To be concerned or not?

Had a look in the cylinder when I changed the spark plugs, and could see quite a bit of build up on the top the the piston... is this normal and is there anything that should be done?

https://www.evernote.com/shard/s622/nl/116066973/a4c9d3b1-e6a1-444c-b108-dc098f0d095c/

Had a look in the cylinder when I changed the spark plugs, and could see quite a bit of build up on the top the the piston... is this normal and is there anything that should be done?

Afternoon McDuugle

I can't tell much from your picture as there isn't a good contrast showing though the plug hole.

Is the carbon normal?-- Sort of. It shouldn't have a thick carbon buildup but a lot of old BMW boxer 1100/1150 engines do have some carbon buildup. (especially if they are now, or were oil burners)

IF you are worried then just run a hot engine cranking compression test with throttle held wide open & #5 fuse removed.

If compression is above high specs then you might have a carbon buildup to worry about.

Ok I will look into running the test, will need the right equipment first.

Also I have seen some people posting that they run their R1100RT at high RPMS all the time. I realized I barely ever make it over 4500RPM. I usually cruise at 3500 - 3800RPMS and shift up at around 4000 - 4200. When down shifting I usually down shift at around 3000 RPM. Varies a little from gear to gear but thats the gist of it.

Whats your take on this bikes comfort zone for RPMS?

Whats your take on this bikes comfort zone for RPMS?

 

Rode the piss out of my old (departed) 1150! Tried to blow it up once I knew she was a gonner/parting out. She wouldn't blow, just took off like a Bat outta you know where. Still have the engine, complete, in my shop.

To your question: Keep the Tach out of the Red, barely.

Ok I will look into running the test, will need the right equipment first.

 

Also I have seen some people posting that they run their R1100RT at high RPMS all the time. I realized I barely ever make it over 4500RPM. I usually cruise at 3500 - 3800RPMS and shift up at around 4000 - 4200. When down shifting I usually down shift at around 3000 RPM. Varies a little from gear to gear but thats the gist of it.

 

Whats your take on this bikes comfort zone for RPMS?

 

Afternoon McDuugle

Personally I don't buy into all that high RPM requirement. After all it is JUST a plain bearing, non overhead cam, large piston, somewhat long stroke boxer engine (nuttin fancy).

I don't recommend lugging it around in higher gears under 1800 RPM's but if it runs somewhat smooth without bucking, shuddering, or hesitating than you aren't hurting it.

Most of that carbon buildup that you (possibly have) is most likely from some older oil burning, not low RPM running.

Thanks DR, I have been told to run in higher RPMs as well; what you wrote makes plenty of sense.

I don't like high rev's on my 1150. I too, don't like lugging it.

It, for me, is about mechanical sympathy. The bike feels sweet at mid range revs (with a bit of ugly vibes in the 4500 (ish) range.

The more you thrash them, the more stress on components and it is just physics - they will wear/break sooner. (the same also is true for lugging the beast).