R100 Mono Shock Airhead, Pros & Cons

jhall · Nov 15, 2020

20774 said:
You mention that Nikasil was the answer. I'm curious...how was that a magic bullet? Is the elimination of the iron cylinder as sort of a blanket around the combustion what you're getting at? I do understand that the Nikasil bikes...as well as the Siebenrock top end kit I installed on my /7...should run a bit cooler. But there were other things going on with the 1981 models besides just the change in cylinders.

In the June 1998 Owners News, there was an index of articles. I checked that index and I don't find very much about pinging. I did find this entry:

Engine detonation 7.74.11, 1.76.15, 6.79.20, 7.79.13, 11.82.14, 1.83.12.18, 2.83.8

where x.yy.zz is x=month, yy=year, and zz=page. I only go back to the 1980s and haven't had the chance to look at those articles. But detonation and pinging are not the same, so I'm not sure what to say about the pinging issues you mention. My /7 must have been small valves...but that was never an issue. My Dad had a 1981 R100RT and I don't recall him mentioning pinging issues with his bike.

Here's the index listing for dual plugging:

Dual plugs 11.80.18, 12.80.20, 3.81.18, 5.81.28, 10.85.20, 6.87.71, 4.94.55 (hotter plug on bottom), 6.94.68.69

I went to the archives, and found only 2010 and later are available. But I did find the attached, 1981 piece, written by Tom Cutter, which speaks to the ping/detonation/knock/pre-ignition (or whatever else we wanna call it) issues I described, and dual plugging as the fix. Read and enjoy, pay particular attention to pages 4-8. http://www.rubberchickenracinggarage.com/Downloads/TomCutterDualPlugIgnition.pdf

pglaves · Nov 15, 2020

jhall said:
I went to the archives, and found only 2010 and later are available. But I did find the attached, 1981 piece, written by Tom Cutter, which speaks to the ping/detonation/knock/pre-ignition (or whatever else we wanna call it) issues I described, and dual plugging as the fix. Read and enjoy, pay particular attention to pages 4-8. http://www.rubberchickenracinggarage.com/Downloads/TomCutterDualPlugIgnition.pdf

Excellent article, of course coming from Tom. Back in "the day" I had Oak Okleshen set me up with a dual plug system for Voni's R80/7. I shipped Oak the heads and he had the head work done. He then sent the Accel amplifier and other bits to install the heads with the new system. It completely transformed the behavior of the engine in that motorcycle.

That was a 1978 motorcycle. The worst year for Airheads in the stock configuration. That was year one for new emission control standards in the US. That was the year BMW eliminated the "squish band" and set the new timing specifications. Double plugging that particular bike totally fixed BMWs flaws.

As an added comment, to any old hand with an Accel Amplifier, they sometimes would develop a fault to ground. Oak said he would supply a new one at his expense. I said don't bother. I used a plexiglass mounting plate instead of the metal one, which isolated the amplifier from faulting to ground.

jhall · Nov 15, 2020

PGlaves said:
Excellent article, of course coming from Tom. Back in "the day" I had Oak Okleshen set me up with a dual plug system for Voni's R80/7. I shipped Oak the heads and he had the head work done. He then sent the Accel amplifier and other bits to install the heads with the new system. It completely transformed the behavior of the engine in that motorcycle.

That was a 1978 motorcycle. The worst year for Airheads in the stock configuration. That was year one for new emission control standards in the US. That was the year BMW eliminated the "squish band" and set the new timing specifications. Double plugging that particular bike totally fixed BMWs flaws.

As an added comment, to any old hand with an Accel Amplifier, they sometimes would develop a fault to ground. Oak said he would supply a new one at his expense. I said don't bother. I used a plexiglass mounting plate instead of the metal one, which isolated the amplifier from faulting to ground.

Interesting how it was framed as an, "octane problem". As I recall, back then 94 RON was still available in NY State, but only at SUNOCO, but 93 was available most everywhere else. Nowadays, 93 is still available in about half the states, and 91 in most others. When dual plugging for BMWs first came out, around 1980, it was touted (by Oak, in BMW ON) as, "the answer" to ping. But as I, and most others, found it alleviated it somewhat, but did not eliminate it. Tom mentioned R60s, also, and Oak had said they were most prone of all Airheads to ping.
In 1980 the CR was reduced to 8:1 as a factory effort to deal with the, "octane problem". But, as Tom mentioned, that had been common practice by individuals for the decade prior. Finally, 1981's Nikasil jugs pretty much laid ping to rest, and they went back to 9.5:1 CR, that year through 1984. But then, solve one problem and along came another, dating back to 1977 with valve recession, mainly in, "big valve" 1000cc motors, which persisted till 1984. That was often blamed on gasoline too. Still, Airheads were head and shoulders above other motorcycle companies back then in technology, in my (probably biased) opinion.

