The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Matt Chapter on February 18, 2013, 09:05:50 PM
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Exhaust valve, left side. Video to follow, if I can capture it successfully and then post here...
The question is.. how bad is this? Can it be driven? Theoretically my R65 is my daily driver. Is this something that can happen naturally, or is it a result of loose spark plugs, or maladjustment? I just did the valves less than 100 miles ago.
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A bent spring?
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picture's worth a thousand words, so what's a video worth? This might be worth a beverage, even though it's only 2 seconds long..
Note the disturbing lack of parallel spirals, and the grotesque movement..
http://www.flickr.com/photos/77662887@N05/8488287428/
How hard is it to take apart the valve train to replace that puppy?
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should be public now...
It's hard to know who you want to see videos of your bent springs, if you catch my drift.
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You are not going to realy know until you remove the rocker arms. I have seen spring break or get weak. There is more of a chance of a valve getting bent than a spring bending to me.
Don
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I've only removed the valve collets and springs with the heads off. Normally you would use a valve spring compressor. I don't know if it can be done with the head still on, maybe with the piston at TDC and a couple of extra hands to compress the spring?
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IMHO, could be a broken spring. The parts gets one on the other but when compressed, slip and then it look bent.
Repair asap as it will ruin the valve guide and the valve. I had this on my R65...
To remove without removing the head you need something to hold the valve in place. Basically, a spark plug without it's innards, which are replaced by a sturdy steel rod pressing the valve in place while you compress the spring to remove the locking tappets.
But IMHO, you'd better remove the head and do a proper valve job. the valve stem may already have suffered from this and, as these stems are not the strong point of the bike you risk a broken valve, piston, cylinder.... soon....
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I can't see so well these days, there is something moving inside the outer coil. Maybe the spring is broken but is it also possible someone has fitted dual valve springs ?
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I can't see so well these days, there is something moving inside the outer coil. Maybe the spring is broken but is it also possible someone has fitted dual valve springs ?
It's a classic case of "which of these valve springs does not look like the other". The answer is that one!
If I have to take the head off to repair this, I'm in deep deep.. trouble. I guess I'd better have a look at my Clymer manual..
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Barry may be seeing things just fine... It does look, to me, as if there are dual springs fitted. Can you see if the other valve springs are duals? Something is going on within the outer spring coils...
"If I have to take the head off to repair this, I'm in deep deep.. trouble."
Even strain, Matt. Steady on. Most likely the head will need to be removed. It's not a difficult chore; the removal of the exhaust nut can be problematic should the threads be galled. If the nut refuses to turn smoothly, STOP! There's not much choice but to cut the nut off rather than destroy the threads on the head's exhaust stub.
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Most likely the head will need to be removed.
Arg.. so who wants to loan me a Tonquanockee cerimonial thingamajiger?
Ok, I'm making a shopping list. Is there anything else I should think about doing, like pushrod seals, if I take the head off? Should I just replace the valves no matter what, or inspect and then decide?
I drove it about 15 miles, max speed 65 mph in this state. :( (Assuming that this is the cause of my poor engine performance)
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First things first, Matt...
Do you have a rubber strap wrench? Cheap ones are at the Austin Harbor Freight.
Pushrod seals require removing the cylinder and piston as a unit; that's the easiest way, IMO. Also a full gasket and O-ring kit.
You may likely need a new head gasket for the head removal job.
New valves alone would not be a wise choice. Again, that's just my opinion. A complete head rebuild won't come cheap either. My advice is just what you said, "...or inspect and then decide."
Keep us posted and we can look over your shoulder as unpaid mechanic helpers. And that's the whole point of this forum, right?
Get on your bicycle or roll the cage but park your R65 for now.
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Heads remove easily-six nuts. Exhaust nut wrenches should be easy to borrow if you not own one. Check with a local Airhead. A valve spring compressor should also be easy to either borrow or rent from an auto parts store.
Push rods seals do not require removing piston or cylinder, only the head. Rotate engine to TDC compression stroke on cylinder in question. Remove exhaust nut and header, carb, valve cover, six head nuts, carefully slide rocker arms off in one piece-do not let the needles fall out of the bearings, pull push rods, remove head and then valve. Reverse going back together. Torque nuts in three stages up to about 25 ft lbs in sequence. Set the valves and ride.
New head gaskets are not that expensive. I would probably at least measure the other spring on that side while the head was off.
Doing this for the first time might take a couple of hours.
If in doubt check on a tech day locally. Airheads are the most helpful people I've ever met.
Bob
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... Push rods seals do not require removing piston or cylinder, only the head. Bob
Gonna have to throw the BS flag on you, BobW.
