The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: 79beem on January 05, 2011, 08:02:00 AM
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Happy New Year to all R65 nutters.
My darling has a tap tap tap........... very consistant,regular noise above 3000rpm, which i noticed when i moved my legs off the tank to cool my........ well you know what i was cooling.
Anyway, i got quite a shock as i had'nt noticed this b4 but can now hear it without cooling system engaged ( legs on tank ).
Any ideas anyone on what this may be?
A friend, not a beemer owner ( ahem ) reckons i should'nt worry.
I'am going to check valve clearances first, but need clarification.
The clymer manual states .1mm exhaust and .2mm inlet.
Is this correct?
It also states re-torqueing head nuts every time , but i read on this forum only to re-torque heads once?
She's a lovely 79 model and i've put a 1000km ( full lube check / service prior ) on the clock this last week in my sheer unquenchable thirst and desire 4 the open road..............
I'm desperate to get her out there again but don't want to risk any damage if thats where i'm heading with this noise?????
Cheers
Ian
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The valve clearances, measured cold, are inlet 0.15mm/0.006" and exhaust 0.20mm/0.008".
You might also want to torque the heads once to make sure that they are right, as a starting point for your ownership. While doing this, you also want to make sure that the rocker arms are tightened up and don't have excess vertical play, which also can make the valves loud.
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The current spec after the BMW change notice dated (1982?) is .008" exhaust and .004" intake. I've been using .008" EX and .006" IN for years. I'm going to try .008 and .004 this next time around and see what happens. Also there may be too much up and down play of the rocker arms on the shafts.
The should be only about .002" of endplay between the rocker arm and the post at the end. If there is a bunch of play here the rocker arm will jump up and down "tapping" on the posts.
Too fix:
Look at the supect rocker arm's push rod. If the edge of the pushrod is really close to the wall tunnel, then loosen one of the two head bolts on that rocker so that when you sqeeze (coming next) the post together it pulls the pushrod away from the wall.
You need three or four hands for this next bit.
I bought a huge expensive monster set of plyers from sears with jaws that could hold the posts of the rocker arm between them just for this purpose.
Check and adjust:
To check:
First rotate the cylinder so that the valve is fully closed and the rocker arm is free. Put the .002" feeler gauge between the post and the arm and slide the arm up and down.
If there is play with the .002" feeler gauge in place then to adjust:
Keep the .002" feeler gauge between the post and the rocker arm. Put a torque wrench on the loose nut, and put some light gentile (think snug) pressure on the posts with the GIGUNDOUS set of plyers to squeeze them together. When you can just move the feeler gauge, tighten the posts headnut with the torque wrench. Check the valve clearence again when done.
Remeber if you clamp down hard with the GIGUNDUS set 'o plyers then you will wear out lots of expensive parts long before their time. There needs to be some play just not very much. When you are done the rocker arm should still move freely.
Repeat for the other three rocker arms.
Go out and ride it.
Also when you took off the valve cover there was oil there right? If the head parts are not wet with oil then you have another problem. :-[
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Opps!
Got those valve figures wrong way round.
Cheers for the prompt reply guys.
havent started yet but theres definately oil in them heads,( Leaky )
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Ian - one other thing to watch out for is valve recession. This is where the lip of the exhaust valve becomes too thin (actually sharp) with wear and the valve will sink deeper into the seat. Eventually the valve drops through the seat and gets launched at the piston. Impact destroys the valve (breaking the stem). The resulting cacohphony of a freerange valvehead destroys everything in the head quicker than you can reach the kill switch.
This can be seen by noting the valve clearence and writing it down each time you adjust the valves. If you see that the exhaust valve is tightning up everytime you adjust the valves then you need to have the heads rebuilt and better modern valves put in.
The Original exhaust valves of our 1979 -1980 bikes last about 50-70000 miles before this must be done. If its early days yet for your bike then just watch for it.
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There are shims available from BMW to take up the clearance between the rocker arm and support block .
They are originally meant for the upgraded rocker arms that have a plastic insert at one end .
