The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Peter77 on November 07, 2011, 10:16:30 AM
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Hi
I am rebuilding a R65 from bits and I doubt if I have the correct number of engine to frame spacers. I have 3 spacers 6 mm thick (1/4 in.) and I think one is missing one as 4 would be more obvious.
Would someone check on his bike and let me know.
Many thanks
Pierre
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My bikes have a single spacer on each side of the engine 6mm looks about right .
I think the amount of spacers is not the critical factor, they are in there so you don't stress the frame when you tighten the nuts on the engine mount bolt/threader stud .
So use the amount you need to so there is very little gap, if any before you thighten it up .
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Thanks Bob
It sounds logical. So two at the front and two at the back.
Must get hold of a spare one now.
Pierre
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I'm wondering if this can even be ordered. Seems I remember discussion from a long time ago that this part either was pictured but no part number (like the perch wedges) or was on a page in the parts fiche that was seemingly unrelated so extremely difficult to find.
If there would be enough interest I could turn out a batch of SS ones...
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the spacers are number 46712311727
What's the difficulty? was easy to find at MAXBMW fiche.
$1.03 each
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When I got my LS it was missing one of the spacers. The PO had installed a rubber bushed spacer that Luftmeister sold for a while. The rubber bush disintegrated and left not much else. I got a stack of ss washers the right thickness ( I think 5 or 6) and shrank some heat shrink around it. Been working fine ever since and has the added benefit of looking like a part of the frame (black shrink wrap).
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This part hasn't been available from BMW for quite some time .
This is the first time I have seen a part number for it, up to now, there was a reference number on the illustration, but it wasn't listed with a part number below it .
I installed the Luftmeister rubber isolators about 28 years ago and it was stated in the instructions, to keep the spacers that came out, because they were not available from BMW if you lost them .
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the spacers are number 46712311727
What's the difficulty? was easy to find at MAXBMW fiche.
$1.03 each
I guess you're smarter than me. I couldn't find them in my ETK...
Forward all parts-lookups to wirewrkr... ;)
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I have the part number for the replacement rubber bushes for the luftmeister anti-vabration kits. The rubber is a 'power transmission' part manufactured by David Brown and avilable from engineering suppliers. If anyone needs to replace them I will look up the number.
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Those rubber spacers were a poor idea from the beginning. For one, the engine is an integral part of the frame, and without it clamped securely, the frame can flex much more than it should. Handling will suffer.
Secondly, without the solid spacers, the frame can be drawn in tighter and possibly break at the mounts. Not uncommon.
Thirdly, they don't really eliminate vibration - the best solution is a good tuneup. Attack the problem at the source, don't mask it!
I'd caution not going there, and either return the bike to stock with the solid mounts, or don't ever install them in the first place!
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I've never tried the rubber spacers myself, but I have also heard that they tended to be detrimental to handling/frame stiffness so I've never considered using them.
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Don't waste the money and effort to install them, they really didn't do anything to help the vibration band that is prevalent with the R65 .
I think a good carb synchronization would be time better spent myself .
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Thanks for that feedback. Next time I have the headers off I will change them back to the steel spacers.
I still have them even though the rubber ones have been on the bike for 20 odd years.
I will be interested to see if there is any noticable difference in handling, (and the buzz) not that I've had any problems.
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I can't even feel the vibration band anymore, when I first got the bike, it felt like a switch was turned on when the vibration started, it was that pronounced .
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Bruce
If you are going to work on the engine mounts you might want to re-visit this thread, started by bangpaul. The lack of responses at the time suggest it might have been perceived by some as something akin to snake oil. I was a believer though and still am.
http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1311767047/7#11
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Bruce, please post the thickness of the stock bushings if convenient. I need to make a set for wife.gov's bike as hers came with the aftermarket rubber jobbers...
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Thanks Barry, I had a quick look. Do you recommending 50 lb/ft front and 45 lb/ft rear mount? Or did you find a better setting for your bike?
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Hi Justin, The spacers are 22mm O.D. x 13mm I.D. x 5.75mm thick.
I measred the thickness with a manual micrometer.
Cheers
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50 lb/ft front and 45 lb/ft rear mount? Or did you find a better setting for your bike?
I finished up with 45ftlbs on the front and 40ftlbs on the rear which although they seem low are still higher than the torque specs for 85 on bikes. I suspect the best torque settings may vary from one bike to another though.
I noticed no effect on handling but leaving that aside I was fully convinced that engine mount torque settings had perceptible effects on perceived vibration levels. My explanation of why this might be was the engine and frame work together as a structure and variations in the torque settings alter the resonant frequency of that structure so the high rev vibration period is diminished or at least moved to a different part of the rev range. In my case it was diminshed and moved up.
Another technique I heard of but never tried was to tighten the engine mounts with the engine running.