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ringerbeem
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I have inherited a 1952 r25/2, mostly together but missing odds and ends. My biggest issue is that i have a badly bent crankshaft and a bent frame( at the front tree mount which looks to have at one time hit head on with something. First with the frame, is straightening it an option? or can i find a donor frame? also with the engine, i am considering finding a donor as well if machining will cost more than its worth. I am not too concerned keeping it matching numbers. This bike has been sitting around for 40 years from my grandfather to my dad now to me; this bike needs to be built. I am reasonably skilled with auto mechanics but bikes are totally new to me.

I am in toronto and i have been in contact with bench mark works Canada but i am trying to save some money and source out what i can myself.

And how special do i need to be to access the classifieds?? Smile

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'52 R25/2

schrader7032
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1952 R25/2 project, totally new at this

How about that! I just added a '52 R25/2 to my fleet. Mine was built in June 1952. It served some of its life as a police bike in Germany.

For me, keeping the numbers together is important so I would do what it took to keep it that way. Obviously, it might cost. But that's me.

Frame - finding an R25 is one thing...finding a frame would seem even more difficult, unless you could find another severe basket case. I've heard about "The Frame Man" I believe in California. You might try a search of the forum for frame straightening. Possibly some discussions with them could help determine if it's possible to get it straightened.

A question I might ask, is just how important will a perfectly true frame be for an underpowered, less than 70 mph R25/2? I'm betting that it could be straightened enough to make it safe enough.

Engine - again, maybe you can find a donor. You might consider joining the Yahoo Mono club to expand you reach. One of the posters there, Richard, is quite experienced with the singles. He might have a crank. Also, you could check with Dan at Cycleworks. They work with crankshafts, or maybe they did. But they were the only source that I knew of for this kind of thing.

http://autos.groups.yahoo.com/group/bmw-mono-club/
http://www.cycleworks.net/

Cycleworks can also be a good source for tools and other resources to perform work yourself.

For the forum's classifieds, I think you'll heard from the moderator, but you'll need to become a member of the VBMWMO to get to those services. You could try a wanted-to-buy post in IBMWR.ORG's marketplace.

Good luck...I hope you can get it on the road.

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

schrader7032
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1952 R25/2 project, totally new at this

Just ran across this...Uli's in Germany apparently sells new crankshafts:

http://www.ulismotorradladen.de/englisch/rechts.htm

Kurt in S.A.

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

Peter
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1952 R25/2 project, totally new at this

Yes Ulis and Stemler in Germany sell cranks and cylinders new; for most vintage BMW's

I think Stemler even sell the frame however it would cost a lot, you can access their website download the catalog and price list for free.

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R42, R12, R51/3, R69S

ringerbeem
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1952 R25/2 project, totally new at this

thanks for the replies! I have a lot to tackle. And maybe i should learn some german for that uli site.

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'52 R25/2

808Airhead
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1952 R25/2 project, totally new at this

Dude,just click the "English/British" flag.........lol It converts it to English.......you owe me a beer now. Cool Laughing

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

ringerbeem
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r25/2 finally running, almost...

So after 3 years, I finally have this baby running. Well, it was running. Yesterday is started fine, today, no start. I pulled the plug which was wet, so i dried it off and grounded the plug while in the wire and kicked it over, realizing that there is a weak spark. The batter seems low now because lights and horn are very weak. Any suggestions? Does a weak battery affect the spark?

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'52 R25/2

schrader7032
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Yes, the R25/2 is a

Yes, the R25/2 is a battery-coil ignition. No battery, no start...weak battery, weak spark. You probably just flooded the carbs which is understandable as you learn what the bike wants in order to start it. Don't tickle quite so much...if it doesn't seem like it wants to catch, tickle a little more. Be sure your timing is set right as well as the valves.

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

ringerbeem
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R25/2 help for a newbie

thanks for the confirmation on the battery, im charging it and i will see what happens. Timing and valves should be fine as it was running when i picked it up from my mechanic who is a vintage bike specialist.

