OK, I bought a barn bike today

[crazydrummerdude]

Exhaust. It's a typical 4-stroke. Nothing fancy.

I'd do what Dennis said.. strap the centerstand forward so it won't collapse on you when you're lifting the rear, bump the transmission up into 5th, and rotate the rear wheel. (This is the same version of the procedure for valve clearance checking/adjusting. You watch the valves while you rotate the rear wheel (or the allen bolt) and wait for it to get to TDC, which you verify on the side of the flywheel "OT" in the little window on the left side of the engine.)

Maybe I dive into things, but as soon as I got the bike and changed out the fluids, I'd just hook it up to a battery charger and hit the starter button for a split second and see if it rotated anything... then proceed from there.

 

[sumran]

After you have lubed the valves and cylinders and rotated it by hand, I expect you will put in fresh oil, to get rid of any solvents you have put in the engine.

If you deny it fuel and spark (ground the plugs to kill spark) you can use the starter to rotate the engine, without building too much speed. Leaving the plugs in will save a potential mess and slow the rotation. The starter will spin the oil pump enough to circulate oil through the engine. You need to be sure you have enough lubrication in the cylinders to prevent damage.

I would fill it with cheap light oil first, circulate it well using the starter and drain that well before I tried to run the motor. Then I would refill with a decent dino oil, circulate again using the starter, then give it gas and spark and start the bike. I would change the oil and the filter within 100 miles.

You will probably need a large capacity battery to do this and take care to avoid overheating the starter motor.

I'm not sure that is the best way to go about things, but it is how I would approach it.

 

[AntonLargiader]

My perspective might be a bit skewed since I have the tools and so forth here, but halfway solutions don't help in the long run:

1) If the engine is/was actually seized, getting it to turn over is somewhat academic. The top end needs to come apart since the cylinder walls are damaged. That will probably lead to a rebore, which means new pistons. New Nikasil cylinders are a worthwhile upgrade, but much more expensive.

2) Since the heads will be off, pull the valves and inspect.

3) if the tranny had water sitting in it, it needs to come apart, period. How it shifts now is immaterial.

4) Pulling the tranny means you're going to be looking at the clutch so you will probably want to renew the rear main seal and oil pump O-ring.

5) At that point you may as well replace the oil pan gasket (if it's the old cork one that's squeezing out at the sides) and possibly upgrade the sump and pickup head to the '81-on design.

The bottom end itself is probably fine, so no need to dig deeper. With the above items addressed, you should have the basis for a strong runner that's good for 100k miles.

 

[sumran]

My perspective might be a bit skewed since I have the tools and so forth here, but halfway solutions don't help in the long run:

1) If the engine is/was actually seized, getting it to turn over is somewhat academic. The top end needs to come apart since the cylinder walls are damaged. That will probably lead to a rebore, which means new pistons. New Nikasil cylinders are a worthwhile upgrade, but much more expensive.

2) Since the heads will be off, pull the valves and inspect.

3) if the tranny had water sitting in it, it needs to come apart, period. How it shifts now is immaterial.

4) Pulling the tranny means you're going to be looking at the clutch so you will probably want to renew the rear main seal and oil pump O-ring.

5) At that point you may as well replace the oil pan gasket (if it's the old cork one that's squeezing out at the sides) and possibly upgrade the sump and pickup head to the '81-on design.

The bottom end itself is probably fine, so no need to dig deeper. With the above items addressed, you should have the basis for a strong runner that's good for 100k miles.

Thanks for posting. Always glad to see your input. Would you take the same approach if the motor was not seized? The OP did not know if it was frozen or not. If it was stuck, but broke loose without much trouble, would there be a high risk additional damage by running the bike for a while, as opposed to reboring and replacing pistons immediately? If, after pulling the heads, the cylinder walls looked clean, would it be reasonable to reseal the top end and get some more miles out of the top end before rebuilding?

