Mosfet Regulator for ST1100?

[BosunChairman]

Hi guys. My bike was charging around 15v at 3000rpm and quite probably cooked the last battery. So I bought a new yuasa battery and one those mosfet regulator super kits from (Roadster Cycle) and after much trial and error I managed to squeeze it in the original RR's location. Very complete kit btw. The new one is quite a bit wider than the stock one so it's a tight fit. Not much to hook it up. Of course I cut the stator wires and soldered them to the supplied wires and hooked up the other two wires to the battery and I find out it isn't charging at all. The original connector with the other wires was put aside and taped up like the instructions said. Has anyone tried one of these for an ST1100 and if so what problems did you come across. Of course the solutions to those problems. I also tested it using the roadster cycle video and it checked out fine.I feel like going back to the stocker and putting the new one in my Vfr instead. Thanks in advance.

 

[DeanR]

Part number? Have not heard of these.

Hi guys. My bike was charging around 15v at 3000rpm and quite probably cooked the last battery. So I bought a new yuasa battery and one those mosfet regulator super kits from (Roadster Cycle) and after much trial and error I managed to squeeze it in the original RR's location. Very complete kit btw. The new one is quite a bit wider than the stock one so it's a tight fit. Not much to hook it up. Of course I cut the stator wires and soldered them to the supplied wires and hooked up the other two wires to the battery's dead I find out it isn't charging at all. Has anyone tried one of these for an ST1100 and if so what problems did you come across. Of course the solutions to those problems. I also tested it using the roadster cycle video and it checked out fine. I feel like going back to the stocker and putting the new one in my Vfr instead. Thanks in advance.

 

[kiltman]

15 volts for a pre 1996 ST1100 is considered normal. I would check all connectors from the alternator to make sure they are clean and tight. They would be the red connector with three yellow wires, the connector to the VRR, the black connector with the white and black wires from the alternator and the red connector to the main relay. These are all on the left side of the bike near the VRR

 

[BosunChairman]

I checked those before I bought the new Vrr. All were good. The previous battery which was supposed to be new turned up dead after an all day ride so I bought another. Maybe the previous owner ruined the battery. I had no reason to check voltages before that. Bike ran great. I just don't want to have that issue with the new battery. I haven't heard of anyone using a mosfet Vrr in an st1100. I guess I should have researched this a little more. Very common upgrade for a lot of other bikes like VFRs. Maybe I'll just use it in my VFR 800. They are known for regulator problems and stator problems.

 

[BosunChairman]

The model is a Shindegen mosfet regulator FH020AA. They are used in Yamaha R1s

 

[DeanR]

Maybe I'll just use it in my VFR 800

So you did or did not fit it in the 1100?

 

[BosunChairman]

So you did or did not fit it in the 1100?

I did mount it and hooked it up. Started it up and got 12 volts. In other words it wasn't charging at all. I'm finding out that nobody's been trying these kinds of Regulators on ST1100s. A lot of people with different bikes are using them with great success. Lot of Honda bikes too.

 

[Al st1100]

sounds like the alt is out--

 

[ST1100Y]

First we would need to know what type/year of alternator is presently installed...
The pre '95 oil-cooled 26A unit has 3 mains-windings (3-phase armature) and one control-winding (black/white, control voltage input thus no slip-rings).
The VRR rectifies the 3-phase output to DC, detects/monitors the voltage and raises/lowers the control voltage accordingly to keep the DC side at 12.6~15.0V.

The air-cooled 40A post '96 unit however, has slip-rings and an on-board VRR, thus only 2 cables attached: DC out, ign in ("activating")

 

[BosunChairman]

First we would need to know what type/year of alternator is presently installed...
The pre '95 oil-cooled 26A unit has 3 mains-windings (3-phase armature) and one control-winding (black/white, control voltage input thus no slip-rings).
The VRR rectifies the 3-phase output to DC, detects/monitors the voltage and raises/lowers the control voltage accordingly to keep the DC side at 12.6~15.0V.

The air-cooled 40A post '96 unit however, has slip-rings and an on-board VRR, thus only 2 cables attached: DC out, ign in ("activating")

As far as I know it's the original alternator. It's a 1990 ST.

 

[kiltman]

As far as I know it's the original alternator. It's a 1990 ST.

Just curious, what's the last three digits of your serial # You may have the oldest ST

 

[BosunChairman]

Just curious, what's the last three digits of your serial # You may have the oldest ST

I think it's 008. The 8th ST1100 to come into Canada. We got them a year before the states.

 

[kiltman]

I think it's 008. The 8th ST1100 to come into Canada. We got them a year before the states.

I had #065, I know the history. They imported 225 that year. There's still a number of them on the road. Good to know

 

[Bush]

Originally Posted by ST1100Y
First we would need to know what type/year of alternator is presently installed...
The pre '95 oil-cooled 26A unit has 3 mains-windings (3-phase armature) and one control-winding (black/white, control voltage input thus no slip-rings).
The VRR rectifies the 3-phase output to DC, detects/monitors the voltage and raises/lowers the control voltage accordingly to keep the DC side at 12.6~15.0V.

