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Looking to buy an Airhead R90S - first time buyer

Bayou
Posts: 14
Joined: Sat Feb 11, 2023 7:55 pm
Location: Bay Area, California

Looking to buy an Airhead R90S - first time buyer

Post by Bayou »

Hello All,
This is my first post. Apologies for asking the same rookie buyer questions you get all the time.

Airhead bug bit me couple of months ago. I’ve been learning about Airheads and looking for one.

A R90S has surfaced quite close to where I live, asking $5k. It’s all stock with only 1k miles on it from what I gather. The current owner, a big-time antique car restorer (it was a treat to look at so many old cars restored) bought it from his friend, the first owner, over 25 years ago and it has sat indoors since. He is downsizing his collection due to health issues.

The good:
  • Red color – paint is exceptionally good
  • Overall, the bike is in quite a decent shape
  • Both the front brake discs are smooth – no ridges, no bumps,
  • Owners says the carbs were upgraded to Bing from Delorto by the dealer at the time of purchase – don’t know if it is good or bad or doesn’t matter
  • New tires, new battery, has original toolkit
  • Carbs have been rebuilt, the engine fires up at the first press but idling is quite rough, Tacho jumps between 2k and 3k RPM
  • Left and right indicators work
  • Break light works when the foot pedal is pressed but doesn’t when the front brake lever is pressed. Parking light turns on but headlight doesn’t
The bad/ concerning:
  • Reasons for rough idle?
  • Corbin seat is flaking/withering, the sponge is hard to touch, needs to be replaced
  • No side stand, no saddlebags/panniers (I want them though)
  • Front wheel is plenty stiff. I had to try hard to get it to turn 30 degrees. Don’t know if the brakes are jammed or the bearings or incorrectly mounted when the tire was replaced
  • Same story with the Clutch lever, very hard to press
  • The bike is quite loud, not the soft “pukka”, “pukka” sound Airheads are famous for, and smoky too (perhaps due to oil added to lube the pistons to get it to start?). Tail end of the muffler looks a bit different (see last photo). Louder mufflers were an option?
  • Also, the owner says the right muffler discoloration is due to bad needle in the right Bing carb.
  • Valve cover looks like the ones on /7. Or did the last of R90S get this too?
  • No maintenance records. Understandable if it was stored after truly running for 1k or am I getting ahead of myself? 😊
  • Front shock boot (right) is torn
  • Seat doesn’t latch/lock
What to expect?
  • Clutch rebuild
  • Lube Transmission splines
  • Brake calipers replace, bleed master cylinder
  • Lube front shocks
  • Replace exhaust because I don’t like the sound
  • Don’t know how much the panniers cost
  • New seat
  • Given the age, all the sealants, gaskets, O-rings needs to replaced sooner than later? This is my main concern
  • New piston rings?
  • I’m sure I’ve missed other important stuff
  • Importantly, how much all of this would set me back and if it is really worth pursuing?
I’m in the Bay Area, California. It’d be nice to see/meet a R90S owner.

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schrader7032
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Re: Looking to buy an Airhead R90S - first time buyer

Post by schrader7032 »

Welcome to the forum! I'm still trying to digest the bike. Hmmm...my first reaction is what is an R90S part on this bike? Certainly the engine badge says R90S, but given all that you say has changed and that we can see, I'd be hard pressed to call it an R90S. Do you have the VIN number?

I think it would be a safe bet that you might end up spending between $5K and $10K to put this bike back in good running shape and looking like an R90S. Maybe you'd spend on the lower end if you just want to fix what's there to make it reliable. I wonder if the odometer is correct, there are parts that suggest many more miles than that.

The bike is certainly what they call a bitsa or a frankenbike.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

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Slash2
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Re: Looking to buy an Airhead R90S - first time buyer

Post by Slash2 »

Run.

No seriously. Run.

You can get a completely original, albeit higher mileage R90S for $8-$12k easily. This is NOT a good candidate for a first time airhead and will be a nightmare. Mileage on a BMW is not a bad thing and if this ultra low mileage is even accurate, which is probably isn't, I'd shy away for that reason alone. A bike that has essentially sat for 50 years is going to have far more problems than one that has been ridden 50k miles and maintained properly. Find a mostly original bike, pay a bit more off the bat and be glad that you did.
Western Pennsylvanian - Airhead Extraordinaire

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r67boxer
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Re: Looking to buy an Airhead R90S - first time buyer

Post by r67boxer »

I agree whole heartedly with Kurt and Slash2, this is more likely a Frankenbike. 'Run away' would be the operative phrase. If you're intent on seriously considering it, first check the VIN numbers as suggested above. A thousand mile bike is not going to show wear like you've shown - gators, paint chips on frame, valve covers with wear marks/light road rash and discoloured headers etc.. Also, the fact that they've changed out the carbs for Bing's makes we wonder whether it was used as a donor bike for another project.

Kevin
Last edited by r67boxer on Sun Feb 12, 2023 4:49 pm, edited 1 time in total.

