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-   -   R80GS; which problems to expect? (https://www.horizonsunlimited.com/hubb/bmw-tech/r80gs-which-problems-to-expect-8361)

motordude 18 Mar 2006 21:11

R80GS; which problems to expect?
 
Hello all,
going from Norway to Oz in 2007. My bike has approx. 60k kms on the clock.
I bought the bike a couple of years back and I did the following:

1. New Valeo starter.
2. Gearbox; turned a Seeger ring groove in the shaft (can`t remember which) and changed all bearings. When the box breaks down, what is it that actually goes wrong?
3. Register chain and damper/slider.
4. Swingarm bearings.

Next on the list is a new driveshaft, although the one I have is OK.
Then new shock absorber.
I have an extra diodeboard and regulator to take along.
I`ll take the engine to bits and put in new valves and cut the seats (+ other stuff if necessary).

So what did I overlook? Any other bits that require attention?

regards

John


fatal 18 Mar 2006 23:54

For the relatively small cost involved it may be worth replacing the valves and springs. I have heard that they may be a weakness in high mileage air cooled boxers. Perhaps the timing chain and tensioner as well, and take a spare starter relay. Good Luck with the trip.

yngveer 19 Mar 2006 21:17

Heisann.

The rotor is a common part that fails after some miles, and if you dont know how your carbs is, get then redone and tuned. This can save you some fuel on a long tripp...

God tur
yngve

Timo 19 Mar 2006 23:04

If you haven't already, take a look over the previous posts - there is lots of good discussion on preparing these bikes for a long trip.

I'd recommend changing the rotor for a solid one-piece rotor (see links for Motorade elektric), and use your existing rotor as a spare.
Brake pads and caliper rebuild.
FULL service.
I'd upgrade to progressive springs in the fork, as well as changing the shock.
New battery?
Add some full wrap 'bark buster' hand/ lever guards.
Make sure you take your bike for good a run down trip after all modifications/ fixes are performed to make sure everything works as you expect.

Enjoy!

Frank Warner 20 Mar 2006 08:05

Take a alternator rotor, they fail more frequently that diode boards or regulators.

Fit a new hall effect sensor. Fit new spark plug caps (5k ohm types) and new spark plug leads (wire type).

I'd take a clutch cable too.

Mombassa 20 Mar 2006 09:44

Timo, the Motorrad rotor is not "solid". It's still a wound rotor. The solid rotor setup is from http://euromotoelectrics.com/

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Kevin

http://www.nohorizons.net

simmo 20 Mar 2006 18:41

Hi John

Make up a travellers gearbox output shaft flange puller and take some of the single use only driveshaft bolts that attach to the flange, you'll need them when you put the gearbox back in! Basically a circular peice of aluminium with a centre bolt to screw down on to the output shaft and four outer bolts to secure it to the flange.

Take a selector return spring and a spare outputshaft oil seal, not to mention the large output shaft bearing, it was hard to find, you will also want a spare gasket for the g/box lid.

Have a lightweight exhaust tool made with a cut out to use as a brace when doing the output shaft flange bolt up to its required zillion pounds of torque

Take spare instrument bulbs, I dont know if yours is the same as the earlier G/S but the charge circuit runs through the generator light bulb on the dash!!! You might only notice when your battery is flat and you think.bugger that bloody light didn't come on 500kms ago when I started it up.....

Harden the valve seats so you dont get valve recession on poor fuel. Put a braided front brake hose on.

Get a cheap rebuildable shock, such as an IKON, Ohlins is total overkill on such a evil handling slug.

If this is a paralever and you are carrying alot of weight, make sure you have a solution to the lower shock mount ripping out from the final drive housing.

Take a tyre repair system, tubes or plugs or whatever and know how to use it.

But when it all stops functioning as mine did for the umpteenth time yesterday at kilometere 900 of a desired 1050, remember that the footpegs on an 84 R80 GS are the same as on a 04 12GS.

At least it wasn't the bloody gearbox again. Thats progress I suppose.

alec



Glynn Roberts 21 Mar 2006 04:17

I agree with all the above advice and modifications - I have over 150,000 miles on my own G/S and some of the above modifications, but I ask you to bear in mind the bike has no idea where it is (eg. darkest India)... at the very MOST you wont do 50,000 kms to OZ, do you really think all the above is nessesary, worth the time and expense for less than 50,000kms?

If you didn't buy all the above you could quit work 6 months earlier !
I think you'll end up a mobile bike garage, carrying too much weight, having no space on the bike, and the hassle of looking after all the spares - security - not free enough to enjoy all parts of the trip.

