Thoughts on a 1975 BMW R90/6?

[mfp4073]

clutch may improve with riding, remember its probably got a bit of surface rust/sheen on it and will be a little grabby.

suspect the oil on boots is from the push rod tub seals. They are rubber and at the base of the pushrod tubes on either side. Old rubber= fail

Dont know about the cancel buzzer, but mine doesnt have one.

Tach and speedo just need to be lubed and will probably smooth out for 95% of the time.

No kill, gotta turn it off with the key!

side stand is spring loaded and takes a little getting used to. Its probably not in the factory position and bent some from years of use. Stand should not fold up if the bikes weight is on it.

Tranny, fresh gear oil will make the shifts better. Its a very clunky tranny to begin with. I have found that if it gets a little low on tranny fluid or its needing fresh then it will be harder to shift.


ENJOY IT! You will grow to love your ugly duckling

[Canuman]

Originally Posted by QCDStick

A few things I forgot (doh!)

The turn signal had a buzzer to remind you the turn signal was on. I found it loud, and rather annoying. I'm GUESSING this is an aftermarket deal? Would like to know for sure before I disable / remove it. The indicators on the cluster are notice enough for me and I'm used to checking the gauges.

The Tach and Speedo needles would float and bounce around quite a bit as well, guessing this is normal.

There seems to be no kill switch? The turn signals are where I expected the starter to be, and the starter where the kill switch should be. Pressing other things, I didn't find a kill switch. Would be handy to have one especially since the ignition isn't in the most accessible place.

The kickstand is unbelievable picky on how you park the bike, and spring loaded to fold up once you stand the bike up (which is OK I guess as long as it doesn't lead to bad habits on other bikes!). Do people just end up using the center stand all the time? I mean, if the road has much of a crown, you feel like the bike could go over the far side. If you are parked in ANY way down hill, it feels like the stand wants to fold up (aided by the spring) pulling the bike forward and off the stand. I didn't have any problems, but when I stopped I had to try a half dozen places / angles to find one that didn't leave me feeling like the bike was teetering on disaster. And I live in Iowa for goodness sake, It's not like we have much for hills around here. For one photo op, I actually had to do a U turn to park the bike facing up hill to take a picture (not a big hill, nearly flat!) and then the slight crown on the road still left it not feeling very solid. Most difficult time I've ever had with any bike with a kickstand. Do you guys plan your parking days in advance?

Oh, yes, you are discovering the beauty of Old German. The factory sidestand sucked; most replaced it with a Brown. Yes, the centerstand is where the bike wants to be. If you leave it for more than an hour or two on the sidestand, oil drains down into those aircraft cylinder heads and smokes like a bustard on start.

As to the turn signals, simply remember this mnemonic: It's LEFT UP to me to figure out this DOWN RIGHT silly system.

There is a kill switch.

That has to be one of the worst fairings and most awful seats I've ever seen. That being said, take her in hand and make a lady of her once again. You'll be glad you did.

If you can score the Matchless, I'd be all over that, also.

[disston]

Congratulations. Sounds like a great Airhead.

They are noisy when shifting. Takes some getting used to. Most Airhead riders use "pre-shifting" and say it helps. Before the clutch is pulled in the toe is lifted just enough to remove free play then the shift is performed the standard way. Another technique is to shift with out using the clutch. It is allowed and works better once you get the hang of it.

There should be a kill switch. Sounds like you have a non standard right hand control? The kill switch is a red toggle on the right? Maybe your Grand Dad knows what happened to it.

The side stand and the center stand are more quirky features of the Airheads. There are after market options. The Reynolds Ride Off Center Stands are no longer made I believe but show up at flea markets and such. Probably not really worth the money these days for the Reynolds. But there is a good option for the side stand and it is still made. It is the Brown Side Stand. Also a couple of others are still made but I think the Brown is the most popular.

The bags sound like Krauser's but the wiring does not sound standard. Maybe somebody added some lights?

As far as modifying the front brake there are volumes written on this subject. The handle bar MC is a good beginning. Changing to another style caliper gets involved and is not mentioned often on these forums.

[mfp4073]

Kill switch, just remembered that mine is an early 74/6 with /5 controls and they added one with the new controls

[WRC51]

Wow, you are a lucky guy. To have something like that handed down may not seem like much to some but Iam sure your Grandfather loves/loved that bike. In the pictures the bike really looks to be in nice shape, I will agree the Vetter fairing does not seem to blend with the style of the bike. Very nice.

[QCDStick]

Originally Posted by WRC51

Wow, you are a lucky guy. To have something like that handed down may not seem like much to some but Iam sure your Grandfather loves/loved that bike.

There is no doubt. He's had it for 16 years, but I found out he lusted after one for a long long time before he was able to own one.

