The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: mfrias2nd on March 12, 2012, 03:29:05 PM
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Hey guys,
I've had a leaky base on the right side of my '82 R65 (30k miles) I forgot to check the torque on the head bolts when I did my valve adjustment a couple weeks back. I'm thinking of going back in to give it a shot.
Would loose bolts/nuts be to blame for the gunky right side? or should I be considering replacing the gasket.
Always appreciate your advice.
-Mario
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To properly access all the head bolts, I believe it's necessary to remove the rocker shaft assembly. No biggie but the shaft does prevent getting a socket on a nut or two.
There should be no harm in giving a re-torque to see if it will slow down or stop the weeping oil. There is an Airhead school of thought about not re-torquing the heads too often. I'm not sure what "too often" is but advise not doing with every valve lash adjustment. Check your manual for the correct tightening sequence and values.
If the oil staining continues, a new gasket and o-rings may be in order. Don't know how you'd feel about doing both sides to establish a maintenance baseline...
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I consider giving it a shot. Eventually I'd like to do a full overhaul on the motor and since I'm just a weekend rider a little leak doesn't really worry me. However, can this leak lead to loss in compression?
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An oil leak at the base of the cylinder, usually requires replacement of the o-ring, or the push rod tube seals .
You can try checking the torque of the hold down nuts, 25 ft/lb of torque, I'm not sure what that converts to in metric units .
All of the nuts are easily accessible, the four that hold the rocker shafts, then the two outside the rocker box area .
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Thanks! The reason it even came up because while I was working on my R65 this weekend. I happen to notice that the left exhaust was really pumping I mean it was thumping hard and the right one was slightly weaker. Just wondering if perhaps I'm losing compression. and if so if the leak can cause loss of compression.
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I'm definitely in the camp of don't re-torque the head unless you have a good reason to. No point in risking pulling a stud out of the block which will be far more annoying than a minor oil leak. So if the leak is minor or just a bit of misting I wouldn't even consider it. As far as routine torquing of the heads is concerned, if the valve clearance don't close up between adjustments I can think of no earthly reason to risk it. Re-torquing should only be needed shortly after a re-build to take up any settlement of the gasket and you will see that as closed up valve clearances of a couple of thou.
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Thanks barry even better to know! what about my compression concerns?
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I'd carry out a compression test to see if there is a problem and if there was a low reading, carry out a leak down test to figure out what was causing it. I don't think it's that common for low compression to be caused by a leaking gasket.
Going back to the tightness of the head nuts I suppose I'd be inclined to just try the torque wrench on each of them at a low setting of say 20 ftlbs just to make sure none of them are seriously loose. It's not the right way to do it but it would be a low risk way of convincing myself that the problem lay elsewhere.
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A proper compression test requires the removal of the carbs from the cylinder head spigots.
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A proper compression test requires the removal of the carbs from the cylinder head spigots.
And a good strong battery. Don't be afraid to use a car battery. Just disconnect your smaller battery first.