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bstratton
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I now have about 200 miles on my R50 rebuild - restore

Motor was a complete teardown and rebuild except big-end crank bearings. I didnt split my crank. Saw no need because the play was non-existent

I have what I thought was an exhaust noise and just discovered my exhaust has no leaks at all. the noise is coming from my crank case vent. Sounds exactly like an exhaust leak. If I block it with my thumb it completely disappears

A: it is quite pronounced - Is that normal -
B: If not - any suggestions as to what I should be looking at

I believe there is a filter of some kind inside the air filter housing that leads to my crank case. I guess I could remove that temporarily and see if it makes a difference...

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Bstratton
1971 R60/5
1965 R50/2
MA

caker
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Philadelphia area (NJ)
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Hi, Engine breather

Hi,

Engine breather mis-timing issue (on the cam)? Is it also pushing oil out of every place?

Is the second breather port that goes into the airbox on the top of the transmission blocked? I think this uses intake vacuum to help with the timed breather pulses, and maybe would make more air go out the lower external vent if it was blocked.

Total guesses, here Smile

-Chris

schrader7032
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VBMWMO #7032
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Filter element on top of the

Filter element on top of the engine?? I thought that was an older system that was supposed to filter air that was passing over the electronics under the front cover. I didn't think it had anything to do with the breather. I thought the breather was designed to allow air to be pushed out of the crankcase when the pistons move towards bottom dead center.

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

caker
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You're right - was commenting

You're right - was commenting from memory (it's been a few years since I was inside my /3 motor).

Looking at some pics, the two "vents" are not connected. The lower vent is ported directly to the breather.

-Chris

wa1nca
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VBMWMO #8374
Ashfield Ma.
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Noisy crank case vent

That is a good sound
All is well

If you dont like it you can connect a hose to the vent tube add a pvc valve and then drill some holes into each carb to vent any mist and noise back into the intact manifold to dampen the noise and burn any hydrocarbons off

Again that is a good sound all is well

Tommy

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Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

bstratton
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Thanks

for the input. The filter I am referring to is a metal can the size of a mens wrist watch with a bunch of small holes that sits under a clip under the air filter housing. Part number 11 15 0 043 140 FILTER CARTRIDGE - Description is "breather filter"

Come to think of it - I never replaced that. Think I'll order a new one.

Sounds like this may be a non-issue. The motor runs fine.

  • breather_filter.jpg
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Bstratton
1971 R60/5
1965 R50/2
MA

schrader7032
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I'm surprised this filter

I'm surprised this filter is/was still being used...'65 model? At some point, the channel across the top of the engine was closed off during production and the filter was no longer used. My '69 (build in 1968) doesn't have anything there. I think that's what the small half-moon cover was there for.

-- Update -- I had an exchange with Duane. He says that the "filter cartridge" was continued until 1968 (probably calendar year) when it was dropped. My Apr/May 1968 built R69S doesn't have the cartridge. Seemed strange to me that so near the end of production, BMW would change the engine cases which meant a change in the design/molds for the engines. I can only guess that they might have done a cost/benefit analysis and found it cost effective to change the design rather than to continue with the old design and have to supply the filter along the way. Who knows!

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

wa1nca
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Breather noise

Yea not the filter

I think Caker is correct
Qoute
Engine breather mis-timing issue (on the cam)

Just found this from Ed Korns instrutions that came with my many in one tool kit

Qoute:
It is possible for the 2 pins on the breather plate to go into two of the large holes on the cam timing gear.
That is wrong they belong in the two small holes.
If they are in the wrong holes the engine will sound like a air compressor.

No need to remove the engine
remove the generator and magneto assy and then the front timing cover and then you can reposition the breather to the cam timing gear and reassemble

Tommy

  • cam_timing_gear.jpg
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54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

bstratton
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Yes 65

I will check my copious picture library to see if I can find anything that shows that part of the motor re-construction. This does, however ring a bell. I followed the Barrington manual to the letter when I put this motor back together. Hoping I didn't screw this up but if I did not the end of the world. I did order a new filter. Just because the original is probably from 1965.

Thanks for the research Tommy

Would there be any other potential damage being done if the breather plate was installed incorrectly

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Bstratton
1971 R60/5
1965 R50/2
MA

schrader7032
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The breather is supposed to

The breather is supposed to allow excess pressure built up in the engine cavity when the cylinders are approach bottom dead center. If the pressure can't get out, it will try and find any path out which could mean that seals at the front and rear of the engine as well as the pushrod tube seals were subject to the extra pressure. Time will tell if they were stressed enough to begin leaking.

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

bstratton
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thanks Kurt

I checked the Barrington manual and there is no mention of small vs big holes re: Duane's comment quoted by Tommy

Still, it is hard to believe I would miss the obvious relationship. I have no evidence that I didn't, though. I think I'll pop that filter out and see if there is any difference. If not I guess it means pulling the timing cover off and checking. Not the end of the world. There is no oil leaking anywhere. In fact the motor is surprisingly clean after a couple hundred miles with a mal-aligned breather plate.

