Rectifier

Why would you think it was the "rectifier"?? The charge management is all done via a car type alternator and managed via PWM from the ECU

What actually happened ?? Driving along Dash and lights all showing ?

Engine goes into engine breaking mode? Dash stays on or turns off ?

Engine not running when you stop?

Will crank over ?? Sluggish? or as it did when you started the day ??
I think the recovery dude thinks its a standard Jap bike set up Stator rotor and rectifier regulator

Anyway I think you need one of these 16148523697 or to at least get a duff one and make up a bypass lead to carry with you It is likely to happen again!!

My first move would be to look in where the FPC sits in the fuel pump well left side front of the fuel tank assembly

Make sure that there are no nicks in the shaped seal (Marked with the star) and there is no water in the well below?

If there is dry it out and use silicone grease on the seal and connector and try as best you can to keep water out

View attachment 406686
 
Your reasoning sounds very unlikely as you said the bike turned over a few times but wouldn't start. So the battery wasn't immediately flat was it.
I really think you should get this diagnosed but someone competent as you are jumping to conclusions that could end up costing you money that you may not need to spend trying to rule things out.
A new battery won't break the bank anyway, start there.
 
I was drinking along 70mph bike started to cough and loose power. Everything in dash normal with no lights or warnings. I initially thought I’m running out of petrol but dahs shoes half full tank. Pulled into inside lane. And while I twisted throttle there was a sluggish response and it felt as though again it was going to die and seemed very much like an engine running out of petrol.

Fortunately a slip road approaching which I look and as I pulled into it the bike just died. Once I was pulled over I tried to restart. It would try to turn over but I thought omg I’ve ran out of petrol. Opened cap and could here petrol swilling around as I moved bike back and forth.

Someone else on here mentioned it could be the fuel pump controller as you say. I’ll take a look at that today and see if any water in it corrosion
 
I was drinking along 70mph bike started to cough and loose power. Everything in dash normal with no lights or warnings. I initially thought I’m running out of petrol but dahs shoes half full tank. Pulled into inside lane. And while I twisted throttle there was a sluggish response and it felt as though again it was going to die and seemed very much like an engine running out of petrol.

Fortunately a slip road approaching which I look and as I pulled into it the bike just died. Once I was pulled over I tried to restart. It would try to turn over but I thought omg I’ve ran out of petrol. Opened cap and could here petrol swilling around as I moved bike back and forth.

Someone else on here mentioned it could be the fuel pump controller as you say. I’ll take a look at that today and see if any water in it corrosion
Clearly I wasn’t drinking along 😂 that would be illegal but riding. Apologies for typos. R
 
While you have access to it, by pass the controller and this will also tell you if the fuel pump is ok.
The controllers that I have seen fail are on the earlier bikes and have had total failure, these later ones may cause an intermittent fault ?
Fuel pump failure can show as an intermittent fault for a while. ( like running out of petrol).
 
While you have access to it, by pass the controller and this will also tell you if the fuel pump is ok.
The controllers that I have seen fail are on the earlier bikes and have had total failure, these later ones may cause an intermittent fault ?
Fuel pump failure can show as an intermittent fault for a while. ( like running out of petrol).
Thanks Mistacat really helpful mate
 
Surely even a dead battery would not cause any engine to cut out when sunning as the charging system would generate enough power to keep things running. Everything I’ve read seems to say that ie generally once an engine is running the battery don’t do a lot. Hence my worry is still in this a rectifier or alternator issue.

Rob

Wrong assumption
I’ve had more than a few 1200 with knackered batteries that have stopped running.
Why the obsession with the rectifier ? I’ve never had a 1200 with a failed rectifier .
Put the tools down and step away from the bike and do a proper diagnosis instead of scattergun guessing .
 
Just removed petrol tank covers and I can see that the fuel pump controller looks corroded but impossible to tell if the unit it’s self is internally on the way out.

Bike starts and runs currently. This seems an intermittent issue. The fuel pump controller and the fuel pump are both costly items. Any idea how I narrow down the exact fault. Don’t really want to take to BMW as we all know they charge a fortune.

I have a GS 911 diagnostic. Would this tell me the issue if I plugged it in.

Again all help appreciated. I live in North East also open to any recommendations for helpful BM techs.

I have a picture of fuel controller. Not sure how to upload pic to thread.
 