Not for me I'm more from the minimalist school and sooner spend the money on petrol - travelling light.

Cables,bulbs etc.

New rotor, new shock, new driveshaft. Full service. Finish.

Oh and if you have room, a detense spring for the gearbox...

Timo 21 Mar 2006 12:21

It's a good point... How prepared is enough? Lot's of people have purchased a new enduro of some description and hit the road to glory. However, I think that most would suggest some form of preparation, especially on a 11-17 year old bike with 'known issues'.

Some of my most treasured adventures have been the cause of a breakdown of some sort, but I'd still rather fix what I can up front and at home in my garage - it will still break down when you least expect it!

I'm less sure about the arsenal of spare parts. It seems to me this should be somewhat variable to the availability of parts and/ or mail service where you are going.

simmo 25 Mar 2006 10:57

Some have scoffed at the generator light bulb being a culprit in the flat battery syndrome, others have suggested that as the light goes out when revs increase..assuming all normal..I must be delusional. Others say that it is outrageous to expect the whole charging system to be dependant on one small dash bulb. What stupid company would do that to its bikes...

Well sceptics its true. Although you wont find reference to it in your haynes or clymers, the genereator bulb acts as the exciter for the alternator. This means that the battery will not charge if the filament is broken.

Above 4000rpm the alternator will self excite and the battery will charge, but as you can imagine keeping a BM flat twin above 4000 is not how its ridden generally.

Thanks to BM cycles in Melbourne for the explanation, although it still feels like gobledy gook to me.

Maybe Frank can explain it!


chris 25 Mar 2006 18:31

Check: http://www.horizonsunlimited.com/ubb...ML/000074.html

I now own 3 bikes: A Triumph, a Honda and a Kawasaki.

Having an airhead Beemer is a good way of meeting people, particularly mechanics. If you do search out a mechanic, make sure he's not a BMW mechanic. In my experience they are overpriced/unskilled/dangerous. Jap/no-brand boys were much better.

HTH
ChrisB

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TheBrightStuffDotCom

Timo 25 Mar 2006 23:22

The generator light/ charging system is indeed a funky way of running the charging system. Keep in mind that these bikes where designed back in the 60's, when this technology was more appropriate. What is amazing is that a bike so dated remains a viable option for world travel. I challenge you to go RTW on an early 70's Harley/ Ducati or Honda without similar issues. Of course, why didn't BMW update the bike? Well, as Beemer lore would have it, the K series was supposed to replace the boxers in the mid eighties, but continued popularity of the design and luke warm acceptance of the K bikes led to the boxers being held over until a real replacement could be manufacturer - the Oilheads. BMW did/ does not have a lightning fast development program....

Aside from the design of the charging system which would be expensive and difficult to change, the main problem with this setup is it's dependence on a notoriously weak filament type bulb. You can swap this out for a LED bulb - much more durable. Touratech:

http://www.touratech.de/shop_uk/enter.html

Offers and STD control lamp that replaces all the warning lights with a LED array. It requires a resistor to run the charging system. It is designed for plug in on the R80/100 GS but fitment on a G/S is possible with a bit more cutting and manual wiring.

beddhist 26 Mar 2006 03:24

First, this charging system setup is, or at least was at the time, standard car technology. Dto. for the starter motor. Even the alternator is half a car item.

According to the German Boxer Forum you can put a small resistor in parallel to the bulb. That way the current keeps flowing even if the bulb is dead.

Atwoke 26 Mar 2006 07:42

A truly interesting issue for loads of people...have to check what's in my bike..

Chris, looking forward to discussions in the North http://www.horizonsunlimited.com/ubb/smile.gif...

Grant Johnson 26 Mar 2006 22:54

Quote:

Originally posted by beddhist:
First, this charging system setup is, or at least was at the time, standard car technology. Dto. for the starter motor. Even the alternator is half a car item.

Agreed, common - and I've seen even dumber - like the taillight that was doing the job of the charge bulb on the BMW, and if it blew there was a switch to flick, so you could continue on - Ducati, 1964. I just rode mine with the switch always flicked, cause the taillight burned out regularly! didn't seem to make any difference...

Quote:

Originally posted by beddhist:

According to the German Boxer Forum you can put a small resistor in parallel to the bulb. That way the current keeps flowing even if the bulb is dead.

Sounds like a good one to translate and post here Beddhist! Thanks! http://www.horizonsunlimited.com/ubb/wink.gif

Don't you just love getting volunteered? http://www.horizonsunlimited.com/ubb/biggrin.gif


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Grant Johnson

Seek, and ye shall find.

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One world, Two wheels.
www.HorizonsUnlimited.com


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