I installed them on my '81 R65 75,000 miles ago, one shim looks like it needs replacing the last time I was in there checking the clearance .
http://www.realoem.com/bmw/showparts.do?model=0364&mospid=51897&btnr=11_1698&hg=11&fg=30
Item # 17 .
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As far as I know this is the history of BMW published valve clearances.
78 -80 owners manual inlet .004" Ex .006"
81- owners manual inlet .002" Ex .008"
Mar 82 BMW Service bulletin inlet .004" Ex .008"
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G'day Ian,
Worn valve guides will make a fair bit of noise. At about 170,000km my R65 was running well, but noisy. Then a valve stem broke. The guides had an extraordinary amount of wear. New guides, new valves - much quieter.
Cheers
Ray
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How many kilometers showing on the odometer? Any idea if it is accurate? (working, been replaced, etc.)
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Cheers for the input everyone,
Going to order shims just in case with the gaskets keep u posted,tackleing leaky forks this wkend, then maybe valves if i have time.
Rob, just passed 59,000.00, as far as i know its accurate.
Its not loud, but its definately noticeable when you move your legs off the tank.
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I don't really know what an R65 should sound like when running tight and sweet.
Is the only sound i should hear the muffler and no engine notes / noise?
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No, you should hear plenty of engine noise. Especially the tappets tapping. It's a good thing.
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Well i think thats what i have, tap tap tap tap.
What does valve noise sound like?
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A well oiled sewing machine .
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It's referred to as "BMW music". Crank it up! [smiley=thumbsup.gif]
Monte
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Maybe i should have asked,
How do poorly adjusted valves sound ?
How does it differ from the tap,tap,tap that i have now ??
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You actually have a lot of lee-way between too tight and too loose.
Too loose and you will lose power.
Too tight and you might burn a valve.
There is a poster on the Boxerworks forum that says he keeps his at zero clearance - but he checks them often...
Have you checked your clearances YET???
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No not yet,
I'am new to R65's and wanted to pick your collective minds b4 i started pulling her apart.
i'am going to on the wkend.
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When you adjust your valves, you need to rotate the engine.
Some folks put their transmission into 2nd or 3rd gear and turn the rear wheel.
I prefer to remove the front cover, and turn it with my 3/8" ratchet w/allen driver inserted into the alternator bolt. If you do it this way, remember to disconnect any and all ground wires from the battery before removing the cover (you can short out on the diode board, and possibly damage some diodes).
You also want to turn the engine in the direction of normal rotation, i.e. clockwise when looking at the engine from the front.
When working on one side, you want that piston at top dead center on the compression stroke. This will have both the intake & the exhaust valves in the "relaxed" position.
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+ [smiley=thumbup.gif] on Rob's valve lash procedure. I also pull the sparkle plugs as it's much easier to rotate the engine while adjusting and re-checking your work.
Monte
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My '79 R65 has just started to develop a metallic tap as well.
Most noticable at idle, between 3000 and 3500rpm and is definitely worse under load.
I've checked valve clearances and rocker free play. All good.
Plus it is the speed of just one valve, so I suspect maybe a lifter or camshaft.
Sounds like I'll have to pull the pots off over the weekend and have a look.
Bugger! I wanted to go riding........... :-/
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It's always a good idea to look at the lifters at least once in your ownership.
I've seen pictures like this a couple of time. But never from a R65, that I can recall.
This one is from a R100.
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I figured, it's not a big job, so I just went out and popped both pots off and had a look.
The lifters and cam both look nice. No pitting at all.
Now I'm wondering........ :-/
Anyone got any other suggestions before I start pulling things further down?
It's a very distinct metallic 'tap' at the same speed you would get a noisy valve.
Any words of wisdom gratefully received. ;)
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Your [exhaust] valves are not closing up on you between checks?
You are measuring the gap before adjusting them, and writing this info down with date & mileage, so you can see if there are any changes going on?
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The're not called 'tappets' for nothing ........
Other noise source could be timing chain due for replacement?
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The're not called 'tappets' for nothing ........
Other noise source could be timing chain due for replacement?
;D Yeah, but this is one single metallic tap and is definitely not normal.
I'll give it a really good look over and measure everything over the weekend and see what I come up with.