On other topics with my bike, the cylinder head bolts seem to keep losing their torque. Apparently this is due to my head's poor aluminum. We re-torqued them 3 times, now i notice that the bike is burning oil and smoking out the tail pipe at high rpms. COmpression is low but enough to run ok. Could the cylinder head gasket have been compromised after torquing so any times?

I have ordered a rebuilt head from germany as a spare so i will try that one out to see if the alloy is any different

Also, I didnt change the cylinder or the piston because they seemed fine, just changed the rings. Im ordering a new piston and will bore it over soon. The original cylinder being left and honed out could be a culprit for burning oil excessively too so thats why i will bore it out anyways.

Generator:
How do i test the generator to see if its charging at the correct rate? can i use a voltmeter? what is the rate of charge?

Wheels:
Mine seem to be offset to the left side of the bike, both front and rear have similar offsets. Is this normal, possibly for sidecar?

Basically, whoever has an r25/2, please help this newbie with some tips on what to look out for with this bike. My wife wants to kill me already and its only been at the house for a day

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'52 R25/2

schrader7032
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Well, I have an R25/2 and

Well, I have an R25/2 and it's been thoroughly gone over including a recent engine rebuild by Vech.

As for torque, the long bolts thread into the cylinder. With torque being reduced, among other things happening, your valve clearances will be closing up. Are seeing that happen too? If you're losing torque quickly, it's either that the head is squishing or the bolts are not catching in the threads in the cylinder...maybe they're stripped? When I had the engine done, it was initially torqued by Vech. I might have just checked them to be sure. After the first 100 miles or so, I rechecked torque. I'll probably recheck again around 500 miles. But I've not noticed much change in the torque. The head gasket will compress, but only so much. If the bolts won't stay torqued, you probably have some serious metallurgical issues.

To test the generator, the first step is to get a good voltmeter and hooked it to the battery terminals. You should be well over 6.5v, probably closer to 7.0v at the battery with the engine RPM at near cruising speed. Just rev the engine in your driveway while watching the voltmeter. If you're not getting the right voltage, then it gets harder to see where the problem is, but there are checks.

What do you mean by offsets in the wheels? Do you mean that the wheels are not centered between the front forks or under the fenders? They should be. You may have to take some pictures and upload them here.

Not sure what to say to look for. I would be mindful of all fasteners and things attached to the bike. I've had a couple of items depart the bike while underway...the bike vibrates quite a bit and so I try to check things over quite often to be sure it's all still tight.

Good luck!

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

ringerbeem
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Hey so I tested at the

Hey so I tested at the battery while I was running the engine and I'm getting 6.2 volts. I'm going to try again later just to be sure. If that's the case and it is 6.2 volts it's obviously low charge rate.

Also, I have to change my oil because there's some fuel in it from when it wouldn't start, I guess it seeped through the rings. Is there any oil filter or catch screen that has to be cleaned ?

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'52 R25/2

schrader7032
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Right, 6.2v isn't going to

Right, 6.2v isn't going to cut it. Check your brushes...they could be hung up and not making contact with the rotor.

No filter in the pan, but there is a screen. There will be a gasket between the pickup screen housing and the extension, so you might have to replace that if it is destroyed when removing.

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

ringerbeem
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On second test I get the same

On second test I get the same result, 6.2-6.3 volts. I checked the generator and the brushes, everything seems intact. Should there be clearance between the brushes and the armature or none? are there any continuity checks or voltage checks within the generator that I can do?

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'52 R25/2

schrader7032
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The springs on the brushes

The springs on the brushes should push the brushes down onto the armature...no gap. Be sure the armature contacts are not greasy and also be sure that the gaps between each set of windings are not filled with debris. They need to be scraped out...carefully.

Does your charge lamp work? Doug Rinckes has a very good book out to troubleshoot the charging system. Could be your voltage regulator is not working...there are some extensive tests to check it out. If this is the problem, you're going to need to get some local help to work through it I'm afraid. There is a free version Understanding and Maintaining BMW /2 Electrical System, but it might not be as detailed as it needs to be for the R25/2.

http://www.snafu.org/restore/links.html

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

ringerbeem
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I think I've solved it, I

I think I've solved it, I found the voltage regulator screw and adjusted it. I'm now charging around 6.7 volts

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schrader7032
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Sounds great. I suspect the

Sounds great. I suspect the screw adjusts a gap. But 6.7 will almost do...you may need to find a battery tender for a 6v system.