Wrong assumption
I’ve had more than a few 1200 with knackered batteries that have stopped running.
Why the obsession with the rectifier ? I’ve never had a 1200 with a failed rectifier .
Put the tools down and step away from the bike and do a proper diagnosis instead of scattergun guessing .
 
Thankyou. Advice would be helpful. I have tried to diagnose. I’m now onto fuel pump controller. Trying my best to work through it with advice from forum.
 
I have a GS 911 diagnostic. Would this tell me the issue if I plugged it in.

It’s a diagnostic tool, plug it in and find out ., :D

I have a picture of fuel controller. Not sure how to upload pic to thread.

Stop…, how can anyone diagnose a possible intermittent electrical fault from a picture..
 
Wrong assumption
I’ve had more than a few 1200 with knackered batteries that have stopped running.
Why the obsession with the rectifier ? I’ve never had a 1200 with a failed rectifier .
Put the tools down and step away from the bike and do a proper diagnosis instead of scattergun guessing .
It’s a diagnostic tool, plug it in and find out ., :D



Stop…, how can anyone diagnose a possible intermittent electrical fault from a picture..
Cheers. The picture was meant to show the corrosion/watermarks on the component. I do take your point however.
 
The fuel pump controller By-pass cable is a handy thing to carry on the bike as it takes up little room and can be cheap to make if you can find a dead controller.

If it is the fuel pump there are good quality replacements for around £80 , I would avoid the £25 ebay pumps.
 
just removed petrol tank covers and I can see that the fuel pump controller looks corroded but impossible to tell if the unit it’s self is internally on the way out.

Check the well below the controller!! and the connector for water / water ingress

I have a GS 911 diagnostic. Would this tell me the issue if I plugged it in.

No it will not! It won't even help diagnosis in this case, the Fuel pump controller has no monitor and there is no fuel pressure sensor to say low pressure and as far as the GS 911 is concerned it "sees" the controller but has no idea what it is doing after the connection if it pumps or is seized for example

I have seen quite a few fail intermittently and then just give up So be warned Even if you dry it out!

If there is ANY water in the part below the controller Just replace it and make up a lead to carry with you in case it ever happens again
 
Check the well below the controller!! and the connector for water / water ingress

I have a GS 911 diagnostic. Would this tell me the issue if I plugged it in.

No it will not! It won't even help diagnosis in this case, the Fuel pump controller has no monitor and there is no fuel pressure sensor to say low pressure and as far as the GS 911 is concerned it "sees" the controller but has no idea what it is doing after the connection if it pumps or is seized for example

I have seen quite a few fail intermittently and then just give up So be warned Even if you dry it out!

If there is ANY water in the part below the controller Just replace it and make up a lead to carry with you in case it ever happens again
Thanks you
 
Check the well below the controller!! and the connector for water / water ingress

I have a GS 911 diagnostic. Would this tell me the issue if I plugged it in.

No it will not! It won't even help diagnosis in this case, the Fuel pump controller has no monitor and there is no fuel pressure sensor to say low pressure and as far as the GS 911 is concerned it "sees" the controller but has no idea what it is doing after the connection if it pumps or is seized for example

I have seen quite a few fail intermittently and then just give up So be warned Even if you dry it out!

If there is ANY water in the part below the controller Just replace it and make up a lead to carry with you in case it ever happens again


I’m sure it will flag up one of those “failed however many times previously, but not failed now” faults ??

I’ve a few fuel pump controllers on the shelf, ready for use making bypass leads :D
 
Last edited:
I’m sure it will flag up one of those “failed however many times previously, but not failed now” faults ??

I’ve a few fuel pump controllers on the shelf, ready for use making bypass leads :D
I could take it to my local BMW dealer, relive my pants, bend over and get ready for the inevitable pain, including a re mortgage just to get it diagnosed incorrectly.

Battery is now fully charged. Tested with multi meter and seems to be holding its own under start and load. I’ll see how this goes for now.
 
I could take it to my local BMW dealer, relive my pants, bend over and get ready for the inevitable pain, including a re mortgage just to get it diagnosed incorrectly.

Battery is now fully charged. Tested with multi meter and seems to be holding its own under start and load. I’ll see how this goes for now.

Have you plugged in your GS911 diagnostic reader yet ?
Or are we still guessing ?
 


Back
Top Bottom