The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: weasel01 on July 02, 2009, 06:26:08 PM
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Satisfied and empowered by my recent spline lube / boot replacement
success I'm moving on to the engine.
I want to re-torque the cylinders and adjust the valves...
I have read the clymer several times and also snowbum on this subject but have never done anything like this before.
Am I opening a can I wont be able to close or is it as straight forward as the rear end turned out to be?
Anything to look out for?
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It's a straight forward job, you do need a torque wrench to do the job .
I don't know what manual you are working from, but the cylinder head nut torque has been reduced from 29 ft/lbs to I believe 24 ft/lbs., and this is accomplished in three steps .
Also there is a torque sequence for the nuts, should be stated in your manual .
All of this, including the valve clearance check and adjustment is done on a 'cold' engine .
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I received my new rocker box gaskets today is there an inside /outside to those?
They are printed on one side but not the other?
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Also I dont have a feeler gauge set yet.
Is there a better choice in terms of brand or will a general purpose style be ok like from an automotive shop?
I already have a good torque wrench.
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Any kind of flat feeler gauges will work .
I don't think there is a left or right valve cover gasket, been 13 years since I got a set of rubber gaskets .
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If you guys have access to this months issue of BMW OWNERS CLUB OF AMERICA monthly magazine called BMW ON.There is a detailed step by step article with pictures no less, on how to do a valve adjustment the ''right'' way.It shows you how to tighten up rocker arm slop,retorque heads,then do the valve adjustment
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Is that a printed magazine or is it online somewhere?
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me do gooder with pictures...
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Its a printed magazine that is put out monthly by BMW owners of america club.I tell you, the magazine alone is worth the price of joining.A wealth of information is to be had.
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"I want to re-torque the cylinders and adjust the valves...Anything to look out for?"
You can do it, Ampy.
Like Bob said..."I don't know what manual you are working from, but the cylinder head nut torque has been reduced from 29 ft/lbs to I believe 24 ft/lbs., and this is accomplished in three steps. Also there is a torque sequence for the nuts, should be stated in your manual."
Lemme see here... Set .002" on the intakes and .004" on the exhaust. Disregard anything different you may read in the manuals. You want to end up with a wee bit of BMW Music. Tappity tappity.
No in-or-out side to the rocker box gaskets. And do be gentle with the center stud torque and the two 10mm nuts on each end of the cover. I don't use the torque wrench on mine. Just snug 'em up with a short-handled wrench.
IIRC, one of the cylinder head bolts is a bit difficult to reach. Seems the rocker shaft and associated stuff is an small obstacle.
Be sure to rotate the cold engine 180 degrees after setting the valves on one side! You can watch for the on-top mark through the timing hole near the dipstick. You'll then be able to rattle by hand and confirm the TDC valves.
Feeler gauge should be snug between the rocker tip and the valve head. Not crushed down so tight that you can't remove it. In removing the feeler gauge, a fairly firm yet smooth pull ought to be about right. It's something you'll learn by doing. Better a tiny bit loose than risking burning an exhaust valve.
Monte
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okay, I'm doin' it. I've removed rocker covers, loosened each head bolt in the appropriate pattern 1/4 turn, retorqued in 3 steps to 25ft/lb. have rotated back wheel and in fifth gear. watched the intake valve close, look in the hole in transmission. my question is...the is OT and then a line above OT, do I align OT or the line above OT with the mark on my transmission?
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.002/.004 sounds a bit tight, or it's been so long I can't remember...
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Oops! I believe I should have said .004 and .008 intake and exhaust. Ain't that more right? I looked at my smashed feeler gauge to confirm. Thanks, J.
Hey, Ampy... you catching this? :-[
OT is BMW-speak for On Top. As in, Top Dead Center (TDC).
Monte
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The owners manual I have says .006 (exh) and .04 (int). I think I have also seen .008/.006 mentioned elsewhere as well...
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So I did the deed last night...and it was straight forward but now I'm hung up on gaps.
My manual states .004 intake .008 exhaust.
So thats what I did I also torqued the nuts to 13 ft/lbs.
You guys mentioned .004 & .006
Snowbum recomends .006 &.010 for the R65?
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Just to muddy the waters a bit... It would appear that if you were to error on the valve lash setting, looser is better than too tighty. Of course, the BMW shop manuals are never incorrect on their specs? Now, let's talk tires! ;D Monte
This from Snowbum's site http://bmwmotorcycletech.info/setvalves.htm
"I set the clearances to .0045" intake, .0085" exhaust, with pressure on adjustor end to take up oil film slack. That is equivalent to an easy smooth fit for the .10 mm and .20 mm metric feelers, same for .004" and .008" feelers. The R65/R45 models probably should have the valves set a wee bit looser, .006" intake and .010" exhaust is fine. There is nothing wrong with using .006 and .010 on all the various models, actually, and a case can be made for some slight benefits, at the expense of a VERY SMALL amount of noise and potential wear." - Snowbum
New shooter coming out...