 

[crazydrummerdude]

Anton's got the skills and experience, but I will throw my young, dumb, devils-advocate advice into the ring; re-boring isn't always necessary.

We've got tractors, old engines, and my R90, that were seized for decades but were cleaned up and run fine now without reboring or new pistons. In some cases, we were able to even save the old rings and re-use them.

 

[rbleau]

Good Advice All

Howdy - some great inputs. I need a good definition of "stuck" or "seized". I did not try to rotate the crank until 3 days worth of Kroil and then it moved without that much difficulty, 3 or four push tries, and in 2nd gear no less.

I've also been distracted by the right caliper on my '77 R100S - different bike. Maybe a new thread ?

OK - I've spent 2 days thinking about this RS, and I believe I have figured out, with help from others, a method to prelube some bearings.

Attached is a foto of a grease gun tip I bought from PepBoys. P/N 548769. It is perfect for the swingarm bearings, I use Bel Ray Grease, but it also occurs to me that I could pull the oil pressure switch, load oil into my grease gun, use the tip, and fire some lube right up to the mains and the cam bearings, based upon looking at the oil galley flows in a BMW pub courtest of Orbitangel.

Thoughts on the lube plan ?

I could do the starter switch thing, but I want to first exhaust other methods for pre-oil.

Thank you in advance / RB

 

[rbleau]

Thanks for tips

My perspective might be a bit skewed since I have the tools and so forth here, but halfway solutions don't help in the long run:

1) If the engine is/was actually seized, getting it to turn over is somewhat academic. The top end needs to come apart since the cylinder walls are damaged. That will probably lead to a rebore, which means new pistons. New Nikasil cylinders are a worthwhile upgrade, but much more expensive.

2) Since the heads will be off, pull the valves and inspect.

3) if the tranny had water sitting in it, it needs to come apart, period. How it shifts now is immaterial.

4) Pulling the tranny means you're going to be looking at the clutch so you will probably want to renew the rear main seal and oil pump O-ring.

5) At that point you may as well replace the oil pan gasket (if it's the old cork one that's squeezing out at the sides) and possibly upgrade the sump and pickup head to the '81-on design.

The bottom end itself is probably fine, so no need to dig deeper. With the above items addressed, you should have the basis for a strong runner that's good for 100k miles.

Thanks - I do not have a fine understanding of the "seized" definition. This is my first dive into wrenching on BMWs, and is a learning experience & activity for a recent retiree from Aerospace Engineering (Skunkworks).

I fully intend to pull the tranny, and have a local shop go over it. But first I would (or should ?) like to see if I can get the motor to start.

Have already purchased an oil pan gasket - I intend to pull that, inspect it, clean pickup etc and put fresh oil in prior to hitting the starter button. Please see my prior inquiry as to methods of pre-lubing the bearings.

Thanks again - I am a novice, age 60 no less, so....please excuse ignorance. I also suffer from Engineer's Disease - I have a need to understand things in my brain housing group.

 

[mbelectric]

three words:

leak down test.

MB>

 

[rbleau]

three words:

leak down test.

MB>

Good point. Thanks. Inexpensive and produces data.

 

[mbelectric]

Good point. Thanks. Inexpensive and produces data.

And by the way, good luck on the resurrection.

My 90S I rescued from the trash pile in 1980 and still running today.

MB>

 

[mikeb921]

