The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: BigJohn on July 07, 2008, 05:37:19 AM
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Another post on a long discussed topic, but here I go. '81 R65, ? miles but let's say 75K. In my possesion for about 3 months. When I bought it there was no service history so I started at square one. The valves, as recieved, were reasonably quiet but I wanted to retorque the heads and check everything. Followed the owners manual and turned crank to TDC, compression stroke, set to .004 & .008 -they tapped pretty loud. I'd adjusted the pillars in with large Channel-locks so they had near zero end play but still very loud. I adjusted five or six times using the factory method but the noise always remained -TACK, TACK, TACK. Two weeks into this I tried something different. I slowly rotated the crankshaft until the gaps were the largest and then set them to the .004 & .008 size. This occured on each side at the point where the other valve was at its maximum opening. Said another way, when the left exhaust valve was full open the left intake valve had its maximum gap. The reverse was true for the full open intake valve, the exhaust was max gap. Both sides were the same. It didn't make sense but after adjusting all four valves in this manner they went tick, tick, tick and the bike ran pretty well. I've been riding the bike for a month at least with lash set like this and I'm pretty happy with the noises but why was I not able to use TDC as the adjustment point?
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You may have been 180 degrees out of sync but that's doubtful. Your second attempt is the right way for your BMW valve lash adjustment or on a Type-1 VDub air-cooled motor. Rotate the engine -using a high gear and turning the rear tire- while you watch the valve train go up n' down. As you did, find the high point and you'll be able to wiggle the rocker arm and confirm you are positioned properly. Pull a plug and peek in the cylinder... watch the piston for confirmation.
Tick, tick, tick. Bloody Marvelous!
Monte
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Elaine has a great article on how to set the valves on a /2 - the R65 is similar. Check out:
http://members.aol.com/vechbmw2/update3.html
Also remember - "noisy BMW valves are happy BMW valves"
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Hey that is the procedure for settin the BSA valves - Wait till the opposite valve is fully open. (easier to see on the BSA thou) You have probably been using the wrong mark for TDC (Top dead center)....
Tuning these bikes is an art so if it works then go with it! :D
BTW - I am amazed by the different numbers found in different year manuals for what is basically the same motor. (My heavy flywheel 03/1980 is .006 and .008)
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Hey that is the procedure for settin the BSA valves - Wait till the opposite valve is fully open. (easier to see on the BSA thou) You have probably been using the wrong mark for TDC (Top dead center)....
Tuning these bikes is an art so if it works then go with it! :D
BTW - I am amazed by the different numbers found in different year manuals for what is basically the same motor. (My heavy flywheel 03/1980 is .006 and .008)
Just this morning I wrapped up a re-torque of the heads and a valve lash adjustment on my R65. With the plugs out, valve covers off and trans in top gear I simply watched the rockers do their thing. Just for sport, I popped out the rubber plug that hides the flywheel timing marks and poked my MiniMag light in the opening... Thar be me "OT" marks! BTW, OT is BMW-speak for On Top or TDC.
Reading back topics here on the Disorganized Network and other web sites, I believe I read that BMW sort of settled on the .004 and .008 lash settings. That's what I'm using... anybody else?
Gotta get a new .008 leaf. Mine is s-o-o-o wasted from air-cooled Vdubs it looks like it's been worked by a mini English wheel.
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.004/.008 are the "stock" factory settings. some folks go up to .006/.010 - the valves will be a bit cooler, but might be a bit louder, that way though.
I run mine with .005/.009
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Hey Justin this "Valve Lash" thingy might have to go to the "Rant" section!!! ;)