I spent a couple hours last night trying to get the gas cap on the R75 open.
Today I'm considering selling a couple shares of GameStop and buying a new tank for ~$375 - The bike will be a better long term investment.
When the seller told me that the gas cap was stuck, I didn't think it would be a big deal. Spray some oil on it, let it sit overnight, then unscrew it. Nope.
Searching online, I found that it is not an uncommon problem. This web page looked promising: http://www.largiader.com/articles/gascap/ It explains that the cap is a ratcheting cap which is engaged by a pawl. The pawl spring can get stuck or the plastic housing can crack, making it so the cap can spin endlessly without unscrewing. The 'drill a hole' method looked simple and promising.
I have now drilled three holes, broken seven drill bits, five screws, and three nails. The internal plastic is broken down into tiny pieces which I extracted with needle nose pliers. The lock and pawl are destroyed. I chipped the paint on top of the tank. The gas cap is still secure. I'm planning to give it another try tonight. If I fail tonight, the next step will be with tools that turn metal into dust. Due to a fear of heat and sparks in the vicinity of fuel vapors, I will plan to remove, drain, and purge fumes from the tank before taking that step. My EMS worker memory has flash-backs of a guy who was welding while sitting on a not-quite-empty gas can. Bad idea.
Dang, sorry to see that you're running into an issue with the stuck cap.
R75/7: The gas cap is open and destroyed. I ordered a new one a couple days ago when I first read about the 'drill a hole method' and it should be here by Monday. To remove the cap, I used three holes with 'Tapcon' screws. They were strong enough to hold and not bend or break. The interior of the tank doesn't look great, but for now it will be fine. I drained the rest of the fuel checked the bowls on the carbs and replaced the upper fuel hoses.
Next will be figuring out why the center stand doesn't stay up even though the springs look good. Why does it have *two* side stands? Pick one and remove the other. The big luggage box behind the seat is removed and I'm undecided about the future of the big clear fairing. Insurance and registration is planned for Wednesday.
R60/5: A new gasket & O-ring kit for the carbs has arrived, but I'm still waiting for the 'parts carb' to get here. I have new spark plug wires from Euro Motoelectrics and I may install them tonight. One of the old ones is cracked and was giving me a nasty shock if I touched it with the bike running.
XT225: I hosed it off after having a great day at the Big Meat Run and now it sits ready for whatever is next. Most of the crowd at BMR was driving modified Jeeps or side by sides, but there were other bikes there. I did pretty well on the trails and transiting areas of the riverbed with bowling ball sized rocks in my path. I just had one big oops when I was off by myself and tried to climb up a very steep, loose trail. About half way up I realized that I would die if a 4-wheeler crested the top and came down. I slowed a little and looked for 'outs'. Three quarters of the way up I stalled out and laid it across the slope. There was no way to ascend further with zero momentum at that point. I slid back to the bottom, brakes locked up and rocks, dirt, and leaves coming down with me. No damage or pain, just the thought that if I had gone 'full send' I would have made it to the top. A friend has invited me to the Arkansas 500. It looks like an awesome Dual Sport event, but we are short handed at work and I don't think that I can take those days off. Maybe see if I can hit it for a half day or two.
That point where you have multiple project bikes going at once and all of them are waiting on parts so you just walk to the garage and look at things. Good stuff.
Looking like your having a grand ol time.
FMB42
Reader
3/26/21 1:07 p.m.
I often just sit and look at various projects in my garage regardless of what parts I have on hand or not.
There was a local fatality yesterday. A car pulled onto the highway right in front of a motorcycle that was estimated at 65 mph. The paramedics did what they could, but 'called it' on scene. A reminder that bikes are invisible to other drivers. I think that there's a lot that I can learn to keep safe, but sometimes there may nothing you can do.
After work, I put fresh gas in the R75 and drove it around the neighborhood for 15-20 minutes. When the engine is warm it has been smoking badly on the left side and I wanted to see if I could burn it all out. I figure that it was on the side-stand for a long time, leaning left, and oil seeped past the rings for a while. By the end of the ride, it was mostly cleared up. I'm really looking forward to getting it out on the road once I get it registered.
My k75 would smoke like crazy if left on the side stand. They were pretty known for it.
Yeah, the smoke isn't untypical even on later bikes including the oilheads. Especially if you parked it on the sidestand with a hot engine and hot oil.
Regarding the sidestands - is one of them bolted to a lug on the frame and the other one just clamped on the frame? Aftermarket sidestands are a thing for these as the OEM one isn't that great at holding up the bike. If one of the two is clearly aftermarket, I'd try to find out what it is - some of them are pretty sought after, others not so much.
One other thing I forgot to mention - I think these have the front brake master cylinder under the tank with an actuator cable from the handlebar grip. If that's the case, this is a) a mechanism only a German engineer could love and b) the master cylinders are notorious for leaking and will do so for a while before it's noticeable. If you don't have a bike with the master cylinder on the handlebar like the later ones, definitely pull the tank and check the master cylinder. I'd probably consider converting to the later master cylinder, but that might just be me.