Short cuts

It never ceases to amaze me how some of the new generation of airhead owners are on the lookout for short cuts to put a "barn find" back in service. Anton L gave some splendid advice on what should be done but that seems to be swept by the wayside by "what kind of magical cocktail can I pour down the spark plug hole" to make this engine turn over. When an airhead engine is taken out of service, one side of the engine is probably pre combustion or post combustion with the valves closed. The other side is wide open to the elements. Depending on where the piston is (top or bottom of stroke) the cylinder walls are partially or totally exposed. This is the side that will have a bountiful harvest of rust. Rust, being one of natures most abrasive substances, will wreak havic in just a few revolutions. Airheads are "Engines 101". You'd be hard pressed to find a simpler engine to work on. Two pistons and 4 valves. Pull the darn top end apart. Cleaning and evaluating an airhead top end will pay big dividends in the long haul. If the bores look decent, run a "dingleberry" down it and take a measurement. Re-ring it. De-coke the combustion area. Resurface the valves and check the seats. Replace the pushrod seals and all top end gaskets. The bottom ends of these engines do well sitting because they're so well sealed from the elements. Ask questions here. You can get so many miles and years out of an airhead, you'll grow tired of it before you wear it out. There is a right way and an easy way, only the current owner can make that choice.

MB

 

[sumran]

It never ceases to amaze me how some of the new generation of airhead owners...MB

There isn't an airhead on your list of bikes. You need to add one so you can help us newbies get up to snuff. I am sure your approach is the best practice, although cost is a factor in the decision sometimes. The best long-term solution may not be possible.

I have no idea what the situation is for rbleau's bike or budget. I expect he will have a happy ending since he is proceeding with caution and reasonable expectations.

 

[rbleau]

It never ceases to amaze me how some of the new generation of airhead owners are on the lookout for short cuts to put a "barn find" back in service. Anton L gave some splendid advice on what should be done but that seems to be swept by the wayside by "what kind of magical cocktail can I pour down the spark plug hole" to make this engine turn over. When an airhead engine is taken out of service, one side of the engine is probably pre combustion or post combustion with the valves closed. The other side is wide open to the elements. Depending on where the piston is (top or bottom of stroke) the cylinder walls are partially or totally exposed. This is the side that will have a bountiful harvest of rust. Rust, being one of natures most abrasive substances, will wreak havic in just a few revolutions. Airheads are "Engines 101". You'd be hard pressed to find a simpler engine to work on. Two pistons and 4 valves. Pull the darn top end apart. Cleaning and evaluating an airhead top end will pay big dividends in the long haul. If the bores look decent, run a "dingleberry" down it and take a measurement. Re-ring it. De-coke the combustion area. Resurface the valves and check the seats. Replace the pushrod seals and all top end gaskets. The bottom ends of these engines do well sitting because they're so well sealed from the elements. Ask questions here. You can get so many miles and years out of an airhead, you'll grow tired of it before you wear it out. There is a right way and an easy way, only the current owner can make that choice.

MB

MikeB - I believe I understand your points and frustration, and I certainly respect Anton's advice and credentials.

Some methods are unquestionably better. I am trading "better" versus "good enough".

I am new to wrenching BMWs to this degree, but I did own my first one a while back, an 1960 R60 I bought from Irv Seaver himself in May 1972. And have enjoyed several over the years - 1974 R90/6, 1983 R65LS, 2000 R1100RS and then I decided I prefer the style, design, ride and servicability of the so-called "airheads".

I believe your key point is that trying to see if she will run may well do enough additional damage to not be worth the exercise, due to rust in the cylinders. Now that is a very useful input. Got a borescope I can borrow ?

I've already been told by friends I was a fool to get this R100RS, however I bought it as a learning tool, and I have hope that I can also get her on the road some day.

The range of suggestions on this forum is great and pretty much covers from one end to the other - from kick the tires and light the fires on the one hand, to complete teardown on the other.


Any thoughts about my pre-oil ideas for going in through the oil pressure port ?

Thanks. / RB

 

[robsryder]

...I bought it as a learning tool, and I have hope that I can also get her on the road some day....
..
Any thoughts about my pre-oil ideas for going in through the oil pressure port ?

I would not fool with the pre-oil through the oil pressure port.