To remove the old, leaky tube seals requires lifting the cylinder up off the crankcase. To gain the service space required, there's no other way to withdraw the pushrod tubes from the crankcase and R&R the seals.
And after the cylinder base gasket and a few O-rings have been disturbed, they, too, must be replaced or you'll run the risk of new leaks and have to do the job all over again. By pulling the cylinder up and away from the piston -just enough to expose the wrist pin for removal- the cylinder/piston unit can be removed for the necessary gasket and O-ring replacements without disturbing the piston rings.
Matt, Here's Snowbum's tips on the seal replacement: http://bmwmotorcycletech.info/pushrodseals.htm
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Well, I swung by the $BMW$ shop today after work, ordered the spring, keeper, spring seat, and spring retainer. 47$. I guess it could be worse. Oh wait.. the parts won't be here for a week.
I've looked over snowbum's page, and my clymer manual... neither really covers removing the spring. I guess looking at the fiche that the spring retainer is threaded somehow and holding the whole thing together? I don't see anyway around removing the head, which means I should have ordered a head gasket.
I'm feeling a little better after looking over the procedure (and now that I have a boilermaker in progress..)
Can I disassemble now, and wait for the parts to arrive next week, or should I try to do it all at once?
Tool list: exhaust nut wrench. What else do I need? (other than more beer!)
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You don''t need to remove the head. You can either pack the cylinder (through spark hole) with small diameter nylon rope/cord or use compressed air to hold the valve closed. All that said it wouldn't be a whole lot harder to remove the head. If you do remove the head you should be prepared to cut off the exhaust nut and have a spare available...
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Do realize that the R65 exhaust nuts aren't the same as the rest of the airheads - they're smaller. So be sure to purchase the right one - especially if sourcing used.
I couldn't see the video - it just zipped right through really fast and I couldn't really see anything from it. So I can't comment on it at all.
As for removing the spring - you really need a valve spring compressor. You might find one cheap on ebay - or take the head to your friendly automotive shop around the corner and enlist their help. They probably wouldn't even charge you for doing it.
The spring is held in with a split ring retained by a large thick washer that the spring seats on. The spring compressor presses on the spring via the thick washer, thus forcing it away from the split retainer, which can then drop out and allow everything to fly apart.
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Valve spring compressors can be had for about $40 or $50 from auto parts stores. Chinese of course but a copy of the good old MECO ones that still sell for the same money if you can find one.
A good torque wrench will probaby be dearer than that, no point buying a cheap one of those!
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In my youth I always managed to compress valve springs using a lash up in a drill press. Think inverted "U" shaped steel strip with a bolt through the top that was held in the chuck. With suitable blocks of wood under the head to support the valve it worked well enough.
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In my youth I always managed to compress valve springs using a lash up in a drill press. Think inverted "U" shaped steel strip with a bolt through the top that was held in the chuck. With suitable blocks of wood under the head to support the valve it worked well enough.
There you go! Airheads improvise and save money. [smiley=thumbsup.gif]
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Ok, the video sucked. I'd like to blame my phone, my brother, and the poor lighting in my garage.
Here's a couple of photos...
good http://www.flickr.com/photos/77662887@N05/8492773866/in/photostream
bad http://www.flickr.com/photos/77662887@N05/8492773362/in/photostream/
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Hello !
To remove the spring you do not need any special compression tool. This tool is only needed to reassemble.
Remove the head from the bike and put it on the bench, piston side down on a rag (the purpose of the rag is to fill the combustion chamber and retain the valve).
Get a tube wrench bigger than the keepers diameter but smaller than the retainer. Get a middle size hammer.
Put the tube wrench on the retainer, and strike it with the hammer, a firm strike while retainer the wrench with one hand.
The strike will press the spring down freeing the keepers which will stay in the tube wrench.
If you hold the wrench with "some force", the spring and retainer won't jump.
It's easier to do than to explain.
This way, you will be able to check what's wrong, broken, and order the parts you need.
Definitely you need a new set of gaskets : push rod sealing cones, base O-ring, head gasket at least.
Then, depending on mileage and what you'll find during dismantling, a new set of rings, and maybe new connecting rod bearings..
If I was you, I'll put new valves and new valves guides because these break without any warning ruining the motor.
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Well guys I finally got around to tackling this, and I'm happy to report that it went pretty smoothly.
At first, I tried to remove the exhaust nut by myself. Once the bike started to lever up on the center stand, I enlisted some help to hold the bike down while I was pulling up. The nut came off without a hitch.
Then this evening I tore into it, took about 1.5 hours from "where the hell's my 15 mm socket" to "ooo, piston!" I actually ended up removing the cylinder and head as one unit. The cylinder bore looks clean, I can see some very faint scoring, might have been cross hatching at some point. The piston itself seems ok, some mild carbon deposits on the top. It seems like I may have gotten pretty lucky as far as big damage items. The head and cylinder are going in to a head guy, so hopefully I'll know more soon.