You mentioned the Accel amp, if I recall, I used Dyna coils and Accel amp, per someone's advice back then. As I said earlier, the amp drastically reduced the current load off the points, and the contacts would live forever, then only the wear block determined point life, which was about 50,000 miles. LOL

I did slightly lean my carbs, per the gurus' advice, and they ran well. Perhaps the 78 and later were particularly prone to ping, because my 78 and 79 both pinged badly, but my 76 R90/6 hardly ever did. I have always liked the 900cc motors.

pglaves · Nov 15, 2020

jhall said:
Perhaps the 78 and later were particularly prone to ping, because my 78 and 79 both pinged badly, but my 76 R90/6 hardly ever did. I have always liked the 900cc motors.

It was BMW's need to meet those new emissions standards that posed the problem. By about '81 they had it sorted.

Off topic but I owned a '78 Dodge car. It was untunable. If it started OK cold it ran rough when warmed up. If it ran OK warmed up it was a bit+# to start. I was happy when I sold it. To make it even a little manageable I had to drill out the carb screws and install real adjustable mixture screws. 1978 was a bad year for any internal combustion engine in the United States.

stevenrankin · Nov 16, 2020

81 to 84

My understanding of the compression ratio of the bikes is that in or about 81, BMW lowered the compression ratio from 9.5 to 8 something in The US bikes. The European bikes stayed at the higher rate until they tightened their EPA equivalent standards.

From Snow bum; Nikasil or Galnikal:
These mean a special coating in the cylinders, which are also no longer 'linings' (sleeves) cast into the finned barrels. The coatings, which are extremely tough, wear extremely slowly. This change mean that the cylinders could now be all-aluminum, the older iron sleeves eliminated. Cooling was improved; the new cylinders last almost forever, oil burning is reduced by not only the minimized wear but that the cylinder roundness and taper is easier to control tightly, compression stays higher over time; and every aspect of roundness, taper, etc., is improved for the long term. This change to BMW engines was not done to reduce pinging, its introduction was at a time of reduced compression as well as the better electronic ignition. With the electronic system, timing remained stable due to the removal of the wear block on the points and the point contact wear.

I won't even touch on possible reformulation of gasoline happening at that period of time. Lead was being taken out and you can bet the petroleum industries were scrambling to figure out a safe sure way to replace it. Not only did it protect the valves but it was an anti ping compound.

All in all, between the EPA, BMW and the petroleum industry, things went kaflooey. The wonderment I have is why I never had the problem with pinging and why now, with possibly worse gas, I still don't have them?

It is interesting to look now at the new engines and what they are running for compression ratios. Back in the 70's early 80's there wasn't electronic computer controlled ignition and fuel injection.

BMW was a good bike back then, funny my friends and family who owned Honda and Suzuki never had problems. My cousin used to laugh at me when my R75/7 would start to ping while on a trip and I would have to readjust the points and mess with the timing. His Suzuki had electronic ignition I don't ever remember him doing any adjustments other than change spark plugs.

I stuck with BMW, I loved the bikes for the styling at the time, the smoothness, and the shaft drive. When I bought my R80RT new, I was happy to get rid of the points. When I bought my 78 RS a few years later, I got rid of the points first thing. Both bikes run cast iron cylinders and high compression, both are jetted at the recommended settings and neither ping.

Wait, I should not tempt the fates and I better check that my gremlin bells are still attached, the problem could arise with the current messing of the EPA with gas. Then, looks like if I am still able, to ride I will have to buy an electric bike to solve the pinging problem. St.

jhall · Nov 16, 2020

STEVENRANKIN said:
BMW was a good bike back then, funny my friends and family who owned Honda and Suzuki never had problems. My cousin used to laugh at me when my R75/7 would start to ping while on a trip and I would have to readjust the points and mess with the timing. His Suzuki had electronic ignition I don't ever remember him doing any adjustments other than change spark plugs.

Thought you never experienced ping on your BMWs?

Off topic, but I see you live just west of Rochester. I lived in Syracuse, 1975-82, and that's where I bought the first Airhead in 1981, a 78 R100/7. Have you ever gone to the Dinosaur Bar-B-Que in Rochester? I still have friends in Syracuse, including folks affiliated with the Dinosaur BBQ there. But I only visit them in summer, it's way too cold there to ever live there again.

stevenrankin · Nov 16, 2020

Please read

Jhall, I acknowledge pinging in my R75/7 BUT only when the points were wearing out. NEVER when it was in proper tune. My cousin laughed because his 74 Suzuki had a superior ignition system BMW did not. He never had pinging problems nor did he ever adjust the timing or mess with the bike other than oil changes and tires. On the other hand, I used to sigh when we had to stop all the time for gas because he got 34mpg and I got 45 with a six gallon tank.