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Most noticable at idle, between 3000 and 3500rpm and is definitely worse under load.
Hard to see how valve noise would get worse under load as the valve train is only subject to the load of the valve springs and while cyclic should not change due to normal engine loading. Does that make sense or am I missing something ? I'd like to think for Tony's sake there was an alternative source of noise as a result of engine loading other than the big ends. On the other hand Tony is saying "at the same speed as valve noise" which means half engine speed and that would not sound like big ends.
While you have access to the con rods can you feel any play in the big ends?
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Most noticable at idle, between 3000 and 3500rpm and is definitely worse under load.
And it may be "detonation", "pre-ignition" or whatever term you choose for when the mixture is igniting before it should (by spark).
Try some fresh gasoline, perhaps a higher grade, and check the timing.
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Thanks for all the input, gentlemen.
Had a chat to BMw mechanic yesterday and he's uggested that a valve may be sticking. i.e. not returning to the closed position quickly enough.
Sounds reasonable as it does sound like a very load valve noise.
Anyway, I'll strip the whole thing. They're dead easy to work on, so I may as well give it a good once over and hope I don't miss anything! ;D
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A real remote possibility of the origin of the noise, I had a rocker arm needle bearing come apart .
The sheet metal flange of the bearing cracked out and allowed a few of the needles to escape through the gap in the support blocks that are at each end of the rocker arm .
All of the metal pieces ended up in the oil sump .
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If it needs new valve guides, only have this work done by AN EXPERIENCED airhead mechanic/machinist (that means both!).
If you have the work done by a motorcycle mechanic, or one that was not trained by the factory during the time these bikes were manufactured, I would give you 50/50 odds of them screwing them up.
Being in Australia, I don't know who to recommend. At the very least, send check with Munich Motorcycles in Perth.
If you do ship them, double-box them, or you may end up with a broken fin. (DAMHIK)
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If it needs new valve guides, only have this work done by AN EXPERIENCED airhead mechanic/machinist (that means both!).
If you have the work done by a motorcycle mechanic, or one that was not trained by the factory during the time these bikes were manufactured, I would give you 50/50 odds of them screwing them up.
Being in Australia, I don't know who to recommend. At the very least, send check with Munich Motorcycles in Perth.
If you do ship them, double-box them, or you may end up with a broken fin. (DAMHIK)
I've just had the guides done on my R65 LS along with a cylinder & head rebuild. The work was done by my local guy at Caringbah Motorcycles but he was quite open in saying that he had the guides done by Greg Ball Motorcycle Engineering in Kirrawee. (02) 9521 8470
He said he wouldn't consider using anyone else. It's in Sydney, by the way.
So far so good.
Maybe worth a call or chat after Rob's suggestion.
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[quote [/quote]
The work was done by my local guy at Caringbah Motorcycles but he was quite open in saying that he had the guides done by Greg Ball Motorcycle Engineering in Kirrawee. (02) 9521 8470
He said he wouldn't consider using anyone else. [/quote]
What a small world, i did work experience at Greg Ball Motorcycle Engineering when i did a trade course many many moons ago. Great to hear he is still around, i still remember how he showed me how to balance a crankshaft, he took pride in his work & a top bloke.
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The fellow (Bob Grauer) I had rebuild my heads a few years ago (http://www.pbase.com/tomfarr/valve_job) is a retired machinist and MAJOR airhead enthusiast (http://moragafalconers.org/bob_grauer_rig/index.htm).
It meant shipping them 2000 miles to California, but I was thrilled with the outcome.
He even repaired both stripped out center valve cover threads and plugged the fresh-air induction ports (U.S. models only?), no charge!
I would love to make it out to California some time just to meet Bob.
Hopefully, next winter I will have the funds to have him go through the heads on my latest engine.
I really hate that I tore up 1/2 of his beautiful work (http://www.pbase.com/tomfarr/image/105672258/large) in that meaningless crash of mine.
But my latest engine is new to me, coming from a non-BMW shop that was parting out the bike, with no history. And if they don't need any work, I'm confident he won't charge me much to take them apart and measure the bits.