89 R100RT Electrical System Questions

[Scarletswirl]

Background. I am doing a partial restoration of an 89 monolever RT. It came equipped with radio, which is an abomination, so I removed it and reconnected the harness. Then I checked that everything worked, including the starter. It does work but I did the test with the spark plugs removed and forgot to ground the wires (Yes, I'm still kicking myself for it!). Now the questions:
1. What components were/might be damaged by my stupidity? (I checked the coil, all resistances are spot-on. The spark plugs spark-I tested them in the dark with the body grounded this time. Should I expect the ignition module to be suspect? It's the one ending in 277, but the writing is in white, not turquoise).
2. Since the fairing is off, I looked behind the front cover with the idea of replacing the diode board rubber mounts. I found out that one of the previous owners already did that, and replaced the original board with an "Emerald Island" which is the same Beemershop (Ted Porter) sells. So probably better than ok. The 'bean can' was also replaced with one made by Motorrad Elektrik, marked 'Alpha Ignition System'. Does anyone have any experience with this product?
3. The recommended Bosch plug for my bike is the W7DC. The NGK equivalent of the Bosch W7DC is the BP6ES...according to some. Yet some sources recommend the BP7ES. Is one better than the other? I tend to ride mostly at 3000 rpm and up if that helps.
Thanks,
Marc

 

[20774]

As far as potential damage, I think you would only know for sure if the bike didn't start and/or charge at this point. Sounds like the basic measurements are OK. I'd press on and just keep this in the back of your mind. When you begin to notice some kind of change, then investigate further.

Snowbum has a cross reference chart for plugs...he lists that the BP6ES is the correct replacement plug:

https://bmwmotorcycletech.info/sparkplugs.htm

Again, just keep with what you have and begin to notice any changes. As for the Alpha, Snowbum writes about various aftermarket ignitions here:

https://bmwmotorcycletech.info/Ignition.htm

 

[stevenrankin]

No worries

If the bike is running well, charging well, then you have no worries. Just because you ran it without the spark plugs grounded does not mean instant problem. There IS a potential to pop the ignition module under the gas tank if the plugs are not properly grounded. So it is not a good thing to do as you have learned.

All the components you have on the bike are good quality and will last a long time. I have the alpha ignition system on my bike for 30K miles now with no problem. Of course, I really didn't have a problem with the stock system, in a moment of weak thinking I changed it over to the Alpha system. To be honest, I don't notice any change in performance.

As for the aftermarket diode board, there were problems with early and some years of BMW stock boards. I have a replacement board in my bike only because I upgraded from stock system to a higher output system due to my using a lot of juice for electric clothing.

Again in 30K I have never had a problem with the replacement parts and I did not have any problems with the stock parts for 170K miles.

Ted Porter is a good guy to deal with, I have purchased from him and been very happy.

So enjoy the bike, Cheers, St.

 

[Scarletswirl]

Thanks for the reassurance

I'll know whether it runs when the gas tank comes back from being painted, but thanks to both of you for your thoughts and suggestions.