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rimcanyon
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I came home yesterday with a '67 R60/2, so the adventure begins. It needs a lot; it is basically a barn find with a seized piston, with a few parts missing.

The missing parts are an Earles front end, a speedometer and a 6V coil. Everything else seems to be there.

The left piston is seized due to rust. The head is also frozen in place. I plan to drill out a spark plug and insert a grease nipple and see if I can get the piston moving and the head off with a good grease gun.

-Dave

schrader7032
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VBMWMO #7032
San Antonio, TX
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Time is really your friend

Time is really your friend here...obviously you'll have some serious work to do when/if you get it free. But use penetrant and let it sit for days. The best penetrant is a 50-50 mix of acetone and automatic transmission fluid. In a drastic situation, if you can't get the cylinder off and there's enough room to rotate the cylinder to expose the rod, you could cut the rod. That's pretty serious, but at some point you have to move on to get at the rest of things.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

caker
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Philadelphia area (NJ)
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For magneto ignitions the

For magneto ignitions the voltage of the electrics (and battery) on the bike have nothing to do with the ignition system. So, by my understanding there is no such thing as a "6V coil" on a magneto bike's ignition ... it's simply an ignition coil... but, we know what you meant Smile. I just keep seeing the same thing said in other posts and couldn't resist throwing this out there...

I would think the head should come off without anything drastic like drilling holes and pumping with grease. Just make sure you've got all of the bolts out, and try to gently work it off.

-Chris

rimcanyon
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head is off

caker wrote:

For magneto ignitions the voltage of the electrics (and battery) on the bike have nothing to do with the ignition system. So, by my understanding there is no such thing as a "6V coil" on a magneto bike's ignition ... it's simply an ignition coil... but, we know what you meant Smile. I just keep seeing the same thing said in other posts and couldn't resist throwing this out there...

I would think the head should come off without anything drastic like drilling holes and pumping with grease. Just make sure you've got all of the bolts out, and try to gently work it off.

-Chris

Chris, thanks for the education on magnetos. Makes sense. I have a lot to learn. I have been working on 60's Porsches and VW's for years, so I'm sure some of the things I think apply don't.

You were right about the head. I was going by what the seller told me, and it turns out it was incorrect. The head is off, and the hardest part was getting the exhaust ring off. I tried a pin spanner that fit fine, with a hammer, then with a bigger hammer, with lots of penetrant, and added some heat from a mapp gas torch. No go. Finally resorted to a tapered punch and that got it moving. The good news is that the cylinder wall is not scratched or rusty - it looks like it has minimum wear. But the engine is still locked, so I'll investigate more tomorrow. The other head and cylinder are already loose - it came that way from the seller.

When I took off the left valve cover I found a high water mark and rust. Kind of weird. I think water was leaking into the valve cover while the bike sat for years. I haven't disassembled the head to see if the valves are frozen in the guides.
-Dave

schrader7032
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VBMWMO #7032
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Not sure I see the fine

Not sure I see the fine point...it's a coil and it operates using 6v. Seems to me it's a 6v coil. It's not a Kettering system which has rising/falling saturation in the windings...dual windings. The magneto coil is one big wire loop (I think) and the permanent magnet is used to switch the poles (I'm stretching here). But the end result is the same...a flood of current to the spark plug. Still seems like a 6v coil to me. Thinking

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Darryl.Richman
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Surf City, USA (Santa Cruz, CA)
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Kurt, the magneto coil

Kurt, the magneto coil doesn't operate at fixed voltage like a Kettering system coil does, so there's no spec. In a magneto, which does have primary and secondary windings, you get whatever voltage in the primary can be induced by the moving magnet, which varies as the magnet rotates from pole to pole. The system designer knows what this is, but nobody else cares. The magnet and coil are parts of an integrated system.

A Kettering coil depends on having the right, constant, DC voltage provided by the battery/generator, so it's important to know if it's a 6V or 12V coil.

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legac
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Dave: Your bike sounds like

Dave:
Your bike sounds like it had a water intrusion issue so this may not apply but when I got mine many years ago the motor seemed "frozen". I pulled the heads and they were free.
It turned out that just before the old owner died he had a new clutch installed. He did not ride the bike because he got ill and it was not "right" as he told me.
Seems that the mechanic used some of the wrong components and it caused the clutch assembly to be pressed up against the face of the transmission so it was impossible to kick start the motor.
Took a while to figure that one out!

rimcanyon
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The final drive is

The final drive is disconnected on mine, so even though the clutch is engaged it should still be possible to turn the motor over, even if it is in gear.

When I look at the state of the bike, I see evidence that someone started to repair it but never finished, then it was owned by one or more others who partially disassembled it. The magneto and generator are in a box with greasy nuts & fasteners. The engine is clean. Some studs and nuts are new. The right side cylinder is loose (nuts are finger tight). The wiring and cables are old and disintegrating. The interior of the engine is clean but the left valve cover had water intrusion so at least an inch of water was in it, at an angle (it looks like it was on the side stand, which is fortunate).

The plan is to remove both cylinders, get it rotating, check out the pistons, rings & crankshaft, disassemble & check the heads, clean it carefully, and if no problems are encountered that lead to further disassembly, re-install the cylinders and heads, rebuild the carbs, connect the magneto and generator and get it running. Then tackle other issues.

-Dave

rimcanyon
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The stuck piston turned out

The stuck piston turned out to be on the right side. I converted an old spark plug into a grease nozzle, and used grease to push everything apart. It worked really well. The cylinder walls above the rings have a heavy coating of rust, and below the rings it was nice, you can still see the cross-hatching. I will try honing the barrel, but it is probably going to get rebored. Where can I get the dimensions for maximum piston/cylinder clearance and piston/cylinder oversizes?