If you are going to learn, then why not dive in? Firstly, take a lot of photos. Go ahead and remove the exhaust system and bodywork. Put the bodywork somewhere out of the way. If it is going to be repaired / painted, may as well get that part of the project underway. (When I got my bodywork painted I asked for the price range, including repairs and pinstriping. The painter said $1000 to $1500. I asked for the higher price range on the condition that he take his time and do a careful job. The painter just looked at me a while and said that he wished he had more customers like that. Most folks are in a rush to get stuff done. After he'd finished the painting, I paid him and requested that he store to parts for a while longer. Six months later I went and picked up the body parts when I was ready to re-assemble).

Then proceed with the dismantlement. Pull the transmission. (I'd send it to someone experienced rather than local, unless "local" is experienced.)

Pull the heads, cylinders, and piston. Remove the clutch. Block the crank and remove the flywheel.

You may need to replace cylinders - start thinking about nikisil or looking for good used pre-nikisil ones. Now is a good time to consider valve seats that can handle unleaded gas. Same comment regarding sending to someone experienced in the work over local.

You will be spending a good deal of money on parts. You can save a lot if you order from someplace like Chicago BMW that discounts. You'll need to do a lot of work getting the correct part numbers and ordering on-line (I'd follow up with a phone call afterwards to ensure getting the discount). You might be saving hundreds of dollars, but you'll also need to be prepared to wait a month or more for the parts.

You might want to join the Airheads club (airheads.org) and sign up for the airlist. There is a lot of good technical advice (sometimes) on the airlist. Use the delete key to adjust the signal-to-noise ratio.
http://airheads.org/
http://micapeak.com/mailman/listinfo/Airheads/

As I mentioned, it took me a couple of years to go all over my bike. I did much of the work myself. If you want to learn, there are some videos from CycleWorks that are instructive (even if you are not going to do the work).
http://www.cycleworks.net/videos.htm

I bought a soda blaster (and soda media) to aid in the cleaning process. Sand blasting can result in engine damage down the road.
http://www.ace-sandblasting.com/soda-blasting.html

Take lots of pictures. Don't worry about screwing up (too much). Post often. (The pictures will be invaluable during re-assembly). Holler if you need help. (I've got some photos that are annotated as to the routing of the cables around the handlebars - this took a while to figure out.)

 

[rbleau]

Got it - light bulb on

My thanks to robsmoto, mikeb921, anton, sumran & crazydrummer ...all good tips.


In 1975, I found a stored 1961 R27 for which I basically just kicked the tires and lit the fires, and I greatly enjoyed that bike.
That was when I was in Ca and the personalized plates just came out, so I snagged a plate that said BMWR27 - six letters. Hope that bike is still around; may still have that lic plate on it.

Cheers / RB

 

[mikeb921]

There isn't an airhead on your list of bikes. You need to add one so you can help us newbies get up to snuff. I am sure your approach is the best practice, although cost is a factor in the decision sometimes. The best long-term solution may not be possible.

I don't have an airhead at the moment but I've owned 3 in the past. R69S, R90S, and a R100RT. I read about you guys airhead projects here daily in total jealousy. I know I'll have another one someday. I also know there are budget concerns and skill level concerns. All I'm really saying is, while you own your bike, you are the custodian of a wonderfully engineered piece of German craftsmanship and it deserves the best you can give it. If money is the problem, stretch it out over a longer period of time. If skills are the problem, all you have to do is ask. Most airhead Guru's are more than happy to share their knowledge and many would be glad to lend a hand or a tool. If anyone lives in the Orlando area, I would be happy to help out. I surely don't know everything, but I do know these things respond very well to a good and careful owner. I logged 165k miles on my R69S over a period of 13 years. It had 35k miles when I got it, so it had about 200k miles when I traded it. Airheads are great engines to learn how to wrench on. Good luck to all and happy wrenching.

MB

 

[88bmwjeff]

Some methods are unquestionably better. I am trading "better" versus "good enough".