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<snip> At first, I tried to remove the exhaust nut by myself. Once the bike started to lever up on the center stand, I enlisted some help to hold the bike down while I was pulling up. The nut came off without a hitch. <snip> The cylinder bore looks clean, I can see some very faint scoring, might have been cross hatching at some point...
Your '84 motor should have the nikasil cylinders, so there shouldn't be any cross-hatch hone marks... unless a PO erred in working on these "no hone" nikasil bores.
Gasp! You evidently got very lucky if the exhaust nuts withstood that much removal effort without damaging the head's exhaust thread stub. Use some anti-sieze when going back together.
Hope your good fortune holds during the "Head Man's" work.
BTW, Matt... MotoGP's Honda Team Repsol is in Austin right now! Testing the track. Getting a jump on next month's GP race. Bengt Phorqs and I, plus our entourage, will be there.
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FWIW, I purchased an exhaust nut tool from Hendersen Precision - www.hendersenprecision.com for $35 bucks which worked just fine. Remember that if the old nuts don't start spinning freely after about 1/4 turn, cut them off and get new ones. Can't afford to damage the cylinder threads. Put some anti-seize on the threads when reassembling.
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Your '84 motor should have the nikasil cylinders, so there shouldn't be any cross-hatch hone marks... unless a PO erred in working on these "no hone" nikasil bores.
My hone marks were still visible at 60,000 miles or so. They are faint but not worn out. I did not hone even for my new rings, I just cleaned the bores up really well. I love nikasil... some day I will spring for some for my Triumph.
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Like Ed says, Nikasils are honed from the factory! It's suggested when re-ringing to lightly use a ball hone, but I'm not sure that's necessary.
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Hello !
My '82 Nickasil have eaten two sets of rings in around 100 000 miles.
Last time I opened up (last November), the glazing was starting to deteriorate at the top on one cylinder (the Guru said it could be used for another set of rings) but the honing marks at the base of the barrels were still visible. Pistons were quite spotless.. So the barrels are wonderful but the pistons are not bad either !
I did not hone the cylinders as I did not had access to the correct honing tool. Will see....
BTW, if you plan to clean the carbon deposit on the pistons, do this with nothing harder than a green Scotch Brite in order not to mar the tiny rings between the top ring and the end of the piston. These rings are here for a purpose.... And use light force... Patience is good when one see the price of the new piston....
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You need a decent torque wrench preferably one that isn't a high torque unit - when you reinstall the head bolts you'll have to torque them up gradually, in cross-cross pattern, first to ~15lbs, and then up to 24lb and no further. You need a tube of hylomar (now it is sold as permatex 25249 or something similar) too).
I've seen spring compressor tools, but maybe you can make do without one or borrow one from a buddy as it isn't the sort of thing one needs very often.
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Factory hone marks -even in high mileage, well maintained engines- may often be visible low in the cylinder bore as the piston rings do not get that far down the bore. Da Snowbum and other Airhead gurus are against doing any additional honing as the Nikasil plating is wee thin.
Clean the bores to where you wouldn't mind eating off them. Then lightly oil prior to reassembly. [smiley=thumbup.gif]
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Please excuse my introducing this thread to a tangent of sorts.
I am curious to know what to look for in determining the difference between the Nikasil coated cylinders of 1981 and on, and those made prior?
The following image link is of a Nikasil lined cylinder. If it wasn't labeled as such I am not sure I'd no the difference. However, looking at the damaged areas I can see the Nikasil coating as compared to the base metal and would describe it as a coating. Maybe that exposed area would be the look of a non-Nikasil coated cylinder?
It'd be a pleasure to see pictures showing the difference, but I'll settle for the awkwardness of the written wUrd.
http://www.stephenbottcher.net/BMW/R100ST/assembly/engine/2401.jpg
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Use a magnet, the '78-80 model year bikes have a cast iron liner in the cylinder .
The nikasil is a nickel plate on an aluminum cylinder, non magnetic .
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Factory hone marks -even in high mileage, well maintained engines- may often be visible low in the cylinder bore as the piston rings do not get that far down the bore.
Dunno if I have a "high mileage, well maintained engine"... in fact, local observation would tend to disagree, but yes, the marks I saw were viewed from the bottom of the bore.
BTW, Matt... MotoGP's Honda Team Repsol is in Austin right now!
This is a terrible time for me to be without a vehicle, and not just because the race track is at the other end of town. Now, that Repsol paint job.. nothing says "Arrest me! If you can catch me!" quite like it.