Is it acceptable to run the engine with one 72mm piston and one 72.5mm piston? That is only a 0.7% increase in swept volume, so the difference in power is not going to be an issue. The weight difference is more of a concern. What is the max. difference in weight between pistons?

The crank rotates fine now, and the insides look really clean, so the plan is still to do a top end rebuild only. I think this is a really low mileage engine after seeing the left cylinder and the portion of the right cylinder below the rust.

schrader7032
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I don't know these dimensions

I don't know these dimensions off-hand. I'm sure the Barrington Manual provides it. There is also a service manual that was sold for the /2 machines...it is not very expensive...I think I bought one for $25 when I first got my R69S. Right off hand, I'm not sure where to pick one up. Likely Vech sells them.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

rimcanyon
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Barrington and workshop manuals are on order

schrader7032 wrote:

I don't know these dimensions off-hand. I'm sure the Barrington Manual provides it. There is also a service manual that was sold for the /2 machines...it is not very expensive...I think I bought one for $25 when I first got my R69S. Right off hand, I'm not sure where to pick one up. Likely Vech sells them.

I have both on order. Probably have them in hand by next week, but in the mean time, if anyone can look it up I would appreciate it.

malmac
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page 25 of the workshop manual

I had a look in the BMW repair manual - no figures for permissible weight difference of pistons is mentioned. Neither in the specs page 25 or the text of the manual. The Clymer manual also does not mention the matter.

Barrington on pages 209/210 speaks of balancing the pistons but does not give a spec. I quote ..."to bring the two assemblies as close as possible to equality."

So not much help - sorry.

Mal

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rimcanyon
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I'm surprised it isn't in the

I'm surprised it isn't in the manual. I just checked the Porsche 356 manual, and the figures of interest are .20mm (.008") for maximum piston clearance for cast iron cylinders and 10 g for maximum piston weight differential. The engines are similar enough that I can probably use those numbers.

Another question I have is whether the rings being sold today will fit the 1967 R60/2 pistons. I received an email from Uwe Meyer that seems to say they won't work. He said: "Genuine pistons manufacturer are Mahle, Kolbenschmiddt, NĂ¼ral. All used different tools and rings by manufacturing.

The only one company for production from genuine pistons now is Kolbenschmidt. The pistons and rings are new productions match not in any cases the old ones."

However, he doesn't say they won't work, only that the design changed, at least I think that is what is meant. So if the ring widths match the 67 piston, then it should work. Unfortunately the ring sets listed on various websites don't give the sizes of the rings (except the diameter).

malmac
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Toowoomba, Australia
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Here is the full page of specs

1446 pxx2048px

This is the only page relating to piston specs in the factory manual.

I hope the other numbers are helpful.

Mal

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mal - R69s
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rimcanyon
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Mal, thanks for posting.

Mal, thanks for posting. That gives me the info I needed. I am going to use two new KS pistons so the weight difference is no longer an issue.

-Dave

808Airhead
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Dude,if you are going to take

Dude,if you are going to take it apart do it all,imagine all that work only to run the engine and destroy the crankshaft. These engine really need/deserve care when rebuilding and I would never dream of running different pistons and running a motor that had any corrosion in it,unless you are just fixing it for a quick flip. If you are intending long term ownership,do yourself a favor and strip it down all the way. Then you will only "cry once" and do it right.I recently rebuilt my R60/2 engine and here is a estimated breakdown
1.rebuilt crank cost $750.00 (1/2 cost of brand new)
2. Kolbenshmidt pistons,$475.00
3. Bearings,NOS FAG/SKF main bearings,made in Britain and Canada,not new production Asian bearing,nose bearing,Japanese Nachi from cycle works $130.00
4. Gaskets and Viton seals,$120.00
5. Powdercoat cylinders,$80.00
6. Bore cylinders,$130.00
7. Stainless pushrod tubes,$90.00
8. New rotating style valves/retainer/keepers $250.00
9. Grind valve seats/blast heads/rebuild heads $280.00
10.Soda blast case,$25.00 materials
11.Stainless steel headers and mufflers $1200.00
12.Stainless cylinder base nuts,$30.00
I reused my slingers which were fine and my rear main carrier was still good,but if yours are not,then add $220.00 for those..
I did all the labor myself other than the boring and valve cutting/head rebuild. My engine runs better than new and this is what it cost me for a REAL rebuild. Good luck.

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Thomas M.
R69s - R60/2 - R67/2 - R51/3

malmac
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Toowoomba, Australia
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Dave - enjoy the journey

Dave

My son and I have been rebuilding his engine for several months - just other commitments have made it drag out - but none the less we have spent a lot of hours on it and it has cost a fair few dollars.

We are learning heaps and going slow so we don't inadvertently stuff something up in the long run.

So I hope you enjoy getting to know your bike and you are able to enjoy the rebuild process.

Mal

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mal - R69s
Toowoomba- Australia

rimcanyon
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Joined: 04/11/2015
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I'm learning things the hard

I'm learning things the hard way, i.e. from the ground up. I just figured out that the front wheel on the bike is not original, and it came from an earlier machine. It has duplex front brakes. At least I figured it out before I put money into the wrong parts (it needs a brake cable and the swivels). They are full width, so I assume the braking will be equivalent, and should work until I find the right part.

@808Airhead: I can see you and I have a different outlook, to each their own. My view is that getting the bike running first means that you will have a working bike and can do things incrementally. I've seen too many projects (including some of mine) turn into decades long projects without a working machine.

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