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

ringerbeem
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its going to 6.81 at higher

its going to 6.81 at higher rpms, i can probably tweak the nut to get 7. Also with regards to my front wheel i am attaching some pics. So basically as it is, i am missing the axle nut and waiting for the front brake plate because my original is cracked. But as it is put together it is off center, I cant say how it will be once i can tighten the axle nut. The shocks when extended fully are the same length (well within 1/8 of an inch)

Thank you very much for all the help, Im going to bust my mechanics' balls on monday

  • img_0660_1.jpg
  • img_0662_1.jpg
  • img_0661_1.jpg
  • img_0652.jpg
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'52 R25/2

ringerbeem
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wheel has new guts and spokes

wheel has new guts and spokes fyi, and the axle is in all the way. I cant say how the wheel sat before the resto because i received the bike in pieces

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schrader7032
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6.8v is very nice...I'd stay

6.8v is very nice...I'd stay with that for the time being.

I am not by my bike now, but I don't see the brake actuation lever on the right side of the front hub...and there's a large bolt/nut at the top...that doesn't look stock. I'm wondering if your brakes are too wide and the wheel and brake housing are not sliding together as far as they should. If the wheel were to slide more towards the right side of the bike onto the brake housing, that might make up the difference. I'll have to look at mine tonight.

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

ringerbeem
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The brake plate s just

The brake plate s just sitting on there, I'm waiting for brake parts for the front. No pads right now or brake key and lever

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'52 R25/2

schrader7032
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Here's a picture of my front

Here's a picture of my front wheel. It appears that your axle is not in all the way and that the wheel is not properly seated against the brake housing.

  • r25rightfrontaxle.jpg
  • r25leftfrontaxle.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

ringerbeem
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I just have to wait until I

I just have to wait until I get all my parts in, then I'll know for sure. Also just a question about the rear shocks, how much grease are they supposed to take?

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'52 R25/2

schrader7032
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Rear shock grease...not sure.

Rear shock grease...not sure. I recall hitting them with my grease gun but don't recall how much. I haven't touch them since I got the bike several years ago. A couple of handle pumps to start with and go from there??

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

ringerbeem
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I noticed that when looking

I noticed that when looking at the bike from the front, the right shock is 1/4 inch longer than the left, which might explain the way the wheel is sitting. Any suggestions? Should I replace the springs?

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'52 R25/2

schrader7032
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Well, they shouldn't be

Well, they shouldn't be offset like that. Sounds like you need to dig into the forks and find out what's going on.

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

ringerbeem
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Bent fork slider

I took my forks apart and have found that the left fork slider is bent. Can these be repaired at all?

  • img_0717.jpg
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'52 R25/2

schrader7032
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There are frame straightening

There are frame straightening places in the US. Might be worth a check. At least you could get a professional opinion as to the safety of doing such a thing.

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

ringerbeem
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Clutch

I have about 100 kms on the bike now and I have a clutch issue. While riding yesterday I noticed that while changing gears the clutch remained partially engaged. I tightened the cable a bit and the problem was solved. After i parked and started the bike again to leave, my clutch would not disengage no matter how tight the cable was. Nothing seems seized from the outside, the plunger moves about 3/16 of an inch. In first gear with the clutch lever pulled I am not in neutral. Any ideas?

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'52 R25/2

schrader7032
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I did a measurement on my

I did a measurement on my R25/2. I didn't measure at the plunger or pushrod if that's what you were talking about. I measured at the lever end where the cable fits into the end of the lever. The lever end moves about 3/16" (or 5mm) in free play and the total movement (with the hand lever all the way in) is about 9/16". What does your lever move? If only 3/16", then that would clearly say you're not getting enough movement to disengage the clutch.

You might have some cable stretch and you just need to readjust the clutch cable. I replaced most of my clutch components on my rebuild and I had to adjust the clutch a couple of times as things wore in.

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

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