Interesting experience at a repair shop

[paulepeterson2000]

I had recently retired, and was getting ready to take some longer rides on my 1983 R80 RT, now that I had moved back to an area with better weather. Decided to ride it to a local shop about 15 minutes away specializing in BMW motorcycles, for a safety check. The bike had always ran great, except sometimes I had to hit the starter button two or three times. I was new to the area, but an internet search did not show any bad reviews of the shop. I also told them the bike did not seem to have nearly the same power as an R100/7 I owned many years ago, and if they found something obvious, to let me know. About a month later I got the bike back, having paid about $1,900 for a new starter and new alternator. They said I would feel much more power now because the old alternator was not working. They had also done an oil change (which I did not request), and they replaced the battery (I had installed a new battery a month earlier). I ignored those two items, and was just happy the bike started on the first press of the starter, and I might experience more power, so I paid my bill and rode towards home. About five minutes into the ride began hearing an awful clanging noise. Immediately stopped the engine and pulled over. The shop picked it up, tore it down, and said the front (left barrel) connecting rod bearing had come apart. They first said it would not cost much to replace the bearing, and then said about a week later we both call around for a used bottom end. I called a shop in Ohio I had been buying used parts from for years to see if he had a used bottom end, and the foreman said the front bearing is well known to burn up quickly if the oil filter is not replaced correctly. I told this to my local shop here. A day later they sent me an email to pick up the bike and the parts, as they will not work anymore on it.

Anyone have similar experience, or an idea why the bearing went out?

[Lincoln]

Sorry to say it sounds like it might be a case of the $2000 O-ring. See below:

http://www.largiader.com/tech/filters/canister.html

all best, Lincoln

[schrader7032]

Sorry about your experience, but Lincoln is probably right. The oil filter setup on the BMW is not rocket science, but it does require some experience to do the job right.

I don't know of any BMW mechanics within 15 minutes of your location. About the closest I can find is Ted Porter at the Beemershop in Scott's Valley. That would be my choice for future work.

[paulepeterson2000]

Seems incredible if that is what happened. This is the third airhead I have owned, and have had this one 17 years. Also the first time I took one to a shop, having always done my own oil/filter changes, carb rebuilds, valves, rings, etc. Anybody know if it is feasible for me (retired engineer) to make the repairs? My Clymer book instructions suggest many hours and special tools.

[Twocams]

You could do it yourself. Think I paid $200 for the tools to rebuild my 69 R69S engine. Your engine should be easier than mine was.
And its funny, all of a sudden your engine is toasted. I do all my own work too, except any machine work.
Have fun take your time. Nice winter project, you can have it down by spring at 1/2 the cost.

twocams

[MikeL46]

You don't need any special tools to do the bottom end of 70's/80's Airhead. The only difficult part is pressing the main bearing into the holder and drilling the oil passage. I did my old R90 years ago.

Mike

[MikeL46]

You don't need any special tools to do the bottom end of 70's/80's Airhead. The only difficult part is pressing the main bearing into the holder and drilling the oil passage. I did my old R90 years ago.

Mike

[Twocams]

Personally I would be tempted to remove the filter cover. Measure the filter housing with filter in,to see if there was a problem.
That would give me a little piece of mind. It has to be done anyway or you could loose another engine?

twocams

[schrader7032]

Anton's site covered the issue with the /7-on filter setup. The filter sits in a canister. The issue is the distance the canister sits below the outside of the engine case. If the canister is about 3-3.5mm below the engine case, typically a thin metal shim and one large white o-ring is used. The metal shim is used to protect the o-ring from being cut by the sharp edge of the canister. The goal is to compress the o-ring around 25% of it's thickness when the cover is put back on. The o-ring provides all the sealing needed...no gasket is required.

If the canister is more than about 3.5mm, then it's necessary to add additional metal shims to make up the difference. If the canister is less than 3mm from the outside edge of the engine case, then a gasket is used under the cover. The gasket doesn't seal oil, but simply moves the cover out a bit so as not to totally crush the o-ring. My R100/7 has it's canister at 2.8mm from the outside edge. I've used one gasket and lately have been using two gaskets as the computation for compression for the o-ring show too much Too much compression could lead to splitting the o-ring which results in oil pressure and filtration problems.

Snowbum also covers the $2000 o-ring here:

http://bmwmotorcycletech.info/Oil.htm

[khittner]

What a nightmare. Your "safety inspection" turns into a new engine. If your engine suffered a bearing failure as the result of low oil pressure, there could be metal bits scattered throughout the engine, and it'll take a complete disassembly and rebuild to check and correct. The "low altitude" warnings should've gone off when the shop claimed that you should feel more power as the result of an alternator replacement; unless the "more power" was going to be some electrical current jolting through you, a new alternator wouldn't do anything for the ol' butt dyno. There are really very few shops, including roundel-equipped dealerships, that are competent to work on airheads anymore. You might also want to join the Airheads BMW Club for their list of "airhead-friendly" shops. You may find a new-to-you R80RT is the better use of funds.