The air-cooled 40A post '96 unit however, has slip-rings and an on-board VRR, thus only 2 cables attached: DC out, ign in ("activating")
As far as I know it's the original alternator. It's a 1990 ST.

As far as I know it's the original alternator. It's a 1990 ST.

If you have the OEM alt, it has a smooth, totally enclosed outer case, since it is oil cooled. If your alt was upgraded at some point to the 40 amp version, it will look just like the alt in your car, with an open, vented case, since it is air cooled.

 

[BosunChairman]

If you have the OEM alt, it has a smooth, totally enclosed outer case, since it is oil cooled. If your alt was upgraded at some point to the 40 amp version, it will look just like the alt in your car, with an open, vented case, since it is air cooled.

The alternator is smooth. It's an original 28a unit. I'm thinking about just reattaching the original Vrr. I hope nothing changed if I go back to it. I don't remember which of the 3 yellow wires went where in the connector. I hoping it won't make a difference but with my luck I probably fried the alternator somehow. I just don't like the idea of it charging the battery at 15v even if it says that's normal. It's not normal in in pretty much every other vehicle. I won't have any confidence in taking the bike on a long ride unless I pack an extra battery with me.

 

[kiltman]

Last summer I rode from Stratford along the Canadian route to Banff then back to Moose Jaw. Rode around the province of Saskatchewan then rode back to the Sault via the States, went to On-STock then Rode home and rode another 3k in Ontario for a total of 16k km, all the time my 1990 was charging in the neighbourhood of 14.7-14.9 volts. The year before I was on PEI and rode 10K on the island alone still pumping that voltage. I had a voltmeter, and for the most part was judicious on my electrical accessories. The wiring schematic will indicate which wire goes where on the VRR. Once you have the black and white wire sorted I don't think it matters which yellow wire is connected only that it's for a yellow wire terminal.

 

[BosunChairman]

Last summer I rode from Stratford along the Canadian route to Banff then back to Moose Jaw. Rode around the province of Saskatchewan then rode back to the Sault via the States, went to On-STock then Rode home and rode another 3k in Ontario for a total of 16k km, all the time my 1990 was charging in the neighbourhood of 14.7-14.9 volts. The year before I was on PEI and rode 10K on the island alone still pumping that voltage. I had a voltmeter, and for the most part was judicious on my electrical accessories. The wiring schematic will indicate which wire goes where on the VRR. Once you have the black and white wire sorted I don't think it matters which yellow wire is connected only that it's for a yellow wire terminal.

I put the original VRR back in. Mine charges closer to 15v unlike yours. I don't think that mosfet VRR is cut out for my bike. With all the charging issues ST1100 owners have been dealing with over the years on the older version I'm sure someone would have tried a regulator like the one I bought but I can't find any example. I might look for a stock VRR on eBay. Might get a voltmeter for it as well. I'm thinking about a VRR from Rick's electric too. Cheaper than a stocker and possibly better. Appreciate your advice btw. Also I'm planning on taking it to Ontario this summer. Trucking it to Thunder Bay and getting it on the road from there. Wife's going to drive the truck. Heading to the Bruce peninsula for a couple weeks. Hope this bike doesn't let me down.

 

[Bush]

Please cover your ST while it is being trucked to Ontario. It is only Harley's that are normally seen in the back of trucks, after they have broken down, so we don't want a bad impression of our beloved ST's to be implied.

You know you'll miss some of the best riding in the stretch from Winnipeg to Thunder Bay?

 

[BosunChairman]

Please cover your ST while it is being trucked to Ontario. It is only Harley's that are normally seen in the back of trucks, after they have broken down, so we don't want a bad impression of our beloved ST's to be implied.

You know you'll miss some of the best riding in the stretch from Winnipeg to Thunder Bay?

Not so sure about the stretch from Winnipeg to Thunder Bay. It's nice around Kenora but a little boring after that. It depends on the weather. I mainly want to ride from Thunder Bay. That's when it gets nice as far as I'm concerned. Drove out there last year with my xr650l in the back of the truck. It's hard to keep up with a four wheeler on a highway with that for long periods. I go out to BC as well with the xr650l and another bike in my truck. This year I bought a low mile 2001 VFR 800 with the money from selling my other bike and I'm really looking forward to riding around southern BC with that. Nice having a truck. One trip is with the wife and the other one is for me to see my family and ride with my brother. He has a 2002 VFR. Had a 2008 KTM Superduke for the last three years. That's a bike that you need a truck for. Let me down 2 out of the last 3 years. Absolute blast but not trustworthy.

 

[Paul the Pan]

15 volts for a pre 1996 ST1100 is considered normal. I would check all connectors from the alternator to make sure they are clean and tight. They would be the red connector with three yellow wires, the connector to the VRR, the black connector with the white and black wires from the alternator and the red connector to the main relay. These are all on the left side of the bike near the VRR

Hi
Sorry for the thread resurrection, but this was the first thread that I could find that mentioned the red connector with the three yellow wires.
I've just done the "red wire bypass", and I saw during my research that the red connector with the three yellow wires is also prone to corrosion and burning. Apologies for sounding ignorant, but where is this connector located? The bike is a '91.