The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: AlfromNH on April 09, 2014, 07:34:02 PM
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My Clymer manual lists motor oil capacity of 2500cc. I put that much in, and after running the engine for a while, it read high on the dip stick. Does anyone have a different spec for a '79?
Also, the Clymer manual covers a wide range of airheads, but only states a valve clearance of .004" for intake and .008 exhaust. Are those the right numbers?
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This is from the BMW shop manual, oil volume without a filter change, 2.0 liters, with a filter change, 2.25 liters .
This is for ' first ' generation R65's, '79-80 model year bikes .
I'm not sure what the general guide line is for cold valve clearance, I had my cylinder heads reworked and the shop said to run .008 in. intake and .010 in. for exhaust, due to the aftermarket valves that were installed and the hot environment that I reside in .
I have heard oweners running .006 intake and .008 exhaust .
I'm sure you will get a variety of answers for this .
When you are checking the oil level, are you screwing the dipstick all the way in, or just let it sit on the engine case ??
Proper oil level check is with the dipstick sitting on the engine case, not screwed in .
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I was checking the oil level with the dipstick resting in the hole, not screwed in. Thanks for the clarification, 2ltr sounds about right.
I've set the valves to .004/.008. There seems to be a fair amount of clatter, but being this is my first airhead, I don't know what "normal" is. Doesn't sound bad tho.
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I just ordered the BMW Rider's Manual from Motobins. I know it's not a service manual, but in some ways it will be a step up from Clymer
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There were some variations in the sumps of the various models, but the early R65s did have a fairly shallow sump, so I think approx 2 litres is about right - ideally you want it to be in the middle, between min and max, to minimize the amount of "pumping" that can happen with longer, sustained, high speed rides - the crankcase pressurization from the pistons moving in and out tends to pump a bit of oil up through a breather/crankcase gas valve and into the carbs for burning - keeping the oil at mid-level seems to be where these engines are happy and stop pumping oil up there. You are doing it correctly with the dipstick cover unscrewed and resting on the whole to take the oil level measurement.
I run my valves at .006/.008 - I think this works well and matches what many other airhead riders use. It is slightly tappy, but not too loud. As you will hear from BMW riders, "Tappy valves are happy valves". Within reason, of course.
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Is the rider's manual the same as the owner's manual? It's got tons of great info, including valve lash, fluid capacities, full wiring diagram, etc. Add some torque values to the notes section and it can serve you quite well.
.004 on the intake should be fine, and a little bit quieter too. It's the exhaust valves that you don't want too close.
Excessive rocker arm end play can make the clattering louder... but even a nicely tuned airhead makes a whole lot more racket than the sewing machine bikes. They made a T shirt for it; it says, "loud valves save lives."
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As I mentioned in the recent 1st oil change thread a 78-80 models have a lower sump capacity of 2.25L vs 2.50L of the later models. In practice no more than 2.0L is ever required because you don't want to run at the maximum mark on the dipstick.
The other difference in oil capacity is 250cc vs 350cc in the final drive. Everything else is the same for both models.
Valve clearances have a bit of history and to summarize what I've seen in print:-
78 -80 owners manual inlet .004" Ex .006"
81 owners manual inlet .002" Ex .008"
Mar 82 Service bulletin inlet .004" Ex .008"
In truth it's not that critical as long as both cylinders are as close to the same as you can get them. I choose to use a very tightly set .006" and 0.010" and notice no significant increase in noise over other settings. The most important thing about valve clearances is to adopt a consistent and repeatable method so that you will know if they have changed at the next service. If the settings are accurately recorded it will allay any fears of valve recession. I've never seen a measurable difference from one service to the next, maybe half a thou at the most. So for me at least valve recession is a myth.
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I have the downloaded Rider's(Owner's) manual, but it's '81+ I believe.
I love the fact that BMW gave its owners enough credit to provide them with things like valve clearances. 8-)
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Those tappets produce what is often referred to as BMW Music. Get used to 'em. They'll often give you early warning of a potential problem.
Bored at home with absolutely nothing to do? Run the tappets and compare clearances to your last lash settings. Good therapy... for the bike and you.