BoxheadTim (Forum Supporter) said:
...Regarding the sidestands - is one of them bolted to a lug on the frame and the other one just clamped on the frame? Aftermarket sidestands are a thing for these as the OEM one isn't that great at holding up the bike. If one of the two is clearly aftermarket, I'd try to find out what it is - some of them are pretty sought after, others not so much.
Thanks, I'll get a picture posted and see if I can figure out which it is. It seems to work a lot better than the stock one. The center stand spring is weak and gets slightly jammed between the frame and the engine. I think it may be routed wrong and needs repositioning.
One other thing I forgot to mention - I think these have the front brake master cylinder under the tank with an actuator cable from the handlebar grip. ...
Yes, cable from the grip to master cylinder. I noticed last night that the brake light stayed on until I bumped the handlebar grip a couple times. The brake works well, but I will take the tank off to check for leaks and flush the old fluid out. I ordered the Clymer manual to have some organized paper instructions (about 800 pages covering 1970 - 1996) rather than relying on the web for everything. It should arrive Tuesday.
Not sure if this helps, but this is how the spring is mounted on my '81 R100RS:
The Clymer manuals are usually my choice for these bikes and the early K bikes as well. They're pretty comprehensive, especially compared to the Haynes ones.
BMW Airhead Stands: The R75 has a spring that looks the same as Tim's R100RS, but not the same mounting or hardware. It doesn't work and has become distorted. I tried to find other ways to position it and had no luck.
I went online back to EME, found the correct spring for $3.99 ea and bought four (two for each bike), then bought some new cables for the R60/5 to get the shopping cart to about $100.
The side stand on the R75 is a "Brown". 'Snowbum's' website has lots of info on these bikes including a page dedicated to stands: https://bmwmotorcycletech.info/FarleyBrownSurefoot.htm I like the Brown stand a lot better than the stock one and will probably remove the stock one when I run out of 'important' things to do.
Brown Surefoot is definitely like winning the sidestand lottery. I'd definitely remove the OEM side stand for one of those!
BTW, looking under my R100 was bad for my wallet 
. Looks like the lower fairing has sustained more damage than I thought it had, either on the last move or in the container over from the UK. Fortunately those things are reasonably easy to find in decent shape and your thread kinda inspired me to get that bike at least into a shape to ride it locally a bit.
I'm not very concerned about cosmetics yet, but it's a slow morning at work, lots of pictures on the internet, and a few $ left in the bank. The R75 came with two fairings. One is a big clear acrylic one that is currently mounted on it. The other is the stock fairing, painted in the original brown color of the bike. I don't have a pic of the stock one, but it's like this:
I don't have any objection to that. I think that will be fine for Mrs AAZCD, but my taste is more like this (below).
I think I will style the R75 (hers) similar to this:
and the R60 (mine) similar to this: BMW 60/5 Cafe Racer
I love these, but having the bikes look like that ...would make me want to ride like that.
The fairing in the top photo looks like Vetter fairing to me - the regular "/something' models didn't come with screens or fairings from the factory, for that you needed one of the 'letter' models like the R90S, R100S, R100CS, R100RS or R80RT/R100RT (and a specific model of the R100GS). Retrofitting the 'S' fairing is a pretty common mod, I would just recommend to also swap out the handlebars for 'S' handlebars so the aerodynamics actually work. I believe the fairings in the bottom picture are based on the Dunstall fairing, which was pretty popular in the UK for cafe racers. Usually the Dunstall ones have longer "lower" legs, though.
If you want to keep the upright seating position and thus the handlebars, I would stick to the Vetter or maybe just a smaller flyscreen.
Also, those Vetters are pretty heavy - they're 70s fibreglass after all - so you may want to check if someone upgraded the fork springs.
Yes to lower handlebars. This just looks wrong:
Low handlebars and leaning over the tank has always felt right to me on the street. I tried a cruiser style with the Kawasaki Vulcan I took in trade a few years back. Totally wrong feeling and I couldn't get used to it. Even with the XT225, If I'm on a long stretch of pavement, my knees press the tank and I'm leaning forward putting my face near the headlight cowl. (Probably looking pretty stupid on that bike.)
In other news, I received a message that the 'parts carb' that I bought on eBay was canceled. "Out of stock or item was damaged." Money refunded. I'm going to think it over for a while now. Clean up the old carb as well as I can, then decide if I want to replace it or go with a conversion to Mikuni carbs. I'm not against the conversion. People who have done it report that it works well. I just prefer the simple old Bing sliders if I can get them working right. If anyone reading has an old Bing type 53, or specifically a "1/26/111" good parts or whole, I'm interested if it's not too pricey.
I am so excited that you picked up the BMW, and I really appreciate everyone sharing their knowledge on the subject here. I've wanted an old airhead for a long time, but like many things on the internet it is tricky finding good info. There's a ton of solid forums but there is always a balance between what knowledge is assumed and what is explicitly shared. Getting the info here straight from experienced users (Boxhead Tim, et al) makes it much easier.