If there had been a decent fairing available for my R75 and it had dual disc front brakes and electronic ignition I would still be riding it. It was a great bike. I traded it in for a new 83 R80RT had that for a year and hit a deer and totaled it. I had the chance to ride the first mono shock R80RT at Limerock racetrack along with the new K bikes. I ended up buying a leftover 84 R80RT bike because while the 85 was quicker handling with the smaller front tire, I couldn't see the real advantage of going up a year. I ended up with a leftover 84 and love it.

At 160K miles the pistons began to slap inside the jugs and it was time for a major overhaul. The stock compression was 8.5 or 8.2. As written, I chose a different path than buying the only BMW parts at the time. The bump up from 8. to 9.5 is minor and the bike does not ping at all. So the R80 as it stands now is running well.

I purchased my 78RS as a possible third owner, knowing the first owner who was our local dealer till BMW forced him out in the early 90's. The first thing I did was install a Boyer electronic system to get rid o the damned points. Since then, I have never had a ping. To be honest, when I bought the bike, I didn't even put 500 miles on it before the points were gone. I has never pinged even when I get caught using 87 octane gas, which I don't do except in an emergency.

I live in the village of Spencerport on the west side of Rochester. Most of the people I know in the BMW community are centered around the Johnson's creek village where Dickenson's BMW used to be and were the Beemer Barn now is. John K, opened the BB after Dickenson's closed and focused on airhead bikes only. John retired and Glenn owns it now. He also focuses on airheads. I joke it is my second home.

I have been to the Dino in Rochester but prefer the original one in Syracuse. I am afraid I don't like having to pay for parking in order to have a dinner. I haven't been to the Syracuse Dino in awhile, the last time I was there with friends, the parking was free. One of my pet peeves is the Mayor of Rochester begging people to come downtown for stuff only to incur a bloody parking fee, that of course is not a topic to be discussed here, LOL.

Yeah I hear you about the cold, I ride all year round and invested in heated gear. Problem with that is not so much the weather, but the salt used to melt the ice on the road. My R80RT is apart now in my garage getting a major overhaul, new wiring harnesses, Chrome, powder coat and fairing replacement and a repaint. Only 240K miles on it, a broken fairing mount prompted a closer look at the condition and examination of the wiring showed damage which could not just be cleaned and treated.

Enjoy the warm weather, I love this area and don't think I will ever move despite the winters. Cheers, St.

jhall · Nov 16, 2020

STEVENRANKIN said:
Jhall, I acknowledge pinging in my R75/7 BUT only when the points were wearing out. NEVER when it was in proper tune. My cousin laughed because his 74 Suzuki had a superior ignition system BMW did not. He never had pinging problems nor did he ever adjust the timing or mess with the bike other than oil changes and tires. On the other hand, I used to sigh when we had to stop all the time for gas because he got 34mpg and I got 45 with a six gallon tank.

If there had been a decent fairing available for my R75 and it had dual disc front brakes and electronic ignition I would still be riding it. It was a great bike. I traded it in for a new 83 R80RT had that for a year and hit a deer and totaled it. I had the chance to ride the first mono shock R80RT at Limerock racetrack along with the new K bikes. I ended up buying a leftover 84 R80RT bike because while the 85 was quicker handling with the smaller front tire, I couldn't see the real advantage of going up a year. I ended up with a leftover 84 and love it.

At 160K miles the pistons began to slap inside the jugs and it was time for a major overhaul. The stock compression was 8.5 or 8.2. As written, I chose a different path than buying the only BMW parts at the time. The bump up from 8. to 9.5 is minor and the bike does not ping at all. So the R80 as it stands now is running well.

I purchased my 78RS as a possible third owner, knowing the first owner who was our local dealer till BMW forced him out in the early 90's. The first thing I did was install a Boyer electronic system to get rid o the damned points. Since then, I have never had a ping. To be honest, when I bought the bike, I didn't even put 500 miles on it before the points were gone. I has never pinged even when I get caught using 87 octane gas, which I don't do except in an emergency.

I live in the village of Spencerport on the west side of Rochester. Most of the people I know in the BMW community are centered around the Johnson's creek village where Dickenson's BMW used to be and were the Beemer Barn now is. John K, opened the BB after Dickenson's closed and focused on airhead bikes only. John retired and Glenn owns it now. He also focuses on airheads. I joke it is my second home.

