Airhead Engine Durability

[bluehole]

A couple of weeks ago my son and I were talking about Airheads and he asked how long an Airhead engine can be expected to run. I know of several Oilheads with over 100,000 miles and of course there is Voni's legendary R1100RS, but I have not heard of many Airheads with big miles or what one can expect from these engiones. I suppose engine life expectancy has much to do with maintenance over the years. Just curious as to what might be the "typical" life expectancy of an Airhead engine and if there are any stories of Airheads with lots of miles.

 

[20774]

Steve Rankin posts here a lot and I think he has a '84 R100RS that has several hundred thousand kilometers on it. Floyd "Pop" Dryer was known for riding his motorcycle something like a million miles...I think his bike of choice though was a /2.

I'm sure you'll get all kinds of numbers, but as you say, with enough maintenance and desire to repair/replace when needed, there's really no limit I would think. But can't you say that about most any motorcycle, any BMW? That said, I don't see why an Airhead couldn't be run for 150,000 or 200,000 miles.

Let the "stories" begin!! I google "high mileage airhead motorcycles" and got lots of hits...check this out from ADV:

https://www.advrider.com/f/threads/high-mileage-airheads.1324938/

Then this:

https://www.motorcycleclassics.com/classic-german-motorcycles/high-mileage-classics-1981-bmw-r80-7/

 

[robsryder]

The late Fred Tausch had over 600,000 miles on his R60/5. I believe that his bike is now in a museum in the Boston area.

There is a feller', who's name escapes me, that has a R100RS with over 1,000,000 miles on it. I last spoke with him at the 40th
anniversary gathering for the 77 R100RS at Todd Trumbore's place in Harleysville, Pa.

If one rides the bikes and maintains them (and doesn't have any mishaps - e.g. deer, accidents, etc.) the airheads are capable of going many miles.

 

[my327vette]

Karl Duffner put over 350,000 miles on his 1974 R90S during his lifetime.

 

[pglaves]

The critical issue is TBO (time between overhaul). Airhead bikes will go forever with proper maintenance and repair. It is common to find folks doing a top end (valve reface and rings) at 80K to 100K. I suspect bottom end between 250K and 300K. Eventually camshafts and followers will need to be replaced and I suspect about the same time as a bottom end. The real kicker becomes how long can you get valves, valve seats, guides, rings, pistons, con-rod bearings, etc. That will determine the life of a current Airhead. Stock up now while the parts are available???

 

[skibum69]

I would argue that airheads were overbuilt in comparison with many other bikes and the weight criteria of new bikes. Both of mine are fine mechanically but they don't have those kinds of miles on them either. I'm trying to keep the maintenance up to a reasonable degree.

 

[Darryl Cainey]

When I retired my 1977 R100RS it had over 526,000 miles.

 

[pglaves]

When I retired my 1977 R100RS it had over 526,000 miles.

What was done to the engine or the transmission in those miles???

 

[Darryl Cainey]

What was done to the engine or the transmission in those miles???

The cylinder heads were done 2 times & the transmission bearings were replaced once.

I pulled off a connecting rod & looked at the bearing shells only to put it back on.

The clutch was never replaced.

 

[pglaves]

The cylinder heads were done 2 times & the transmission bearings were replaced once.

I pulled off a connecting rod & looked at the bearing shells only to put it back on.

The clutch was never replaced.

Well, that is a very good, definitive testament to the durability of these bikes. Thanks for that information.

 

[Darryl Cainey]

Terry reminded me

Well, that is a very good, definitive testament to the durability of these bikes. Thanks for that information.

Terry reminded me that from 1992 till it was retired 2013 (was bought fall of 1986) that it was two-up and pulling a Bushtec trailer.

 

[RPGR90s]

Oilheads indeed are very long lived. Current mileage on my '04 RT is 130k and the heads have never been off and doesn't have any kind of running issues.

As far as my '74 R90s, (currently at 144k) I needed a 1st over re-bore at 110k, rings, pistons, along with valve seat resurfacing. If memory serves, I replaced the timing chain around 80k and of course, the infamous shifter return spring broke many, many years ago and was updated.
The driveshaft has never been touched, and for the first time, I had to open the rear end to replace gaskets, seals. The bearings, gears, etc. still looked brand new.

I can't really imagine servicing the crankshaft, cam, lifters anytime soon. The lifters looked perfect the last time I re-sealed the cylinders.

 

[manitou_commando]

Bought my 1988 R100 RS in 2003 with 24,000 miles on the odometer.
Now it has 104,XXX miles.
I have had the top end refreshed by Ted Porter at 98,000 m
Had gearbox refreshed at 70,xxx by Matt P
Timing chain at 70,000 m
Steering head bearing update at 101,xxx m
Alternator upgrade to EME 450W at 28,000 m

Other small things on an as needed basis, such as seals and gaskets.
It's been a really great bike to own and ride. As far as I'm concerned, it requires very little maintenance.

 

[pmcmahon]

The cylinder heads were done 2 times & the transmission bearings were replaced once.

I pulled off a connecting rod & looked at the bearing shells only to put it back on.

The clutch was never replaced.

Without documentation I call BS. I put 130K on a 78RS and 200K on other Airheads. Typically an Airhead needs the heads done at 40-60K, clutch at around 100K and timing chain about then or before. Transmissions need overhaul at anywhere from 40k (post 83’, no c’clip) to 100K. Rotors (electrical) usually go before 100K. If the rider doesn’t regularly service the rear wheel splines and transmission splines, then add those. I’ve bought a used Airhead with 35K, clean as a whistle but the owner didn’t know to service the transmission splines. The bike required a new clutch and transmission overhaul.

