The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Redbaron on August 11, 2025, 03:27:23 PM

Title: Where is TDC?
Post by: Redbaron on August 11, 2025, 03:27:23 PM

1980 BMW R65.  I just replaced about all the electrics and need to find TDC.  This photo from another post shows where it is suppose to be but I dont see it.  I do see two (2) holes drilled into the flywheel.  I would appreciate any suggestions about tools or techniques you use to find TDC.  Thanks Jeff

Title: Re: Where is TDC?
Post by: dogshome on August 11, 2025, 11:29:36 PM

OT is tdc. The yellow line.

Z is full advance. The white blob means someone checked timing with a strobe in the past.

The clutch is different to mine, which has stamped markings and very little flywheel (1983).

Title: Re: Where is TDC?
Post by: Barry on August 12, 2025, 02:34:37 AM

Your flywheel is the same as my 79. Two holes for static and full advance and a line for TDC or OT as they call it.

This is what you should see through the timing hole. Note timing should be referenced to the chisel mark on the side of the timing hole which in my case is not central.


The flywheel on a type 248 is smaller in diameter so there is an increased risk of parallel error. If you sight square on to the casting surface -  yellow line there will be an error. The correct alignment is slightly above - blue line to allow for the thickening of the casting.

Title: Re: Where is TDC?
Post by: Redbaron on August 12, 2025, 07:42:02 AM

Thanks again Barry and I can see all the marks!