I have been to the Dino in Rochester but prefer the original one in Syracuse. I am afraid I don't like having to pay for parking in order to have a dinner. I haven't been to the Syracuse Dino in awhile, the last time I was there with friends, the parking was free. One of my pet peeves is the Mayor of Rochester begging people to come downtown for stuff only to incur a bloody parking fee, that of course is not a topic to be discussed here, LOL.

Yeah I hear you about the cold, I ride all year round and invested in heated gear. Problem with that is not so much the weather, but the salt used to melt the ice on the road. My R80RT is apart now in my garage getting a major overhaul, new wiring harnesses, Chrome, powder coat and fairing replacement and a repaint. Only 240K miles on it, a broken fairing mount prompted a closer look at the condition and examination of the wiring showed damage which could not just be cleaned and treated.

Enjoy the warm weather, I love this area and don't think I will ever move despite the winters. Cheers, St.

Sounds like you're 'partial to 800cc Airheads, and have clocked many miles on them, including one deer strike. Deer have always my greatest concern on a MC, till recently when I added testers to the list. As for R80 longevity, I recall a guy at a BMWMOA rally somewhere on the east coast, maybe 30 years ago, who had retired his 800/7 with the odometer sitting on 33,333, but said it was the third time around, so was actually 333,333. He brought it to the rally for display. Pretty sure he used to write articles once in awhile in the BMW ON also. Sounds like the Rochester area is still rife Airhead riders and Airhead support. The 76 R90/6 I acquired around 2002, I bought from a guy near Rochester. It was metallic green, with a Hannigan fairing. Wish I'd kept it but, at the time, only wore 3/4 helmets, which were a poor match with the Hannigan. I now wear a FF helmet, which would go well with the Hannigan. Your RS sounds nice, I always liked their style, but the riding position would not have worked for me.

Since you've been to the Syracuse Dino, you were likely greeted at the door by my best old friend, Dino. He was one of the original 3 owners and, long story short, the Dinosaur BBQ is literally named after him. You've probably heard the story how the Dinosaur began with three bikers in an old bread truck, catering to biker rallies. As the old saying goes, the rest is history. Dino tells me the Dinosaur may never be the same, thanks to Covid, but they are still doing well, mostly with carry out and catering.

We older Airheads are dwindling in number, and need to stick together. Thanks for your patience.

Joe H

stevenrankin · Nov 16, 2020

800

JHall, Sorry I have been a bit of a jerk about the posts, I admit, I may have gotten a bit thin skinned about not reading what I write if I offended, please forgive me.

I do love my 800 except when it come time to pass a line of slow moving cars. Then, I really feel the urge to crank it up to the HP and torque of the 78RS. There is a big difference between 55 or so Hp and 70 or so. Not sure the torque difference between the two bikes.

To be honest, I always liked the Syracuse Dinosaur BBQ better than the Rochester one, it was just better, hard to put my finger on it Rochester parking ruled out. I have not yet been to the one in Buffalo so I can't say anything about it.

I have alway thought the RS to be the best looking bike ever built by BMW followed closely by the RT.

The RS is surprisingly comfortable for me to ride despite the very low bars. It is a handful in slow places such as parking lots and such but great on the road at speed. Of course, I ride the RS about a quarter of the miles as the RT. St.

stevenrankin · Nov 17, 2020

overall apology

To the people whom have been following this thread, I owe you an apology for my very uncalled for behavior.

I have apologize in private to JHall, as well as the moderators but, I feel obligated to make a mass apology for acting like a jerk, and making people uncomfortable.

I have no excuse for my action.

I do want to make one thing clear, love the MOA airhead forum very much. It is a great bunch of people and the moderators do a very good job keeping me in line. St.

jad01 · Nov 17, 2020

STEVENRANKIN said:
...Boyer electronic system... Since then, I have never had a ping.

I had predictable preignition on my '78 R80/7 under load during acceleration with points (including with the Dyna points "booster" and also with the Dyna III ignition system prior to that).

Mikey over at Martindale Motorcycle Works, who I buy salvage parts from, does some neat restoration work out of his shop, and has been a good source of advice for me- suggested the Boyer and recommended Rocky Point Cycle as a source, so I bought one from Bill at RPC (along with a bunch of stainless hardware). Bill was super helpful with questions I had during the install of the Boyer. Just picked up some stainless stuff from him for my current RS project as well.

