84 replies to this topic

[fixitsan]

Following on from my charge problems, and seeking an alternative to the standard stator unit, I've fitted a BMW F650 stator (2000-onwards) today and it seems to be doing well. (£25 on ebay)

 

The dimensions of the standard stator are

OD - 115mm

ID - 54mm

h - 26.5mm

 

The F650 are..

OD - 115mm

ID - 54mm

h - 24mm

 

 

The pole coils of the F650 unit, on the left in the picture below, are not as long as the standard ones....but it is impossible to know the cross sectional area of the iron cores without dismantling them both. Based on the fact that the MY 2000 onwards F650 got fuel injection and needed an upgraded generator, and that the engine runs in the same sort of rev range most of the time as the TDM900, I reckoned it was worth a good bet.

 

 

 

Physically it's a drop in replacement for the standard unit except that the lead out wires leave the core in the opposite direction......this just needed the cable clamp to be unscrewed and a small hole on the other side of the core to be tapped and the wires could be brought out in the same direction. The 3 phase wires of the F650 which go to the harness plug are just an inch too short, or else this relocation of the clamp wouldn't be necessary.

 

 

 

Obviously the connecting wires need to be cut and soldered. I double layered heatshrink over the joints and wrapped each one in heatproof fibreglass insulation tape.

 

 

 

When first started up the bike was cold and on fast idle. Battery voltage was 14.45V....as the engine warmed and slowed the voltage stayed up at 14.45V

 

With high beam lights and brake light on the volts stayed over 14.4V.  Then the cooling fan kicked in and with high beam and brake light on the volts dipped to 13.7V but rose quickly back up after the fan had been on for a couple of seconds.

 

I guess it's working, but will it last ?   Unless it fails within a few months, I'll open it up to inspect it after a few months running, to check for signs of overheating.

 

If it does fail. I also have a Honda Firestorm stator on it's way to me ...cost £19 and is still fitted in the engine cover which i can probably sell for a tenner , wahay ! The Firestorm stator is 25mm high. VTR Firestorsm didn't come with FI as far as I'm aware, but it should be in the right ballpark in terms of output, perhaps wound to suit typically higher average RPM's ?

 

[fixitsan]

Here's the wires after soldering and taping , they tuck away nicely in a cover compartment

 

[fixitsan]

I've just found the following for the F650....

 

What is the Capacity of the Charging System

• F650 Classic: Has a 280 Watt, 20 amp charging system. Shank.
• F650GS/Dakar: Has a 400 Watt Charging System. Todd#389
• G650X: Reportedly a 280 Watt charging system. Winter #1935

 

Seems like the GS/Dakar is an upgrade for the F650, I would feel confident using that one forever in the TDM

Edited by fixitsan, 30 December 2015 - 04:10 pm.

[Studley Ramrod]

Well done !

[fixitsan]

I think another suitable candidate is the Aprilia 1000 stators.  They have a reputation for burning out the 500W stators and the 370W stator was fitted as an 'upgrade'. Anyhow i think the Electrix replacement might be a good contender, apparently Electrex parts are well made

 

http://www.electrexw...tml#aG815#aG815

 

 

But now the price is going over what a Robin Williams rewind costs.......

[JBX]

Nice job !

 

The 9er OEM stator outputs 440W - 14v / 31.5A @ 5000rpm.

[fixitsan]

Thanks I was struggling to find that info...

 

I might end up sending my original core off for rewinding !

 

I don't have any high draws, don't plan fitting heated grips, possibly some low power LED driving lamps.....it should hang together for me for at least as long as the battery stays good.

 

Strange that Aprilia reckoned that it's 500W stators were burning out so frequently because they output too much power. 35Amps is a lot for this gauge of wire, but the oil bath must help in some way. They retrofit 370W stators to any bike which has a record of burning stators up.

I'm only mentioning that because 440W isn't too far behind, and the TDM can burn them up easily, I've read even a rewound one burnt up (probably bad rewinding ?)

 

I have RAC breakdown and recovery, fingers crossed

[celticbiker]

Tbh I think it's down to oil flow.
I've had the original and two re winds burn out but marky mark had two oem stators burn out.
.

[fixitsan]

Interesting CB.
Mine burnt out at the two coils obscured by the lead out wires and connections. I suppose its possible to rotate the stator so that those poles sit in the lowest part of the cover and therefore make them more likely to get doused in oil

[fixitsan]

The Honda Firestorm (£19) stator arrived today, it looks like it has a bit more wire than the F650 but less than the started TDM, but physically it should be a perfect fit and the lead out wires are much longer than the F650 has.

[celticbiker]

Here's mine

[fixitsan]

.

Edited by fixitsan, 04 January 2016 - 02:41 pm.

[fixitsan]

A CBR500 stator is rated for 500W and oddly, the pickup coil also looks identical....in fact the grey plug looks identical to the TDM900..... 

 

The length of the pole coils is greater than the lower output stators I have for testing.....looks to be the same stator to me, but I haven't checked the dimensions......still costs more than a Robbie Williams rewind, but if someone happened to have one it would be worth a try

 

http://www.ebay.co.u...40AAOSwHnFVxHAn

[fixitsan]

Here's mine

 

 

 

 

 

 

 

 

 

What's the other side like ? Any sign of burning where the lead-out wires connect ?

[celticbiker]

No pictures but it was OK, I think on this stator assembly that the core was bad and chafed through the insulation shorting out the windings because mine always went to earth and it was always the same group of posts.
If I'd had a spare I would have stripped it and polished the posts then re wound it.

[fixitsan]

I'm thinking of rewinding my original....just a matter of finding the wire at the right price, copper prices are crazy !

[chrisr]

So is there a reason for this happening, a particular mileage or any warning, or is it just luck (or lack of it?) Is it worth having it rewound at a particular mileage just in case?

[muddy]

I was wondering if higher drain gadgets, such as heated grips, contribute to a quicker burnout?

[fixitsan]

A combination of higher mileage and higher drain, either/or, will probably do it.

 

From what I can gather the insulation to the core laminations is poor and the coils (possiblyy due to vibration)  eventually short to the core, or to one another.

 

There is a service advisory for Aprillia 1000cc models  (RSV, TUONO etc) to replace the 500W alternator with a 350W type, they seem to think that the higher power one is more capable of burning itself up due to the higher current it produces, that a minor intermittent short burns more rapidly.

 

Also if the bike hasn't been on a battery tender then after a startup the battery needs replenishing and the alternator works flat out, making over 30Amps. the wire diameter is the same as that used on 20Amp alternators and even they burn out, so 30Amps is a lot to ask, especially if it's sustained  

Worst case scenario = A low battery, just good enough to start the bike, on a cold day, takes a few goes to get it started, then all the lights come on and the rider maybe turns on heated grips ( a worse case scenario) is going to put the alternator to the test for a good few minutes until it can restore the charge lost by the battery during the start cranking. If it makes 30Amps it's going to get damned hot quickly. A lower power alternator, ironically, cannot get as hot in the first place.

[fixitsan]

Instead of rewinding periodically, it might be worth watching ebay (and other selling sites) for a late model CB500FA or CBR500 stator. They not only fit but they also seem to have the correct plug and ignition timing pickup. The only difference between one of those and a TDM900 seems to be a grommet on the outer case hole (The inner grommet is in the exact correct position too)....of course if you can't get a bargain one as backup then a £50 rewind is a great option.