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Stator Time

10K views 76 replies 13 participants last post by  oshoshan 
#1 ·
Hi everyone,

Some stator questions:

I read a lot that the stators of the Turbos keep failing.

Is there a way to prevent the stator from going bad?
Are the expensive ones (Ricks Motorsport for example) are more lasting than the cheap eBay ones?
Does a MOSFET R/R resolves the issue (or have any impact of the life span of the stator)?

Thanks!
 
#44 ·
The 847 looks much bigger (not stock footprint) and my assumption is that it also outputs way more current which we may not need?
 
#47 ·
Yes, it is physically larger and rated for higher current (I.e. it can produce more current should the stator provided higher currents and the motorcycle electric system demanded more current). However, for a given stator and load, the 847 will produce the same, potentially at better efficiency (take less from the stator in order to produce the same to the load).
The main draw back of the 775 compared to the 847 is that it is not performing as well at high rpm. True, our bikes don’t run at 10k+ rpm. However, efficiency is not a step function- it’s gradual. Thus, I assume that the 847 would be more efficient at reasonable rpms as well, 7k, 8k and all the way up to the redline. If I’m going to switch to a new ragulator I’d want to switch to the best available... even if it is better only by 5% and only at very high rpm.
 
#48 ·
So which one ?? The SH775 35 amps or the SH847 50 amps ??

Well lets look at the reported problems : Triump Speed Triple at 9000 RPM
Lets look at it's charging system : Triump Speed Triple 34 Amps at 5000 RPM
I don't think it is wise to run a regulator which is barely capable enough to run at 5000 rpm and run it at 9000 rpm !
RPM or switching times are here not a problem : 9000 rpm / 60 x 6 (stator pole groups ) = 0.0009 Mhz
Problems for switching semiconductors are a limited voltage span in which they will work correctly.
So I believe the high voltage at 9000 rpm plus the ?? 50 Amps output is way to much for the SH775

So fine if you use the SH847 but I personally think that the SH775 will do just fine
 
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#49 ·
Every time I see this thread I wonder if there is room on a Turbo for something along the lines of the "poorboy" conversion for 4 cylinder GoldWings. On the 'Wings it involves adding a V belt pulley in front of the pulley on the crankshaft that drives the cam belts (& a hole in the belt covers for it to pass through) to drive a 1 wire car alternator mounted on a bracket attached to the bike's frame, all of which can be done with the engine in the frame
 
#50 ·
Not sure where you'd put the takeoff on a CX engine.
 
#51 ·
Someone was talking about trying it on a a normally aspirated CX/GL500 a few years ago. IIRC, the plan was to mount an electric fan in front of the rad so they could mount a pulley in place of the mechanical fan.
I don't know how that would translate to a Turbo, though...
 
#52 ·
I don't know how that would translate to a Turbo, though...
Maybe we can run a bicycle alternator directly from the Turbo , surely 80.000 RPM plus should be enough ......
 
#59 ·
The problem with that is that I seldom have a passenger...
But I do currently have a 500 engine (normally aspirated) in a bike that has an electric fan and the rad isn't in front of the engine so if I get bored I might consider thinking about running a car alternator from the front of the camshaft......

BTW: How does the MOSFET reg/rec that Muttay sells compare to the Shindengen ones?
 
#60 ·
I've got a FH020AA saved in my eBay watchlist. Not sure where that came from.
How do we determine which Shindengen model is correct for our CX/GL?

Thanks,

Randall
 
#61 ·
Lot's off SH775s on eBay from this seller:

Randall
 
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#62 ·
The Compu Fire 55402 is another series RR to consider, 40 amp rating I believe. Smaller footprint than the SH847. Have one installed on my 1000 V-Strom, works well - replaced a Rick's Motorsport Hotshot RR.
 
#66 ·
Engine back on the bike, new Ricks-Motorsports Stator is in, plus SH775AA RR.
Hopefully this is the last stator replacement ever.. :)
 
#67 ·
SH775 update:
I carefully monitored the Voltage provided by the SH775 in the last months:

As long as I keep the RPM below 7K, I get 13.5-14.0 volts on the SH775 outputs (connected directly to the battery). I get at least 13.0 at idle.

At 7K-7.5K the SH775 misbehaves: the voltage leaps to 15V for a few seconds every minute or so. This behavior becomes worse as the RPM goes higher and the weather gets hotter.

At 8K and above, the SH775 doesn't keep up and the voltage across the battery exceeds 15 (definitely over charging the battery and may cause lethal damage to the electrical components).
 
#69 ·
Pim, I believe you did some testing with the alternator set up in a lathe. Did you find anything similar? Does Oshoshan maybe have a bad unit?
 
#72 ·
R&R update:

I've had the SH775 for 2 years now, and about 10K miles. It worked as it did new - basically perfect all the way up to 7500 rpm. At 7500 and above, it would occasionally stop regulating and over-charge up to 15.5 volts. I obviously never stayed at that RPM for more than a second.

A couple of weeks ago I replaced the SH775 with SH847. Lo and behold, it provides a steady 14.1V from idle to 8000 rpm. It has the same connectors, so now electrical modifications were needed. It is physically larger, which meant that I have to remove the bracket that holds the various connectors. Yippie ka yay.
 
#74 ·
Looked at the specs for the alternator system on the GL500/GL650. The alternator output is RPM dependent and apparently develops max power at 5000 RPM and delivers 252W according to the OEM service manual. After 5000 RPM the output goes down. This is how most motorcycle alternator systems work. The regulator/rectifier (RR) is not engine speed dependent, only monitors the electrical system voltage and compares it to the RR reference voltage of approximately 14.2 VDC. Voltage in the electrical system should not go above this, but if so, only a point or two. If the voltage in the system goes up to 15 VDC as mentioned, there is an issue with the RR, or a component of the electrical system such as the battery. A faulty battery will draw a lot of power such as the 15 VDC mentioned, have had this happen. Doing this for too long a time will damage the RR. The RR will work up to the red line, if not, there is a problem that needs to be found.
 
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#75 ·
Honda says the regulated voltage can be anywhere between 14 and 15V at operating RPM (13V at idle is about what I would expect) in all of the FSMs I've looked at (all normally aspirated CX/GL500/650 plus GL100 and 1100) so I would be very surprised if the Turbos are different.
I would be more concerned if the voltage across the battery is under 14V at 3,000 RPM than if it occasionally reaches 15V.
 
#77 ·
Honda says the regulated voltage can be anywhere between 14 and 15V at operating RPM (13V at idle is about what I would expect) in all of the FSMs I've looked at (all normally aspirated CX/GL500/650 plus GL100 and 1100) so I would be very surprised if the Turbos are different.
I would be more concerned if the voltage across the battery is under 14V at 3,000 RPM than if it occasionally reaches 15V.
The battery’s spec is for 14.5V max. Of all the Hondas I have had (and still do), the charging system is always the weakest point. I never replaced water pumps or even headlights as much as I replaced RRs and alternator coils.
The fact that original RRs allow 15 volts doesn’t make it right. With my 775, the voltage would go even higher than 15V… definitely not recommend..
 
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