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It looks like there is a bit of wiggle room here probable be ok as long as they are in the range of .004 to .006 on the intake and .006 to .010 on the exhaust and just make it equal on both sides?
Sound reasonable?
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To add to the range of valve clearances that can be found in print my original Riders Handbook says .002" inlet and .008" Ex
I use .004" and .008" but would love to know what the theory is behind Snowbum saying R45/R65 clearances should be bigger than other airheads.
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I'm going to stick with .004 in .008 out...
I've seen that referenced more than the others...geez I hate that I'm not experienced enough at this to make decisions
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You'll be fine. It's so easy a caveman could do it. 8-)
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BMW actually changed the spec over the years and what you read differs depending on when your particular manual was printed. I think I quoted specs from a '79-'80 manual as the wiring diagram is labeled R45/65-78 and pictures inside show a round master cylinder.
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Well, I ended up with evenly torqued cylinders and .004 in .008 out
Put all back together fired it up and sounds way better than before the
valve noise is down 50% and the exhaust sounds throatier and cooler.
There seems like more power and smoother but I only took a 20 minute ride.
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Yea [smiley=clap.gif]
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.004" intake and .008" exhaust is the original factory spec - I tend to run mine closer to .006 and .010 - they are slightly more "tappy", but they spend more time in contact with the valve seats, so in my mind that may extend their operating life a bit longer (still on original valve seats which do not transfer heat well, problem solved in 1985/86, but all airheads in the 1980-1984 range have the potential for developing valve deformation due to inadequate heat transfer because of metallurgy issue with the original factory seats). The key thing is to get used to the sound they make, and check the clearance every few thousand miles to make sure the clearance isn't rapidly closing up on you - a sign of valve deformation and impending failure. A new set of BMW factory seats and valves, properly cut and fitted with new valve guides and keepers will have her set for another 100,000 miles.
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Thanks Monte!
You, Bob_Roller and Justin B. have been absolutely great in helping me out with polishing this ole' turd back into a cool bike and I really appreciate it!
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Nhmaf, I am a total greenhorn at this mechanics related stuff so bear with me.
My question is how does setting the valve adjustment looser give more contact time with the valve seats?
The way I'm understanding this the tighter they are set the longer each valve is open therefore more contact time? or am I way off?
Setting them looser uses part of the rotational cycle in travel time before contact and then again after the release?
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I found this and thought it sounded interesting I realize the r65 is not listed in the applicable models but it cant be too different cant it? :
BMW motorcycle valve adjustment procedures
by Duane Ausherman
This page applies to the BMW motorcycle models R50/5, R60/5, R75/5, R60/6, R75/6, R90/6, R90S and some later models.
Why adjust BMW motorcycle valves?
Valve adjustment is one of the most misunderstood maintenance items on the BMW. You are really performing a diagnostic function. For example, the engine will run very well with a setting of exactly zero clearance up to double the spec. With zero clearance, the valves will open a bit more and allow more fuel into the combustion chamber and that will make more hp, but you may not be able to measure it with a dyno. Really wide spacing will make more noise and not allow as much fuel into the combustion chamber, but again, you probably can't measure it. The wider clearance will make more noise.
The main reason to do the valve adjustment is to check for a change in settings from the previous time. If one or more valves are more than .001" off of where they were last set, you better make a notation in your log book. If a dozen people set your valves, they would each do it slightly differently. Which method is right? All are probably right. The important thing is to do it exactly the same from one adjustment to the next one. Then, any change shows you that something must be diagnosed to look for more serious problems.
If you find that the valves all still have a correct setting, this means that the heads are stable. If that is the case, then there is no reason to check the torque on the head nuts. All you will have done is remove the valve covers, check settings and replace the covers. And be happy.
If you found some change in the settings, then ask why? Reset them and check them again soon to see if it still changes. Find out why it is changing.
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My question is how does setting the valve adjustment looser give more contact time with the valve seats?
The cam has acceleration ramps designed into the component. Looser valve settings postpone lifter -to cam -to rocker arm -to valve tip contact; thereby allowing the valve to remain in contact with the valve seat a nano second longer, thus dissipating more heat... particularly important with the exhaust valve, hence the wider clearance gap setting/s.
Hope my lame explanation helps a bit. Monte
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He pretty much got "out of the business" before R65s came out. You'll notice that R80 and R100 are not mentioned either. The underlying logic in what he says still holds true. If the gap is appreciably changing then something is moving/wearing. Most R65 riders will notice the exhaust valve clearance getting smaller over time unless they have had a valve job and the exhaust valves and seats replaced.
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I think I was thinking about it backwards...it's not how long the valve is held open but how long the valve is allowed to stay in the closed position.
Staying closed longer keeps it in contact with the head or "heatsink" longer thus allowing it to run cooler. right?
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Roger that, Ampy. [smiley=thumbup.gif]