I'm trying to not buy any more for a while. That doesn't stop me from looking though. Here's two on Facebook Market that look interesting today:
https://www.facebook.com/marketplace/item/154329219883547/
https://www.facebook.com/marketplace/item/3790626881027546/
Mezzanine said:
I am so excited that you picked up the BMW, and I really appreciate everyone sharing their knowledge on the subject here. I've wanted an old airhead for a long time, but like many things on the internet it is tricky finding good info. There's a ton of solid forums but there is always a balance between what knowledge is assumed and what is explicitly shared. Getting the info here straight from experienced users (Boxhead Tim, et al) makes it much easier.
It's great to have Tim's expertise and the forum here to help out. Most of the forums that I've looked at so far take a lot of digging to find what I need and are presenting what seems to be unqualified opinions, often opposing each other. I have found a few places on the web that have good, well indexed info for these bikes:
Nice, thanks for the resouces! I am currently focused on my two Moto Guzzi and trying to avoid any more bikes right now. You're not helping. 
A few unimportant notes: I realized that I purchased the BMW motorcycles way too casually. I bought what I wanted, but I could have [*should have*] done it a lot better.
The R60/5: The deeper I dig into the bike, the more things I see that were done poorly in previous work. Some bolts are missing, others are incorrect. It has a new main wiring harness, but what has been installed on it is shoddy. There was no oil ***NO OIL*** in the rear drive. The title was open from the second previous owner back in 2018. Oklahoma charges a fine for every month that a vehicle registration is expired. Because of the three year lapse in registration I paid almost $500 to get the tag and title done.
The R75/7: It is a nice bike and was well cared for up to about two years ago, but has sat unattended since. The seller didn't try to hide anything. He was nostalgic about it, but really needed it gone. He easily knocked $400 off the asking price and gave me lots of extra stuff with the bike. Handed me the signed title, shook hands and I was on my way, driving two hours back home. A week later when I went to register it, the clerk pointed out that he had signed it on the line for "Lien Holder" rather than seller. The title transfer was no good unless I could get an affidavit from the seller stating that there was no lien/signed in error and have him sign in the correct place. I arranged for a notary and drove back to his house today to get the paperwork done. It was a whole afternoon shot, to take care of paperwork that I should have caught immediately when I was buying the bike.
Nobody to blame for any of this but myself. If I was paying attention and watching out for myself, all of the pain and surprises could have been avoided or mitigated.
The R60 needs a lot of work, but it is registered and insured since last Wednesday. So far I have it 'running in general' with a headlight. That works for around the block to warm it up and check things over. The left carb is doing much better with a simple cleaning done. I put new spark plugs in today to replace the mis-matched plugs that were in it. I put and old air filter in after discovering that there was NO filter installed. Next I plan to go over the wiring from end to end, then go through the Clymer manual section on Lubrication and Tuning following the whole chapter in sequence.
Here's how it sits right now (That seat needs to go.):
Here's a picture with a quarter fairing duct taped to the front (That's not going to get mounted until most of the issues are worked out.):
The R75 is on the road now. It is Mrs AAZCD's bike, but I'll probably ride it through the Summer before she gets her license. Nice bike and it rides well. I'm planning to give it a good cleaning and seasonal maintenance before I put miles on it.
This one will stay styled as it is, a classic comfy cruiser, while the R60/5 is more likely to be 'modified' rather than 'restored'. I'm still undecided on exactly what to do with the R60, but after seeing where the past neglect and abuse has put it, I feel more at liberty to get creative with it than I originally did.
AAZCD (Forum Supporter) said:..., while the R60/5 is more likely to be 'modified' rather than 'restored'. I'm still undecided on exactly what to do with the R60, but after seeing where the past neglect and abuse has put it, I feel more at liberty to get creative with it than I originally did.
Ok, yes. I was not going to 'restore' the R60/5. Too many minor parts, nuts, and bolts are missing or in bad shape. The cost of collecting everything needed to make it right did not make sense for an old, mistreated bike. I was considering continuing it's trend of cobbled together fixes to just keep it running and not making it 'right'.
Well, things changed. I had messaged the guy that was selling the 1972 R50 on Facebook. I was going to see if he would sell me a few parts that he could box up and mail to me. A couple days later he replied and offered to drive to Oklahoma to deliver the whole bike if I'd pay for his gas money - almost a five hour drive each way. He was available to do it yesterday, my day off, so I met him part way in Joplin and picked up the bike.
It was actually found in a barn that his family was clearing out. It appears that it was last registered in 1973. Someone started working on the engine long ago, then apparently stopped and walked away leaving the heads unbolted. The right piston is seized pretty good and the rockers, push rods, and valve covers are long gone. Almost everything else is there. It seems to have been kept inside in a fairly dry environment for 50 years and all the parts that I want for the R60 look like they are in good useable condition. The left side carburetor is there and in better shape than the one currently on the R60. The wiring in the headlight looks great and the insulation on the wires is still soft and flexible. This is an awesome parts bike for my needs.
So...... what's the future of the parts bike.......
