The Good Old Missing One Cylinder Plywood Fix

[MichiganBob]

I've heard from at least four different guys how a rider crashed or for some mechanical reason removed the connecting rods, etc., from one side of the Beemer, fixed a plate or plywood board to it and chugged on home. What do you think? Truth or urban legend? Anyone experience this? Would it work?

 

Michiganbob

[Oldrider51]

Never heard of this being done and would think that if the piston and rod were removed and if it would even start it would shake SO BAD that one could not ride it. Might work better if the fuel could be stopped and the spark plug removed along with the ignition components for that side then it might work, less shaking with the piston and rod still attached. Just a guess.

[wbw6cos]

Displacement On Demand?  

[szurszewski]

My first BMW - and R60/7 - used to do that on its own. Not the partial disassembly thing, but the shutting down one cylinder thing. You could still ride it that way if you had to, but it was a *little* underpowered...

[Joe Frickin' Friday]

On 10/29/2021 at 3:51 PM, MichiganBob said:

I've heard from at least four different guys how a rider crashed or for some mechanical reason removed the connecting rods, etc., from one side of the Beemer, fixed a plate or plywood board to it and chugged on home. What do you think? Truth or urban legend? Anyone experience this? Would it work?

 

Michiganbob

 

Seems unlikely.  To remove the con-rod from one cylinder, don't you have to have the other cylinder off to access the rod cap bolts?  Here's the rod from an R1100 engine:

 

 

Basically, you'd be pulling the good cylinder off in order strip off the parts for the bad cylinder.  A lot of work, and you'd need a new head gasket for the good head to put it back together. 

 

I wonder how well it'd breathe, with one exhaust header open to atmosphere?  

 

 

[The Fabricator]

AND the oil now pumping out the con rod hole in the crank pin AND the oil passage to the top end would seriously drop the oil pressure,  which could be a problem. Plug them up.

THEN the cam chain.  Cut it off.

Disconnect the power to the injector.

 

As for needing NEW head gasket after removing good cyl to access rod rod bolts......doesn't seem like too much of a compromise for a guy willing to use plywood.............might make do with the old one.

 

I have. Used copper coat. Paint would work too.  

 

Now I have 2 new oil head gaskets 'in stock'.

 

It would be feasible.

 

Never heard of it.

 

 

[MichiganBob]

So the consensus is that a BMW twin will not run down the road with one cylinder missing and the space boarded up. I've been wondering as I've heard this a few times in different circles when I lived in Kansas, New Hampshire, and Michigan. It was never from the person who did it but was a friend of a friend or my uncle knew someone .. which is the basis for urban legends.