Oilheads are far more advanced and far more dependable. Motors taken care of will easily go 250K with little engine maintenance. Airheads are simply older technology. Even for the day the ignition and charging systems were outdated. The bikes were certainly built better than its peers but there’s no magic here. These bikes will last for a long time but require regular maintenance.

Airheads are blindingly simple to work on. A top end job, removing and taking the heads to a known reliable machine shop and reinstalling with new gaskets and push rod tube rubbers is a job most anyone can do. Pulling a transmission is another easy to learn. Airheads are easy to workon, which is great because they do need regular maintenance. And that’s to be expected. Tires wear and have to be replaced. Valves, transmission gears, seals, all wear.

 

[oldcamper]

Based on personal experience, airheads with the smaller valves can run over 100k miles. Some early 80’s R100s with big valves did not make it even to 20k before a valve job was needed due to heat recession.
Early /5’s often developed cam chain rattle around 50k, but later versions had different aluminum case bosses that allowed the chain a lot more slack before making contact noise, if I am not mistaken. I replaced my /5 chain at about 40k.
Nicasil cylinder models with small valves and short gearing are probably the longest lasting airheads. Do the failing electrical rotors count?

 

[kbasa]

Early 80s airheads, especially '83 and '84 models, will typically suffer from valve recession and will get a top end around 50K, no matter what you do. I had an 83 RS and now have an 84 CS and both wound up needing it right at 45K miles.

FWIW, Ted Porter did mine last fall and has since stopped doing that kind of work.

Bottom ends seem to last a long time if you're diligent about oil changes.

And install the oil filter gaskets correctly...

 

[stevenrankin]

My 84

So with my 84 R80RT, I have rebuilt the cylinders once, heads once, two timing chains. At about 235 ,000 miles I am still on the same bearings, cam, lifters, and rockers. Still runs strong and smooth. St.

 

[beemerguru]

R80g/s

Without documentation I call BS. I put 130K on a 78RS and 200K on other Airheads. Typically an Airhead needs the heads done at 40-0K, clutch at around 100K and timing chain about then or before. Transmissions need overhaul at anywhere from 40k (post 83’, no c’clip) to 100K. Rotors (electrical) usually go before 100K. If the rider doesn’t regularly service the rear wheel splines and transmission splines, then add those. I’ve bought a used Airhead with 35K, clean as a whistle but the owner didn’t know to service the transmission splines. The bike required a new clutch and transmission overhaul.

Oilheads are far more advanced and far more dependable. Motors taken care of will easily go 250K with little engine maintenance. Airheads are simply older technology. Even for the day the ignition and charging systems were outdated. The bikes were certainly built better than its peers but there’s no magic here. These bikes will last for a long time but require regular maintenance.

Airheads are blindingly simple to work on. A top end job, removing and taking the heads to a known reliable machine shop and reinstalling with new gaskets and push rod tube rubbers is a job most anyone can do. Pulling a transmission is another easy to learn. Airheads are easy to workon, which is great because they do need regular maintenance. And that’s to be expected. Tires wear and have to be replaced. Valves, transmission gears, seals, all wear.

Well, then how about an '81 R80G/S with documented over 200K? Big valve, dual plugged, digital ignition, etc. Top-end refresh every 60-80K as preventive since it goes to Baja and cross country, Death Valley, etc. Tranny rebuilt at 70K with a tall 5th. Fun ride...have a few customers with high miles that just keep going,, proper maintenance, and any possible issues are taken care of immediately.

And as far as the rest of your post...you need to come to the shop to see the bikes with blown engines/trannys, and fried main harnesses because they're "easy" to work on. With the correct tools and training, sure, most owners can handle SOME of the work. But a majority should just write a check. Airhead tech days do a lot of triage...some learn,...some don't

 

[skibum69]

My R65 LS shows 60659, I'm pretty certain this is the 2nd or 3rd time around.

 

[stevenrankin]

500,000

The dealer I purchased my R80RT from back in 84, had at the time 400,000 miles on his 74 R90S. When he wrecked it, it was over 500,000.

My best friend is riding a 79 R100RT that has over 200,000 miles.

Yeah so cylinders have been redone or heads, I agree they are old tech. Some of the new tech ideas in my mind didn't work out as planned. I for one am not a fan of the early nikasail cylinders as mine didn't last even a 100,000 miles before I had to rebuild. That is a long story and no, I didn't rebuild with nikasail jugs.

I did have valve recession at hight miles and rebuilt the heads.

As for the charging system, I have had to replace the brushes a couple of times before I installed a higher amp charging system. I don't have my log book on hand so I can't say when that happened but the charging system went a long way before the change without only brush changes.

Foolishly I changed the ignition system for an Alpha system because I was having cut out problems. After changing the system and two years of farting around, the cut out problem was solved and turned out to be a possible bad ground. Nothing to do with the ignition system at all. I believed the ads suggesting better performance with the Alpha system over the stock and hey, I was riding a bike that would quit running at any time so, presto an Alpha system was installed. To my dismay, there was no improvement in performance, and it didn't solve the problem. Again, this whole incident is a long long story catch me sometime and I will bore you with it.

High miles on airheads has been touted for years as they have been ridden for years. What I would like to see is if in 30 or 40 or 50 years, the current crop of wonder bikes has made the same claim to high mileage. LOL, oops, I won't be around. St.