The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: castledener on April 09, 2015, 08:34:03 AM

Title: 1979-80 R65 UK model timing marks
Post by: castledener on April 09, 2015, 08:34:03 AM

Hi Guys,The timing marks on my R65 seem to consist of a shallow drilling for TDC followed by a small captive ball maybe 4mm in diameter for what would appear to be full advance.Is this the norm for the year of my bike ?.What angle or position do you hold the strobe to time the little beastie.This question has been bugging me for a few years now,maybe the forum can come up with the answer.Any help would be greatly appreciated

Title: Re: 1979-80 R65 UK model timing marks
Post by: montmil on April 09, 2015, 09:18:05 AM

Here's a good place to begin your research:

http://bmwmotorcycletech.info/F,OT,S,Z.htm

There's literally hundreds of reading hours worth of tech articles from The Snowbum's website. It can also be used as a fast cure for insomnia should you become afflicted.

http://bmwmotorcycletech.info/technical-articles-list.htm

Title: Re: 1979-80 R65 UK model timing marks
Post by: Barry on April 09, 2015, 02:14:37 PM

Your interpretation of the timing marks is correct. The static mark is a shallow drilling like this.

Your question about the angle is a good one because the R45/65 flywheel is smaller and therefore more deeply set than other airheads introducing the possibility of more parallax error. I went to some trouble to make a special tool that fits in the timing hole to ensure a more repeatable setting.  Basically I used the attached diagram to set the angle of the the pointer on my tool. What the diagram shows is that the correct sighting angle is not perpendicular to the engine casing as you might expect but a little higher. The error between the 2 is half a tooth or 1.7 Degrees.

Who knows what sighting angle the factory may have used when they applied a cold chisel to the side of the sighting hole to make the timing reference mark which is why I claim my method is repeatable rather than accurate.

If anyone thinks this is all a bit anal he did ask !

Title: Re: 1979-80 R65 UK model timing marks
Post by: castledener on April 10, 2015, 10:43:09 AM

Thanks Barry I set the timing using a higher angle.I'll see how the old girl runs

Title: Re: 1979-80 R65 UK model timing marks
Post by: castledener on April 11, 2015, 05:33:52 AM

Thanks montmil,there is a huge amount of info there...