I still remember the first time I was up there after he got the bike, I would have been 12 at the time. He would take me on rides starting when I was so little I had to sit on the tank. I can't remember what the bikes were, mostly his Virago's I think. But I do know once he finally got the beemer, I really can't remember him riding anything else. Not to say he didn't, but there is no doubt he loves that bike.

[Boojum]

My 75 R90 /6............. I really like cruising around town on this bike. .....................




Boojum

[More_Miles]

Originally Posted by QCDStick

Engine:
He mentioned before I took off that it uses a bit of oil, and to check it before setting out. Well, I can tell you a good portion of it ended up on top of my boots. How he had not noticed this, I don't know. Maybe it just came up this year? In any case, seems to be coming from the head gasket, on the front side of the engine, right near the exhaust header. Same place on both sides, so I'm assuming this is a common thing? He has the owners manual, and a service manual so we looked it up. It does mention torquing these bolts every 5k miles as part of servicing, I think to 25-28 ft/lbs (although the wording in the service manual is seriously weird on this... I think it says "25 + 2.8"?) He had done this maybe once in the 16 years he's had the bike so I'm guessing they just worked loose on both sides. The question is, will tightening them up fix the issue? Or will the head gasket need replacing at this point, or worse... has something warped due to them being loose?

It could be the valve cover gaskets. My R100 did that on the left side. I could never get it to stop, until I doubled up on the gaskets. If it's in a spot outboard of the exhaust pipe, that's it.

Originally Posted by QCDStick

Clutch / Transmission:
- To say that it doesn't engage smoothly is an understatement. It's pretty much on or off. Makes low speed maneuvering difficult since you can't keep the revs up because when it grabs you shoot ahead 7'. Keeping the revs way down (just a tinge off idle) works much smoother, but I very very nearly stalled it more than once doing that. I was a lot better at it by the end of the ride so I could learn it, but it just didn't feel right to me. Is this normal?
- Also, even when I was sure I had the clutch pulled in as far as it would go, I would occasionally get gear chatter when changing gears. Had to be sure to really be deliberate with my punch of the lever with the clutch lever touching the bars, especially going 2-3 and 3-2 or it would grind the gears. Thinking back, I was not really attempting to rev-match though, perhaps I can't get away with as much on these bikes as what I'm used to with the really light quick revving motors and newer transmission designs. Seems some adjustment could be in order here or is that just how they are?
- An additional concern, once the bike was warm engaging the clutch on shifts was accompanied by a "shiiink" noise, possibly metallic in sound. Seemed to get worse as the ride went on, and was not present at all to begin with. Pretty sure this is also not normal, it was pretty prevalent at times. Also a faint rattle in neutral when warm, which I believe is perfectly normal.

I'll second the suggestion that the clutch may be "sticky" and to lube the splines. Also, you would be amazed at what a difference fresh gear oil in a transmission can do. That being said, the Getrag transmissions are known as "crash boxes" for a reason. Much like shifting an old tractor. All part of the charm old son.

I'll also add that you should expect more oil seeps from any aged gasket. I'm replacing as needed every gasket and rubber bit on my R100RT. On the bright side, as I like to tell me "must-be-cleaned-and-waxed-never-ride-when-it-might-rain-American-Iron" riding co-workers, rainstorms also double as bike washes, and the oil leaks mean I don't need to worry about the bike rusting!

Enjoy the old BMW. They are the consummate gentlemen of the motorcycling world.

[QCDStick]

Originally Posted by More_Miles

It could be the valve cover gaskets. My R100 did that on the left side. I could never get it to stop, until I doubled up on the gaskets. If it's in a spot outboard of the exhaust pipe, that's it.

Unfortunately, it looks like you can trace the oil pretty clearly to the head gasket area. Just inboard of the pipe, on the front of the motor seems to be the source. Valve cover gaskets seem to be OK, though I'll probably replace them anyway since it looks like I'll be in there.

Originally Posted by More_Miles

I'll second the suggestion that the clutch may be "sticky" and to lube the splines. Also, you would be amazed at what a difference fresh gear oil in a transmission can do. That being said, the Getrag transmissions are known as "crash boxes" for a reason. Much like shifting an old tractor. All part of the charm old son.

I'll also add that you should expect more oil seeps from any aged gasket. I'm replacing as needed every gasket and rubber bit on my R100RT. On the bright side, as I like to tell me "must-be-cleaned-and-waxed-never-ride-when-it-might-rain-American-Iron" riding co-workers, rainstorms also double as bike washes, and the oil leaks mean I don't need to worry about the bike rusting!

Enjoy the old BMW. They are the consummate gentlemen of the motorcycling world.

I most certainly will enjoy it! I don't mind any of the quirks per say, but not being familiar with these bikes it is hard to know what is a quirk and what is a potential problem!

