosion between the mount and frame lowered charge voltage and amps. Check output volts at the 3 white wires. Check across any two of them, in all combinations. If you have a significantly lower voltage reading between any two wires, stator is kaput. Carefully check the 3-wire connection from the stator.... Any problems here are gonna show up in charge voltage, too. These plugs are world-famous for corroding, and overheating because of increased resistance, even to the point of melting! (mine did!)...

If your stator checks out good, you might want to remove the plug altogether, and carefully solder these 3 connections. DONT cross them - keep insulated from each other and ground!!! Tape and heatshrink are the way to go here - and be sure the solder connections are done right. There is no order or specific way to wire these connections - any wire from stator can go to any wire to R/R. You're working with 3-phase AC here, and the bike doesn't care how you do it....

My stator lasted about 60,000 miles - the replacement is up to about 65,000 more. They seem reliable. Yamaha charges a fortune for a stator - there are plenty of aftermarket stators and R/R units available. I used a Rick's Motorsport Electrics stator in my Roadstar last fall, it seems fine, and puts out 20% more amps.

Good luck!

 

[Dr.n2o]

Also if u have continuity between any of the 3 wires from stator(not ground) then you have a short in the stator. They should read infinite

 

[Dr.n2o]

I bought one from this guy 3 years ago http://bit.ly/13e1BRW

 

[Fire-medic]

I am one of the "melted, crumbling stator plug club" members. It was brown and fell-apart in my fingers when I tried to release the connector. The 'solder/shrink-wrap insulator' idea is best.

And, as has been mentioned, if the regulator/rectifier goes-out, don't buy the OEM replacement, get the MOSFET upgrade for better performance from the component, and longer-life.

I think the Venture stator has a higher output, you could search for info on the amount, on here. Sorry, but I am too-lazy to do it.

Don't forget to secure your wires when you are done w/fresh tie-wraps.

 

[Rusty McNeil]

Also if u have continuity between any of the 3 wires from stator(not ground) then you have a short in the stator. They should read infinite

Wouldn't a short would read Zero ohms or close to it.
But isn't normal a few ohms, like 2,3 or so?

The three white wires are three points of either a Wye or Delta winding, they have to have continuity to make a circuit.

No continuity at all would be an open winding.

You are saying between any two of the three white wires right?

If you have any continuity from any white wire to ground then you have a grounded stator.

 

[Fire-medic]

Wouldn't a short would read Zero ohms or close to it.
But isn't normal a few ohms, like 2,3 or so?

The three white wires are three points of either a Wye or Delta winding, they have to have continuity to make a circuit.

No continuity at all would be an open winding.

You are saying between any two of the three white wires right?

If you have any continuity from any white wire to ground then you have a grounded stator.

Which is now junk. I agree w/Rusty.

 

[Dr.n2o]

You are correct Rusty....my screw up

 

[Luther 89 Max]

Hey all, so 89 vmax was testing at 12.2 sometimes 12.3 volts when I revved it up.. I tested the regulator rectifier and it was at 5:00 so which should be good. But now when doing in ohm test on the stator the three white wires I'm coming up with 35 between all three no matter what combination I run is that way out of whack or what's going on.. or does it mean that there's resistance there which it doesn't matter the value as long as there's resistance? Any info would help me greatly thanks in advance!!

 

[one2dmax]

Did you check all 12 tests on the regulator diode tree? It's almost always the reason these bikes don't charge. Also, when testing the stator are you using the AC output (not DC).