Thanks. / RB

RB, there's been a lot of discussion what you should and should not before firing up the engine. While I'm not a novice, I'm not an expert either. If it were my bike, I would pull the heads and cylinders off and take a look first (you did find a small bit of rust already on the rocker arms). If everything looked good, I'd just put it back together with new gaskets. It's really not that difficult to remove and replace the cylinders and heads. The first time around will take you longer, but even still you should be able to R/R the jugs in about 2 hrs each. You're going to want to replace those old gaskets anyway, since they're most likely going to leak especially those old rubber ones (e.g. pushrod seals). With the cylinders off, I would then pull the tappets (cam followers), and check those out as well as the cam shaft.

If everything looked good from the above, I would then R/R the oil pan, rear main seal, oil pump O ring. The seals at the front ends of the crank and cam shaft will probably need to be replaced as well. If the bottom end and cylinders looked good, then I'd probably pass on pulling the timing chain cover, but if the cylinders looked bad, then I'd want to pull the timing chain cover and take a look first.

After doing all the above (among other things), I would then be tempted to give the engine an attempt at starting.

This is my $0.02 on doing what would be "good enough" before hitting the starter button.

 

[108625]

Rbleau,

I have a few questions, that may help you, help us, to help you (if that makes sense):

1. How much do you want to learn?

I mean, if you learn the shade tree stuff some of us suggested and it works, you will learn that and very little of the more complex complete overhaul stuff.

If you really want to learn how to take it apart and put it back together again, and dive right in, you may never learn how to do the shade tree stuff; in danger of being the guy who can overhaul, but can't diagnose.

You could gamble on the first option as a learning experience, and then proceed with the second regardless, (or have it forced upon you anyway) if you really want an education.

2. How much are you willing to commit?

If this was an unbudgeted impulse buy, you could be throwing a LOT of money and time into it. It's easy to run out of, or reach the limit of your willingness to spend any more of, one, the other, or both.
Will it be a few hundred, or several thousand $?
A few evenings and weekends, or all of them?

3. What do you want out of this bike?

It's obvious you already aren't lacking for airheads, including another RS. When the finished product is something you already have, finishing it can be somewhat anti-climactic. So is it the bike, or the experience?
If it's the bike, do you want a totally overhauled and restored airhead, or just to see an old bike brought back to life, as close to original as possible?
If it's the experience, how much of it do you want; a taste, or the whole enchilada?

Personally, I'd suggest answering question #3, then #2, before question #1.

 

[mikeb921]

MikeB - I believe I understand your points and frustration, and I certainly respect Anton's advice and credentials.




Any thoughts about my pre-oil ideas for going in through the oil pressure port ?

Thanks. / RB

I'm not sure but I think the oil would most likely go back to the oil pan (least resistance) unless you can find a way to plug that passage. I've never heard of anyone doing this but it sounds good in theory. I'd be more worried about the top end.

MB

 

[sumran]

I don't have an airhead at the moment but I've owned 3 in the past. R69S, R90S, and a R100RT. I read about you guys airhead projects here daily in total jealousy. I know I'll have another one someday. I also know there are budget concerns and skill level concerns. All I'm really saying is, while you own your bike, you are the custodian of a wonderfully engineered piece of German craftsmanship and it deserves the best you can give it. If money is the problem, stretch it out over a longer period of time. If skills are the problem, all you have to do is ask. Most airhead Guru's are more than happy to share their knowledge and many would be glad to lend a hand or a tool. If anyone lives in the Orlando area, I would be happy to help out. I surely don't know everything, but I do know these things respond very well to a good and careful owner. I logged 165k miles on my R69S over a period of 13 years. It had 35k miles when I got it, so it had about 200k miles when I traded it. Airheads are great engines to learn how to wrench on. Good luck to all and happy wrenching.

MB

I lived in Orlando most of my life and now live in Gainesville. I hope to meet you someday soon. Perhaps at a tech day when youv'e found your next airhead. You are right about the willingness of the community to help. It is my favorite part of owning an airhead.