[sebastianhammer]

Originally Posted by Boojum

My 75 R90 /6............. I really like cruising around town on this bike. .....................
Boojum

That's a very pretty specimen. Speaking as a very new airhead rider myself, I have to say what astonished me the most has been how my 77 R100/7 feels and sounds on the highway. In town, I feel vaguely conspicuous with my sewing-machine valves (they save lives) and the amazing sounds the gearbox makes when I forget to preload the shifter. But on the highway.... when you settle down for the cruise at 55-60 in fourth, the engine just sounds so... contented. Like THIS was the sweet spot they designed it for.

Had my first freeway rides this past weekend. At 70 or so, in fifth, I found I could barely hear the engine over the wind -- just a distant, comforting hum. Nice.

[lmyamen]

My R90/6 working through just a few small issues and it should be perfect. Did the restore over this winter..Just put some love into the bike and you will not regret it!

What is looked like when I bought it.



After 4 months of work this is what I ended up with!

[More_Miles]

Originally Posted by QCDStick

Unfortunately, it looks like you can trace the oil pretty clearly to the head gasket area. Just inboard of the pipe, on the front of the motor seems to be the source. Valve cover gaskets seem to be OK, though I'll probably replace them anyway since it looks like I'll be in there.

I'll let a more experienced Airhead wrench/guru chime in here, but it sounds like the head gasket is shot where top end lubricating oil comes through the channels in the cylinder. Head gaskets aren't THAT expensive. But buy the damned exhaust nut wrench and a bunch of penetrating oil. You'll need the wrench to fit those finned nuts and the act of having the penetrating oil will mean the nuts won't be seized/galled to the threads on the head. BTW, there is a right way/wrong way to put them on. Can't remember off the top of my head which is which.

Which brings to mind, I'd suggest asking your grandfather if he has any of the special tools like the exhaust nut wrench or any of the other myriad of "special/modified" tools for working on the bike. They aren't hard to source, but if he already has them, well, no sense in breaking up the set.

Originally Posted by QCDStick

I most certainly will enjoy it! I don't mind any of the quirks per say, but not being familiar with these bikes it is hard to know what is a quirk and what is a potential problem!

One "quirk" I'd suggest you nip quick, especially considering the age and recent usage history, are the front and back wheel bearings. They are automotive style wheel bearings and unlike modern motorcycles, are DESIGNED to be serviced. Disassemble them, clean them, inspect them, reset the bearing pre-load if you're anal, obsess over it if you're super anal, pack them with fresh grease, and put new seals in them. Figure on doing this every couple of tire changes. Spun inner journals welded to the axle isn't fun. DAMHIK.... Spun races and destroyed hubs is even less fun.

The bike will drive you to distraction with things like the electrical system (what were they THINKING? Taking lessons from Lucas?) to the side stand (what were they THINKING? Way out under the cylinder so you can't SEE it?) to the centre stand (what were they THINKING? Do you see a pattern developing here?) But I must say, until I got the airhead, I never had a bike that made me want to throw a leg over and strike out for California from New Brunswick/Maine just because...

[disston]

Your Grandfather should have some tools especially the finned exhaust nut tool. Every Airhead rider has to start with getting this tool. Well almost every one. But you will use this tool again and again. So if Granddad doesn't have the tool there are several sources and thru the years there have been many versions of this tool. We will advise, but right now there is an original one on Ebay that has not been bid up yet. These go for a pretty penny sometimes. I don't want to tell you what it might be worth they are sometimes over priced I think. But I do like the original heavy BMW tool.

http://www.ebay.com/itm/270955014898...84.m1423.l2649

[QCDStick]

My grandpa does not have the tool. I specifically remember him mentioning taking it to a guy he knew when he needed that. I checked out the Ebay thing, but seems someone else has a relativly high max bid already on the item. Not sure how much I should pay for it? As it sits now, still outbid and it's 30 bucks shipped right now.

[disston]

If it goes no higher then somebody got a good deal but no telling how high it might go. I can tell you I've seen these sell for over a hunnert on Ebay. I do think that is too much to pay for most people. They might still be available but I haven't seen any other than the auctions for some time. I think the last one I saw new was still 70 or 80 bucks but I'm not sure about that.

I don't even remember what I paid for mine 30 years ago. But I still have it.

At this point if you wanted to try and win this item don't bid any more but "snipe" it. I use a service called Gixen. You can find them with Google easy enough.

That wrench is the cast iron one. There is also a cast Aluminum one that I don't have but think they look OK. Max BMW sells the Aluminum one pretty cheap;

http://www.maxbmwmotorcycles.com/fic...HAUST%20WRENCH

And there is one sold by Cycle Works that works with a half inch breaker bar.

http://www.cycleworks.net/index.php?...roducts_id=346

I think most recommend the Cycle Works wrench and it also has the big advantage of being small enough and light enough to sometimes be carried on the bike.