The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: NorR65 on March 05, 2010, 10:58:00 AM

Title: Valve adjustment - R65 1981
Post by: NorR65 on March 05, 2010, 10:58:00 AM
I have adjusted the valves a month ago.
But I am not 100% sure I did it the right way. I could not see any OT or other markings on the flywheel. On an older BMW I would look for OT. I removed right cylinder spark plug, observed when the piston was on top, both valves was closed and I could swirl both push rods.
Then I adjusted both both right side valves.
I have not started the engine after valve adjustment.
Any good ideas?
Thanks
Title: Re: Valve adjustment - R65 1981
Post by: Ed Miller on March 05, 2010, 11:41:45 AM
It will probably run the way you did it, but there should be an OT mark.  You have to be looking in the hole just right or it will be off to one side and not visible.  

Here's an article on the procedure:

http://bmwmotorcycletech.info/setvalves.htm

Title: Re: Valve adjustment - R65 1981
Post by: Bob_Roller on March 05, 2010, 11:54:30 AM
You just need to rotate the engine, until both valves are loose, or like you did rotate the push rods .

I remove the front cover off the engine, remove both spark plugs, and rotate the engine by the bolt that secures the alternator rotor to the crank shaft, with an allen key socket and ratchet  .

Don't know how long you've had your R65, but it's a good idea to check the torque of the nuts holding down the cylinder heads, every once in a while .

Especially if you've had the heads off of the cylinders .
Title: Re: Valve adjustment - R65 1981
Post by: NorR65 on March 05, 2010, 12:00:31 PM
I really will find the OT mark.

But my flywheel look like this:


http://www.realoem.com/bmw/showparts.do?model=0358&mospid=47850&btnr=21_0067&hg=21&fg=05

Where will I find the OT mark?
Thanks
Title: Re: Valve adjustment - R65 1981
Post by: Bob_Roller on March 05, 2010, 12:05:55 PM
There a small metal tags on the flywheel that have the marks on them, I would recommend rotating the engine slowly, either by the alternator bolt, or putting the bike in gear, and rotate the rear wheel, until you see them in the timing hole .

They can be a real difficult to see sometimes .
Title: Re: Valve adjustment - R65 1981
Post by: Mike V on March 05, 2010, 12:15:56 PM
NorR65,

You'll be looking for a mark similar to these...

http://i428.photobucket.com/albums/qq8/gruntyman66/81%20R650%20Restoration/Clutch%20Pack/81R65RestorationClutchPackAssemb-6.jpg

http://i428.photobucket.com/albums/qq8/gruntyman66/81%20R650%20Restoration/Top%20End%20Job/81R65RestorationTopEndJob005.jpg
Title: Re: Valve adjustment - R65 1981
Post by: NorR65 on March 05, 2010, 01:42:24 PM
Thank you for your help.
I will have a look for OT markings and check my valve adjustment again before I start the engine. Then I have to adjust and balance the carburettors.
My R65 have got at least 83.000 km and need some adjustments.
Title: Re: Valve adjustment - R65 1981
Post by: Rob Valdez 79 R65 on March 05, 2010, 06:06:23 PM
When adjusting my valves, I just turn the engine by hand, using a ratchet wrench with a allen bit on it, in the alternator bolt (remember to disconnect your battery before removing the front cover) until one piston is at TDC - using my drift from my tool kit, I feel when the piston is at the top.

On one side of the engine, you are at compression, with both valves closed.  This is the side you want to adjust, first.  Both rockers SHOULD have some free play on this side.
The other side should have the exhaust valve open (I think).

After you finish with the first side, move to the other side, put the drift in the sparkplug hole, and again, rotate the engine until the piston drops and comes back.  You should now be on compression for the 2nd side.

You can also use a plastic straw for a drift - that way there is nothing hard in there.  Someone once mentioned using a screwdriver, but it is possible to break something off in there.  The drift in the tool kit is nice and solid with a round head.  Go slow and you should have no problems.  The piston does move quickly in there!


A lot of folks use the rear tire with the transmission in 2nd gear to turn the engine.  I could never get comfortable with that.
Title: Re: Valve adjustment - R65 1981
Post by: Semper Gumby on March 06, 2010, 07:01:59 PM
For inquiring minds on the 79 and 80 models (pre 09/80) with the smoother running heavy flywheel (Small joke), the OT of the later model is a faintly stamped "0" followed by a 1/8" drilled hole for the "S" mark (there is no "S" -- just the hole) and then there is another similar drilled hole with the "Z" stamped next to it.  I have them all marked with white out to make them easier to see.   :o