SDCR
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Re: Looking to buy an Airhead R90S - first time buyer

Post by SDCR »

Bayou,

Count me as another in agreement with the above assessment.

Btw, the R90S came in two distinct paint schemes, Silver Smoke or Daytona Orange. Both were two color fades.
1983 R100
2000 R1100

Tinkertimejeff
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Its Not an "S"

Post by Tinkertimejeff »

The cylinders on an R 90S have a very distinct shape along where the webbing is on the front side, those cylinders look more like R 100 units or very late R 90/6. The handle bar clamps are not R 90S. Horn is not R 90S. The gas tank is a /7 tank or a very late production '76 R 90S. Its got /7 valve covers. Its got a /7 Rear fender, Black and has the wire tie holes and straps. The center stand has had some repairs made to it that suggest very high mileage or some abuse and worn out mounting bolts and frame tabs.

It should have a 33/11 final drive, air box with drilled holes and it should have all matching serial numbers that fall within the R 90S models.

That Corbin seat looks like the lock pin has been ripped out of it. That bike is not a 1,000 mile bike, it looks more like a "bit-sa-bike" or more commonly called a "Franken-Bike". Its got nightmare written all over it.

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srankin
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Re: Looking to buy an Airhead R90S - first time buyer

Post by srankin »

I am not even going to bother picking apart what is wrong with this bike as I could spend a long time.

RUN AWAY! This is someone's mess they think is worth a lot of money (it is a BMW and an R90S Ha!) and IS NOT, and could be full of Previous Owner's disease which you will catch and pay dearly to cure if you should bring it home.

In current condition, it is a $1500 bike and that is being overly generous. St.
Owner of a 84, R80RT and 78, R100RS

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Slash2
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Re: Looking to buy an Airhead R90S - first time buyer

Post by Slash2 »

Well we haven't heard back from the OP and I sure hope that isn't because he's busy fiddling with his new "R90S". I will be curious to hear if he decided to bring this one home or pass.
Western Pennsylvanian - Airhead Extraordinaire

Bayou
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Re: Looking to buy an Airhead R90S - first time buyer

Post by Bayou »

First off, My sincerest thanks to all of you. Apologies for not replying sooner, it turned out to be an unexpectedly hectic weekend.

Slash2, I couldn't resist, so I bought the bike ......... Not! :P No way!

Nice. Nice. Nice. It's a unanimous NO! :D

I was 75 - 80% sure that I didn't want to go through but being a newbie I wanted to hear from the experts, just in case. :lol: The best thing I've done is joining this group.

SDCR, I searched hard for a 'Red R90S' but came up empty, only saw photos of bikes in DO or Silver Smoke colors. Didn't realize that's a flashing red, :oops: I'm learning.

Kevin, Yes, it has considerable wear and lot other issues for a bike that has "only run 1k miles". VIN: 4963728 (both engine and frame have the same #; I've photos). From what I can tell, it's a R90/6 manufactured in Aug '75.

Slash2, with you 100%. I'll gladly pay more for a clean, original, well taken care of bike that I can happily ride from day 1.

schrader7032, as I walked away after looking at the bike, my first thoughts were that I'd be spending $5k at the minimum though it didn't occur to me it's a Frankenbike.

Tinkertimejeff, srankin, amazed at your detective work. Ain't I glad that I brought my questions here.

I met the owner today when I went to get the VIN #s (out of curiosity). He did show the pink slip that also had the same VIN#. He went onto say that he doesn't know if it's a R90/6 or a R90S (why would he mention that if the bike wasn't messed with?), so he has priced it lower to match what a good R90/6 is worth. He further insisted that it has only 1k miles. When I showed him how stiff the front wheel is, he responded that's how it should be :( Seriously? :roll: I bit my tongue and kept quiet. I told him that R90S came only in DO and SS colors eager for his response, but he ignored. I also showed him that the seat doesn't lock/latch, as Tinkertimejeff pointed out the ripped seat lock pin, I'm sure the owner noticed that but he brushed it away saying it's an easy fix. Plenty of red flags.

I'm done with this bike. Thanks again to all of you!

As I'm spending time learning about BMW bikes, other models have piqued my interest. I'll start a separate thread with my requirements and how I intend to use the bike, your invaluable inputs should help me in narrowing down the right models and eventually buy one.

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Slash2
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Re: Looking to buy an Airhead R90S - first time buyer

Post by Slash2 »

Well that’s a relief. I might suggest you hunt for a bike being offered by a known enthusiast with a well known history. It doesn’t sound like you’re looking for a project and most vintage bikes will eventually fall into this category. That being said, for your first foray, I’d encourage you to get one you can ride and then learn the maintenance as you go.
I’d be more focused on an R75/5 or perhaps and R90/6. Nice power. Decently affordable. Not nearly as fiddly as the R90S nor as expensive and powerful AND when the time comes to upgrade you’ll be able to recoup your investment plus a few dollars as well.
Western Pennsylvanian - Airhead Extraordinaire

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