The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Ian_N on April 19, 2009, 04:00:21 PM

Title: Should a 79 flywheel look like this?
Post by: Ian_N on April 19, 2009, 04:00:21 PM

Hi all
My bike has a 79 frame and an 82 engine. the air box is the older style, as is the clutch release arm. The rest is a mystery!

I stripped the clutch today to find the clutch cover as attached. the flywheel is also shown.

I was a bit baffled because, contrary to both haynes and clymer manuals the clutch cover plate bolts were 6mm not 8mm.

Before I attempt to buy a new friction plate - does this look like a circa 1979 clutch and flywheel?

Also - the two metal friction surfaces look - how do I describe it? Sort of dimpled. Is this normal? I couldn't take a picture - nothing I have on a digital camera focusses that close! It is very even, so I'm assuming it is a) deliberate and b) unworn

Thanks

Ian

Title: Re: Should a 79 flywheel look like this?
Post by: Bob_Roller on April 19, 2009, 04:24:14 PM

You have a 'first generation' clutch pressure plate, and flywheel.

So if you replace the parts, you need to get the same parts.

I'm not 100 % sure, but I think the transmission dictates the use of the 'first gen' clutch assembly.

Title: Re: Should a 79 flywheel look like this?
Post by: steve hawkins on April 20, 2009, 06:03:28 AM

Watch out when you torque up them 6mm bolts - see the facts area - torque setting are incorrect in manuals.

Steve H

Title: Re: Should a 79 flywheel look like this?
Post by: Ian_N on April 20, 2009, 03:45:11 PM

Thanks. I did notice that they appeared to be just pinched tight when I undid them.

Title: Re: Should a 79 flywheel look like this?
Post by: Semper Gumby on April 20, 2009, 10:09:15 PM

Use no more than 6-10 ft-lbs.  Better to use 6 and some blue locktite.

Oak says that the BMW guys never got around to finishing that chapter in their service manuals on the 1979 and 1980 R65.  In September 1980 they changed to the light weight clutch with the bigger bolts and forgot about the past.  We are left to remember!!!!

TTFN,

Title: Re: Should a 79 flywheel look like this?
Post by: vestandpants on April 21, 2009, 12:44:27 PM

ian,

I tightened the bolts up according to the manuals and destroyed a few in the process. The tensile strength is a lot lower than the manual is suggesting or what BMW supplied with the new bike back in '79.

Mine is a '79 ...

http://www.flickr.com/photos/22686607@N06/2915379559/in/set-72157607768641983/

and here with the plates in place:

http://www.flickr.com/photos/22686607@N06/sets/72157608455505925/

Title: Re: Should a 79 flywheel look like this?
Post by: Ian_N on April 21, 2009, 02:25:59 PM

Excellent pictures - they encourage me to do mine properly.

I got a bit sidetracked by the pictures of the big, 10 wheeled vehicle. Now that is a real project! A bit before my time, the Bo-Cos.
Where are you doing that work? I had a nose around the Bodmin and Wenford last year where they are restoring a 33 and various shunters I didn't recognise. Near me at the Avon Valley Railway, they mostly seem to drink tea...

Title: Re: Should a 79 flywheel look like this?
Post by: vestandpants on April 22, 2009, 02:08:38 AM

thanks for the comments,

the co-bo and the 15 are being restored at the east lancs rly in Bury and the kettle is never cold!

Title: Re: Should a 79 flywheel look like this?
Post by: Rob Valdez 79 R65 on April 23, 2009, 02:54:23 AM

So apparently I will have no problem bolting up my '79 flywheel to my new '81 engine!  Good news. :)

Title: Re: Should a 79 flywheel look like this?
Post by: Barry on April 24, 2009, 02:07:43 PM

Masson

I had a ride up to the Classic bike meet at the East Lancs Railway on Easter Sunday.   If you are one of the guys that keep those trains running it must be a labour of love.  I was truely in awe of the engines.
I noticed the Engine Drivers still brewed tea in the old enamel billy can. Nice touch.

Anyone one from the UK who reads RealClassic could this be Frank Westworth a long way from home

(http://)

Title: Re: Should a 79 flywheel look like this?
Post by: Justin B. on April 24, 2009, 04:05:32 PM

Looks kinda like Santy Clawz to me...

Title: Re: Should a 79 flywheel look like this?
Post by: Barry on April 25, 2009, 04:05:08 AM

Back on the subject of flywheels - do all R45/65 flywheels have the same number  of teeth.  It would be useful to know for making small adjustments to ignition advance/retard.

Snowbum says airhead flywheels have either 93 or 111 teeth depending on the starter being 8 or 9 tooth. From the photos posted I count something in between maybe 107. Does  anybody know the exact number on a 79 flywheel?

Title: Re: Should a 79 flywheel look like this?
Post by: vestandpants on April 25, 2009, 04:23:10 AM

I must admit i have no idea, I thought the flywheels between revisions had the same amount of teeth.

on a side note, It certainly is a labour of love Barry, one that has made me slightly deaf in my left ear (according to a medical i attended yesterday), all that needle-gunning and grinding rusty metal  ;D
I'd be up there this weekend if it wasnt for wanting to get mine finished and it's so very nearly completed  ;)

Title: Re: Should a 79 flywheel look like this?
Post by: Ian_N on April 27, 2009, 03:37:53 PM

Just counted - twice
There are 111 teeth on this flywheel

Title: Re: Should a 79 flywheel look like this?
Post by: vestandpants on April 27, 2009, 03:42:43 PM

Ian, you have to much patience and time to count every tooth!

Title: Re: Should a 79 flywheel look like this?
Post by: Barry on April 27, 2009, 05:20:15 PM

Thanks Ian

Snowbum was right then.

1 tooth advance or retard will be approx 3.25 Deg

Title: Re: Should a 79 flywheel look like this?
Post by: Semper Gumby on April 28, 2009, 07:10:33 AM

Quote

Use no more than 6-10 ft-lbs.  Better to use 6 and some blue locktite.

Oak says that the BMW guys never got around to finishing that chapter in their service manuals on the 1979 and 1980 R65.  In September 1980 they changed to the light weight clutch with the bigger bolts and forgot about the past.  We are left to remember!!!!

TTFN,

Use 7.5 ft pounds (88 inch pounds) and some blue locktite.  Read hint in this Snowbum file:

http://bmwmotorcycletech.info/clutch.htm

TTFN,