Loud rattling then engine stopped...

[Steptoe]

Had a non-running bike arrived on a trailer.

Long story short. Owner had a flat battery, jump started bike, left to warm up.
Then it was ridden and a rattling noise appeared.. Got louder and then the bike stopped.


Found a dislodged valve seat which was stopping the valve from sealing when closed. But with no apparent valve or piston damage.

 

[DrFarkoff]

Right hand side again ??

 

[Packer]

Looks like it from the plug holes and valve sizes.

Maybe left to "warm up" for too long. What do BM recommend? Something like start and ride away immediately?

 

[Yellow Peril]

Looks like it from the plug holes and valve sizes.

Maybe left to "warm up" for too long. What do BM recommend? Something like start and ride away immediately?

That's what I have always done, seems to be the best bet.

 

[Steptoe]

Run a gauge over the valve, it isn't straight .......

Call BMW, gave them chassis and reg number.... There are two sizes of valve depending on the valve guide length and they can't say which one this bike has, and there are none of any type in the country... The head is at the engineering shop waiting to have new valve seats made, inserted and cut.

Nothing is ever straight forward where BMW's are involved.

 

[Packer]

Germans that haven't recorded every detail of the specification of every bike. Surely not.

You're having a giraffe!

 

[Deleted account 211025001]

Is the other (inlet?) valve really that white?

Andres

 

[Nice 'n' Fat]

Germans that haven't recorded every detail of the specification of every bike. Surely not.

You're having a giraffe!

It'll be a Turkish workers fault, I guarantee it .............. it always is

 

[DrFarkoff]

Exhaust Valve Andres

Yup that white is as you see it

They usually have a creamier colour but now you see why the fall off they run as lean as fuck! And Consequently get as Hot as Fuck too!

Is the other (inlet?) valve really that white?

Andres

 

[Shep]

What made the engine stop???? I can see the rattle but not what stopped it, do you think the electronics can detect exhaust fumes in the inlet tract perhaps?

 

[daytripper!]

That's what I have always done, seems to be the best bet.

Errr, fine when starting off but what about waiting at some roadworks with say 3 way control traffic lights that are taking forever?

 

[Steptoe]

What made the engine stop?????

No compression. The valve seat was dislodged at an angle so the valve couldn't close.

 

[Bendy toy]

Leaking exhaust valve = poor compression = poor or no combustion. Lambda sees unused oxygen. ECU sees that as excess O2 so turns down the fuel supply. Engine stops

I'm now running a Power Commander. Exhaust pipe headers are grey inside rather than nearly white. Fuel mpg is down only 1mpg and bike is much nicer to use.
I've always used posh petrol as that also reduces exhaust valve temperatures.