You need a tube of hylomar (now it is sold as permatex 25249 or something similar) too).
And what does one do with a tube of permatex? Is this the thread lubricant for the exhaust nut?
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"And what does one do with a tube of permatex? Is this the thread lubricant for the exhaust nut?", asks Matt.
This material is a sealer to be used where the cylinder mates to the crankcase. Prevents those nasty oil weeps. Snowbum also approves of Yamabond, available, well, you can guess where...
All that's required is a very thin smear of the sealer be applied to the crankcase joint. A dab about the size of a fingernail -yours or mine- may be spread with an cheap acid brush; the brush first being modified by trimming off half the length of the bristles. Hardware store. 0.29 cents.
DO NOT allow any sealer to get into the oil passageway. In fact, keep the sealer rather thin in the area said oil passage so the squeeze out will not block the passage. Important? Yep. Oil through this line provides lubricant to the valve train.
Permatex also makes an anti-seize compound. That's what you'll want to liberally apply to those exhaust threads. A copper-based anti-seize is my fav but it's becoming harder to find.
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Amazon sells several brands of copper anti-sieze - Permatex, Loc-Tite, CRC, etc.. About ten bucks for 8 ozs.
Wavy
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Amazon sells several brands of copper anti-sieze - Permatex, Loc-Tite, CRC, etc.. About ten bucks for 8 ozs. Wavy
Time to do some internet shopping. Thanks, Wavy D, for the tip.
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These are easy to find.
Go to a shop specializing into parts for factories or heavy trucks and construction works engines.
Ask them you want a grease with anti -seizure properties up to a 1000°Celsius and from a reputable manufacturer like Molykote or the like.
The salesman will give you 3 to 5 alternatives and sizes from small tubes to huge 200kg container....
Prices will be low if you buy the small tube ;)
Asking a local guy has two advantages :
- first you get your product right away.
- second the guy will give you very good advice because he will know exactly what he his selling... (the guy I met asked me what kind of metal I wanted to protect and when I told him it was to be put on a threaded part, he changed brand.... )
This is just my two cents, though....
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I talked to my local airhead guy yesterday. Apparently I rode the bike with the broken valve spring a bit too long.. Worn valve guide and cut valve stem. He's looking for a replacement valve and talking to a machinist. Should be another couple weeks and total roughly 300$.
When I dropped the LHS carb, I found the throttle cable was single strand instead of multi strand, so I'll be replacing that at the same time. And, since 4 carbs are 16 times as complicated as 2, I bought a morgan carbtune. Once I get the ol' bings reunited, I'm going to sync them.
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I have a replacement valve if you want it. It should be OEM. Not the best, but cheap and fast.
I also have springs and seats and collets.
I had a Nikasil engine that apparently saw some moisture before I got it. There were permanent damage to the cylinder bores (can't be repaired) and I had at least one rusty valve spring.
Valve guides can only be replaced with new, but I might be able to save you some money on the other stuff. I guess you don't need my spring compressor since you got a mechanic. ;)
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Thanks for the offer Rob. I let my guy know and he had already acquired one.
In exciting news, I got the head back today. Head cleaned, new valve, ground, etc etc. I also needed a new left hand throttle cable, and I got a new head gasket, new cylinder base o ring. 300 USD, although we did a part swap on the valve spring and collets. (I ordered the spring first, then called my mechanic, so I gave the parts I ordered to him.) Pictures to follow this evening perhaps.
The problem is, since the R65 is so rare, he didn't have the pushrod seals in stock. I'm about to call the local $dealer$, but I doubt they'll have them stocked either..
Who's got a line on a quick push rod seal supplier?
<edit: photos!>
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Ffarm8.staticflickr.com%2F7285%2F8743190350_d60a033cc0.jpg&hash=1d369642ee3f41f936c35749fb4057a49138890e)
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Ffarm8.staticflickr.com%2F7286%2F8742072391_16a3d6a19c.jpg&hash=4b2f153ec49e70c4b9a8a6c19518cf7ed9890e7c)
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Ffarm8.staticflickr.com%2F7282%2F8743185716_6371f78de0.jpg&hash=a666ca62b8473648822fab7a3084b291316815c6)
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Well guys it's done.
I tackled it yesterday evening, started after 630 or so, went out for a test drive at 1030. Took a couple long hammers (http://redhook.com/beers/ipa/) to get the job done.
The toughest parts were hand compressing the rings, getting the pushrod seals to line up (they didn't really get where they need to be until I installed the head nuts), and the exhaust clamp on the front crossover. Who knew the screws only went into the clamp one way??
Rode it into work this morning so life is good. 8-)
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Congrats. Hope you enjoy the rest of the summer - when it arrives.
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