Good stuff here. Glad I reached out. I'll let you know the outcome

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1971 R60/5
1965 R50/2
MA

wa1nca
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Breather plate

Would there be any other potential damage being done if the breather plate was installed incorrectly

I think not even for a longer duration

Tommy

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54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

Daves79x
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If

If your R50 is a '65, it would have had a breather plate with two rather large cast nubs instead of the one or two driven-in pins of earlier models. It is possible to confuse the larger holes in the later timing gear. You very well may have gotten the plate in the wrong holes. A bit of a tough fix though, as it's very hard to hold the plate/spring in position and get the gear cover on. Yours would not have the circlip holding the assembly onto the cam nose. Without that, you are left juggling the whole thing until it slips on. Take the cam seal out of the cover and get a selection of small screwdrivers and dental pics to hold it in place. On engines without the circlip holding the breather plate in place, they are meant to go together with the engine out and sitting on the bell housing, so gravity can help you. It works against you with the engine in the bike.

It took me an hour or two to accomplish this, but it can be done.

Dave

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wa1nca
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Breather plate

Just put my 54 R51/3 together last week
It does have the circlip for the breather plate so this is why I thought it should be easy
I can see why the one without the circlip would be more difficult but still possible without removing the engine

Tommy

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kfelt
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Puff Puff?

Skip, Is the sound you are hearing a distinct puff puff out of the breather tube? Listen to my R/69 next time we ride. You will hear it loud and clear.

bstratton
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video

Replaced the filter - no change

Here's a video with pretty good audio
Just don't want to tear into the engine for no good reason

https://drive.google.com/file/d/1Ho1mGsRjUfc1-UG1VVT13oNoOahhBW7T/view?u...

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Bstratton
1971 R60/5
1965 R50/2
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bstratton
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Circlip

I remember precious little about the details of installing the breather plate except I'm pretty sure there was no circlip(s) involved. The cast nubs sounds right. I did this with the motor on the bench so it would have been pretty easy to do.

If I do decide to do this I may just pull the motor. I'll have to go look at the manuals to see what gaskets/seals I may need to replace but my guess is both the crank and cam seals unless they come off with the timing cover and the timing cover gasket.

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1971 R60/5
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Daves79x
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No Harm

There's no harm in checking this with the engine in the frame. You really shouldn't need any seals or gasket if the engine has just been rebuilt. Get a new cover gasket though, just in case. You will need to pull the cam seal, so if that bothers you, get one of those also. Pull the cover, check the breather plate, pop the cam seal out of the cover before attempting to reinstall it. Then hold your mouth just right and you'll get it.

Dave

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bstratton
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Dave's topic from 2017

Dave, I see you had a similar issue a couple years ago. Very informative posts.

Kfelt (Keith) lives nearby and has a '56 R69. I'm going to listen to his and see if I want to take this any further. I just don't have enough experience with this motor to know if I am chasing ghosts. It vents differently than my '71 R60/5. There are no other signs of venting issues. Not a drop of oil anywhere and the oil fill behaves normally while running.

If anyone has listened to the video please comment on what you heard.

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1971 R60/5
1965 R50/2
MA

Daves79x
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FWIW

My '59 R50, with it's original single-pin breather plate in the proper position, makes no noise out of the breather tube. Can't say I've heard that on the several Earls fork bikes I'm familiar with either. I'd be looking for the cause.

Dave

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miller6997
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Ditto

I have never heard a lot of noise from the breather on my '67 R69S. Then again, I've never really stuck my ear down there to listen carefully either. I'll pay closer attention the next time I start the motor.

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Jon Miller
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schrader7032
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^^^ What he said! Seems like

^^^ What he said! Seems like the issue would be no puffs coming from the breather...of if it were sucking air. If there's air/puffs coming out, doesn't that mean that it is working?

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

bstratton
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Kinda what I was thinking

schrader7032 wrote:

^^^ What he said! Seems like the issue would be no puffs coming from the breather...of if it were sucking air. If there's air/puffs coming out, doesn't that mean that it is working?

Kinda what I was thinking, Kurt.

My plan is to compare it with my buddies R69s. If, as Dave suggests it is very different I guess I'll just have to do the work to confirm my breather plate is installed correctly. If it sounds similar I will leave well enough alone. I'll post the results either way
.
Thanks everyone for sharing your experience

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Bstratton
1971 R60/5
1965 R50/2
MA

wa1nca
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Noisy breather tube

did you have a chance to compare noise with the r69
PS
noise may be louder with new pistons and rings until break in

Tommy

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Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

bstratton
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yes

Keith's 56 R69 has not been torn down since he has owned it for slinger service so it is a little "looser" than my motor. My breather is louder but not by much. There is a similar amount of air coming from the breather tubes. There are no other symptoms so I am going to leave it alone and put some miles on it.... Once I get the new coil in it.

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Bstratton
1971 R60/5
1965 R50/2
MA

wa1nca
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Ashfield Ma.
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Noisy breather tube

That's good news

I had 2 bikes that started ok when cold but not after shutdown when warm
I worked in the inspection business for years and after getting my sticker my bike wouldn't start
I put the bike on the dynamometer in the calibration mode ran it up to 15mph and was hard to start but did
was supposed to help my son and his new girl friend move but aborted because told them I couldn't shut the bike down
2nd time that bike ran fine but died after 20 miles during a break in ride
Came home on a trailer

both bikes renewed the coil with the emerald island coil and all is well

Tommy

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Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

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