Vintage BMW Motorcycle Owners

Hello friends I recently re-assembled my 1957 R50 engine after seizing the right piston (not completely "seizing" but severely scuffing, causing piston slap) likely due to too tight of piston ring end gap, coupled with oil starvation (lack of oil hole on R side), then possibly exacerbated ...

So while both sides were running, I pulled the left spark plug cap and the RPM did not change. I incredulously checked the exhaust pipe and there was still some smoke coming out of it. The 11mm safety gap was sparking as well for the left side. I let it run like that for about 15 seconds. After I tu...

Hi There I recently completely restored a 1957 R50, which by the way, I find to be a very easy and comfortable ride. Personally it is powerful enough for me even though I'm a big guy 220lb. I don't take it on super highways and it is perfect for me- A true joy. I did want to mention that while I was...

Break in

Don't want to blame others but:
Against my instinct, I was advised by a BMW guru I trust to ride it long and hard on the break in...

I know its a controversial subject...

The next time I will try the easy-does-it route.

Break in

Don't want to blame others but:
Against my instinct, I was advised by a BMW guru I trust to ride it long and hard on the break in...

I know its a controversial subject...

The next time I will try the easy-does-it route.

Thanks Dave & Kurt!

Dave -would you hone the Left side as well and re-use the existing Left piston and rings?


Henry

What is the ideal spec? I may go to a different shop to get the cylinders re-bored to what I guess would be the 4th-over size which is 70mm. So my preliminary order of steps to take to solve this problem currently is: 1: rebore both cylinders to 4th over (70mm) 2: order 2 new 70mm pistons 3: change ...

Hi Folks -First Post on this forum, and it's good to be here! So...Over the past year, I restored a 1957 R50 (my first-ever machine restoration) - I made a Youtube video documenting the restoration: https://www.youtube.com/watch?v=eQXqBSgzs2M ..And another Youtube video of the very ride where my pro...

The mufflers being non stock are something I’ll have to look at. Come to think of it the original pistons I removed for the restoration had the same damage and used the same mufflers...That would be a pity as I love the sound of those non stock mufflers. But if changing to stock mufflers is what it ...

So they were new Kolbenshmidt 69.500mm pistons

Measurements of bore/ clearances for both sides as provided to me:

2.7345"
+.00197"
=2.73647