The Boyer was a definite improvement and I recommend it. I didn't bother with dual plugging as a result- no need for everyday use from my experience. YMMV.
:beer

jhall · Nov 17, 2020

STEVENRANKIN said:
To the people whom have been following this thread, I owe you an apology for my very uncalled for behavior.

I have apologize in private to JHall, as well as the moderators but, I feel obligated to make a mass apology for acting like a jerk, and making people uncomfortable.

I have no excuse for my action.

I do want to make one thing clear, love the MOA airhead forum very much. It is a great bunch of people and the moderators do a very good job keeping me in line. St.

Steven,
As mentioned in private, no need for apology here, though I certainly respect and appreciate your offering one. I too, appreciate this Airhead forum and don't ever want to be part of anything that causes friction, but may have been here recently. As time marches on our numbers are dwindling, but hopefully we can all continue to enjoy fellowshipping for decades to come, thanks to forums such as this one.
Again Steven, absolutely no issue on my part, but thanks for your concern.

jhall · Nov 17, 2020

jad01 said:
I had predictable preignition on my '78 R80/7 under load during acceleration with points (including with the Dyna points "booster" and also with the Dyna III ignition system prior to that).

Mikey over at Martindale Motorcycle Works, who I buy salvage parts from, does some neat restoration work out of his shop, and has been a good source of advice for me- suggested the Boyer and recommended Rocky Point Cycle as a source, so I bought one from Bill at RPC (along with a bunch of stainless hardware). Bill was super helpful with questions I had during the install of the Boyer. Just picked up some stainless stuff from him for my current RS project as well.

The Boyer was a definite improvement and I recommend it. I didn't bother with dual plugging as a result- no need for everyday use from my experience. YMMV.

I recall hearing many good things about Boyer. Have heard it reduced/eliminated ping, better MPG, overall ran better, etc.. No idea why I never tried one back in the day, other than being poor. That's no excuse though, as I spent a lot more $ on dual plugging, wine, women, song, etc.. LOL

20774 · Nov 17, 2020

I suspect that the reason the Boyer offered some ping relief is that the advance curve could be controlled. A Dyna III still uses the stock advancer. Probably the crank-triggered ignition systems have electronic advance curves built in to help with things like that. Might even be a true benefit for dual plugging although I'm probably talking out of hat there. But the ideal thing to do on dual plugging was to keep idle timing the same but limit the full advance timing. Since in the old days that wasn't easy to do, one lowered the idle to near 0 TDC and bring the full advance down with it. But I think jhall kinda covered that.

stevenrankin · Nov 17, 2020

Look at what his new now!

It is hard to believe that when I was looking to replace points on my bike there were limited choices of Boyer or Dyna. Now, we have them as well as the Alpha system, and the high tech zoot system Brook Reams installed recently. St.

pglaves · Nov 17, 2020

Points are so 19th Century.

stevenrankin · Nov 17, 2020

19The

I told you about my cousin laughing at me having to adjust points. Well he used to also laugh at a couple of Harley guys at his plant. He would go out after work, turn the key on is Suzuki GT380 and rather than use the electric starter he would snap the kick start with his hand and hand start the bike. Now he did this in front of two Harley riders who had kick start only and they would be in the middle of kicking and jumping to get their bikes started which of course popped, backfired, kicked back then after a fashion started in their own sweet time. When he used the electric start they really got mad.

If Suzuki had made a flat opposed twin with shaft drive, a 6.5 gallon gas tank, that looked as pretty as a BMW, I don't know if I would have be writing in this forum. St.

nickrides · Nov 18, 2020

If you still have points [ like me ] you can take the cover off and start the bike when its pitch black and watch them arc and spark. Vary the revs and they do all sorts of cool things.
Fun as hell really :wave

Nick

stevenrankin · Nov 18, 2020

Fun

My sister had an Izuzu Pup four cylinder stripped cheap pick up truck many years ago. A nice little truck for what it was.

It had electronic ignition so I never had to set timing or mess with points however despite my buying high quality spark plug wires from four different companies, it had the habit of eating them just about every 15K mies. She would complain the mileage and pep was down and I would look things over and change the wires.

What put me on to the wires being bad was the first time the performance dropped. I opened the hood at dusk on a drizzly day. Wow, what a light show under the hood when the truck was running! So after the second set of wires went, I got so on a rainy night, I would check from time to time for sparks flying. If I saw them, the truck got new plug wires.

On my old chevy with points I used to get a long insulated screwdriver at night and poke around the spark plug wires and if I saw sparks it was time for new wires. I stopped doing that with my 79 Camaro, higher voltage and I didn't want to pop the new fangled electronic ignition.

Those were the days, LOL. St

R100 Mono Shock Airhead, Pros & Cons

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