lesson learned

[stevenrankin]

After a bad accident with my 78 R100RS, it sat in boxes for a few years. I was riding my 84 R80RT most of the time anyway.
So, I finally had the RS rebuilt in time to get to the RS rally. When I had it rebuilt, I added heated hand grips, I have them on the R80 from the factory and like them.

So now, the RS is on the road but I am riding the RT 90% of the time. I hit 200K with the RT this past summer and decided hey, time to put miles on the RS.

I am riding one sunny but cold day and the generator/charge light comes on. As it was, it was closer to go to my friend's airhead shop than it was to get home on the battery.

Once at the shop we start troubleshooting and discover the stator winding solder joints and insulation on them had melted/burned off.

Moral of the story; With an old charging system, don't overstrain it with additional stuff. Granted, heated grips should have worked fine with the stock system and in fact a solder joint may have been bad and I never caught it before. Still, all three solder connections were melted.

Crazy eh? The past few rides with the RS saw me using the heated grips a lot whereas I had only tested them when first installed for a few minutes to see if they worked.

So, could there be another cause? We are looking over everything and I am upgrading to an Omega system so I can use my electric jacket pants and grips. Cheers all St.

 

[RPGR90s]

After a bad accident with my 78 R100RS, it sat in boxes for a few years. I was riding my 84 R80RT most of the time anyway.
So, I finally had the RS rebuilt in time to get to the RS rally. When I had it rebuilt, I added heated hand grips, I have them on the R80 from the factory and like them.

So now, the RS is on the road but I am riding the RT 90% of the time. I hit 200K with the RT this past summer and decided hey, time to put miles on the RS.

I am riding one sunny but cold day and the generator/charge light comes on. As it was, it was closer to go to my friend's airhead shop than it was to get home on the battery.

Once at the shop we start troubleshooting and discover the stator winding solder joints and insulation on them had melted/burned off.

Moral of the story; With an old charging system, don't overstrain it with additional stuff. Granted, heated grips should have worked fine with the stock system and in fact a solder joint may have been bad and I never caught it before. Still, all three solder connections were melted.

Crazy eh? The past few rides with the RS saw me using the heated grips a lot whereas I had only tested them when first installed for a few minutes to see if they worked.

So, could there be another cause? We are looking over everything and I am upgrading to an Omega system so I can use my electric jacket pants and grips. Cheers all St.

I think the key here is that your entire system was older, and not necessarily a design or overloading problem. Remember that BMW installed heated grips on Airhead's right up to 1995 (My brand new 1993 R100RT had them) and the charging system was the same 280 watt output.

I put 60k on that RT and in Michigan, I used the grips, and a heated jacket for most of my spring and late fall riding. Never had a charging issue.

Upgrading to the Omega system is a good idea, but remember that if you're using the stock 42 year old wiring harness, well.............

RPGR90s

 

[stevenrankin]

New system and other musings

If I recall from when I installed the Omega system on my RT, I got a new harness from the volt regulator to the alternator, pretty much the important stuff.

I agree, an old system, not sure if the solder joints were ever soldered properly in the first place.

Second lesson learned with this bike pertains to beauty hides a lot of sins.

A pretty looking, supposed low milage bike, in outwardly good condition, has proved to be a money grabber due to hidden flaws mechanical and now electrical.

I am lucky it is not my dogs body bike. Until this year, I have not ridden it much since I bought it in 98, was hit by a car in 2000, it sat in bins till 16, then rebuilt in 16 and 17. I have not put many miles on it since original purchase and since rebuild but, since the rebuild, it has been showing an ugly side.

Just had to have the valve guides done and new bore job, rings, rebuild due to it sucking a lot of oil.

So, in 98 I bought this pretty supposed low mileage RS, Rode it a couple of thousand miles, got whacked, it sat in bins, got put back together, looks pretty, but, come to find out it needs a lot of work for a supposed less than 40K bike.

Oh well, it could be worse. At least, I can do most of the work myself or I have an airhead shop nearby that does very good work and is reasonably priced. St.

 

[pauls1150]

I forget if 1978 was affected, but speaking of melted solder joints, maybe now is a good time to inspect the diode board... Many units didn't have the diode's leads bent over on to the board prior to soldering - this makes the connection entirely dependent on the mechanical strength and hopefully low resistance of the solder - and some boards wound up with melted solder (wrong type of solder?).

 

[20774]

Snowbum discusses the Wehrle boards with poor solder near the top of this page:

https://bmwmotorcycletech.info/diodebds&grdgwires.htm

 

[stevenrankin]

Diode board

Oh yeah, I remember the long running and perhaps still running diode board saga.

Safe to say, the Omega system I have ordered comes with a new more robust diode board solid mounts, as well as an electronic voltage regulator.

Yep, as I said, beauty can hide many sins. I just hope I have them sorted out now so I can ride the bike without trouble.

Could be worse, I could have spent 30K on a new BMW R1250RT and at 4K miles had a cam go out only to have the bike sit in the shop for 8 weeks or so. Then, I would be real unhappy. With two 30 year plus bikes with lots of miles, I expect things. St.

 

[RPGR90s]

lessons learned

Oh yeah, I remember the long running and perhaps still running diode board saga.

Safe to say, the Omega system I have ordered comes with a new more robust diode board solid mounts, as well as an electronic voltage regulator.

Yep, as I said, beauty can hide many sins. I just hope I have them sorted out now so I can ride the bike without trouble.

Could be worse, I could have spent 30K on a new BMW R1250RT and at 4K miles had a cam go out only to have the bike sit in the shop for 8 weeks or so. Then, I would be real unhappy. With two 30 year plus bikes with lots of miles, I expect things. St.

Couldn't agree more Steve, Its hard for me to justify 30k on the new RT when my 110k R1150RT just purrs along with no issues. And my high miler R90s gets ridden daily. So simple and so reliable.