The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: jep on July 29, 2007, 10:43:14 AM
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Hello I'm pretty new here and so to start off thanks to this site and the contributors for the info regarding rebuilding my forks. I had to replace a bent fork brace, and with out this info I would still be out in the garage fiddling around. The tip about the tape around the socket on a long extension and the great pictures showing the "exploded view" of the forks are some of the info that helped me. For me it wouldn't be possible to keep this bike up without the tech help from this site. Also thanks to whoever keeps this site up and running.
Okay enough raving. THe bike is a '83. I have two R65's and of the two the "83 is the pristine one (the fork work was on an "80). The heads were done due to a worn valve keeper. It was chewing up the the valve stem and would of become real expensive. I had run out of adjustment one of the exhaust valves. The heads are back on the bike now after bead blasted, new guides, valves, and keepers. Labor and parts came to just over $700. Okay here's the problem: I have no clearance (I would say way way over 0.020)when the rockers are bolted down on the right exhaust valve. There isn't much adjustment left on the others as well. After discussion, with the wrench who did the valve job, he thinks that seats are needed and he is unable to do it. So is this what I need? If so where to go? I've been told that the new guides will have to be replaced with the new seats. Am I going to have a set of heads that are worth more than the bike? Thanks, jep
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THe bike is a '83. Okay here's the problem: I have no clearance (I would say way way over 0.020)when the rockers are bolted down on the right exhaust valve. There isn't much adjustment left on the others as well.
Could you explain this a little better? When the rockers are bolted down, the adjusting bolt is adjusted all the way anti-clockwise and you still have no clearance? OR is the adjustment bolt as far extended as possible and you still have more than 0.020 gap between valve stem and rocker?
I thought by '83, that BMW had solved the valve recession metallurgy problem. But it normally only affected the exhaust valves anyway, so if you say you have minimal adjustment on all the others, you might have another problem.
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First, we need to figure out what you have, the statement was made that I don't have any clearance, way, way over .020. I am assuming that you have excessive valve clearance that you can't adjust out, because the threaded adjusters on the rocker arm are at their limit. Are the adjusters threaded in all the way, or threaded out all the way ?
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Okay, pardon my dyslexia. I am unable to loosen the adjustment to get any clearance between the rocker and valve on the exhaust valve on the right side. The other valves have enough adjustment for 0.006 intake and 0.008 exhaust. But there isn't much to spare. jep
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How many miles on the bike? The normal problem with the early '80's R65 and their valve recession, is the valve face wears excessively, and the valve seat shows almost no wear at all. But with new valves installed that would eliminate the valves as being worn, your description would mean that yes the valve seats may very well be the problem. Only other possibility that I can think of, is the needle bearings that are pressed into the rocker arms, they are known to fail and start loosing the needles, leading to a sloppy rocker arm, and possible clearance issues.
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The bike has 67,406 miles on the odometer. I think that the needle bearings are okay. But how would I know? Excessive play something like that? Cost of new seats? jep [smiley=wall.gif]
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To check the rocker arms, it's probably best to remove them, and look at the ends of the rocker arms, the bearings have a thin sheetmetal shell, that cracks off and then the needles can come out through the gap in the support block that the rocker arm shaft goes through. I would think that the mechanic that replaced the valves, would have noticed any significant issues with the seats. Seeing as how you are a new member, how about a little background info on yourself ? Like, how long have you owned the bike, have you done all the maintenance on the bike yourself, etc.
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I live in Fairfield, WA (eastern part of the state). I have two R65's the second one purchased is the one ('83) with the valve issues. It was purchased for $1700 about two years ago. Previous owner had been a airhead mechanic at a dealership in California. The bike was immaculate. It had about 60,000 miles on it when I bought it. Beautiful in black with a nice Corbin seat. It looks like a black LS but it isn't. The motor was nice and strong it handled well. The maintenance so far has been done by me which has been tune ups, fluid changes, and some wiring upgrades. The bike is actually my wife's but I love to ride it. I first heard about this site from a couple of guys who rode R65"s at an airhead tech day in Portland, OR. jep
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jep, if you paid in the neighborhood of $700 for a valve job and didn't get new exhaust seats then you should NEVER give these guys any more of your business - and warn others off this shop as well! I had a set of R100 heads re-done about a year ago and with all new valves, guides, springs, and exhaust seats the bill was about $500 from a local indie Beemer wrench.
I'm not sure exactly how much it would cost to get just the seats replaced and the exhaust valves re-cut to the new seats but I'm sure everybody could chime in with their favorite machinists in your part of the country. You might find one who would do just the seats for you, maybe not...
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Jep, I agree with Justin and am sorry to say that if you paid that much and they didn't regrind and replace the seats
along with replacing the valves then they really did you a disservice - perhaps not intentionally, but still..
Whoever puts in new seats may end up putting in a new set of valves as a matter of course to make sure they will
be made to fit properly on the new seats. But, are you sure that the mechanic didn't replace the seats, and
perhaps not get that one correct ?
I haven't had to do this to my bike yet, but I suspect that it will be undergoing 'the treatment' at some point in the
coming few years. Rob Valdez also had good luck with getting his done a little while ago - he may offer some first hand
advice/experience. Sorry to hear that you are going through a bad experience on this..
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Okay, well jeez live and learn as they say :(. Sometime this week I'll call Bob's BMW and those guys that do heads that advertise in Airmail and ask about putting seats in the heads. I'll follow up with how much they are going to charge. jep
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Not sure why you would have to replace new valve guides just because you replace the seats. I can see having to recut the new seats to match the valves, but that isn't expensive. Valve guides only go in one way, and the only thing done to them is potentially ream them to fit the valve stem, but the alignment isn't altered.
I had favourable work from Motor Works in California - 619-233-8875. Note their price for everything you had done so far without new valves and keepers was $195.00. I needed new exhaust valves and seats and it came to around $300.00 about 3 years ago. Inlets were OK.
Another good machinist is http://www.brunos.us/ Bruno is in Canada but does mainly US work. Today with UPS and good post, you don't have to sweat about finding someone close to home.
Bob's does good work, but I find them one of the more expensive outfits out there.
I am not trying to be rude here, but you did rotate the engine one revolution after setting the left side and before working on the right, eh?
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Chris, the engine was rotated between setting the left and right side. The right intake had enough adjustment. Thanks for the info about Bruno. I'll check it out. About the guide replacement, I'm not sure where I heard it (wasn't here) but something about the geometry would be off if seats and guides weren't put in together. Makes sense to me that the guides only go in one way and that it shouldn't make any difference. jep
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If everything was done competently when replacing the guides then it should be a simple operation to cut the new seat to the guide. The pilot on the cutter/stone goes up into the guide so the cutter is centered. I agree with Chris that the guides and valves are probably OK but the machine shop may not want to take any chances but they may if they determine (to their satisfaction) the guide job was done properly. We live and learn and unfortunately some of the "learning experiences" cost a bit more than others.
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What year did BMW finally get the early '80's valve seat issue solved ? My '81 had the valves go bad by 45,000 miles, the seats looked like they were almost new, and the valve face was 2/3's gone.
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Bob, Our '81 R65 got the exhaust valves replaced at 100K so I guess engines vary. Also, we don't have the temperatures that you normally have to ride in down your way.
But I thought BMW had the problem solved by '83, but maybe it wasn't until '84, which was why I was wondering about jep and his '83.
Jep, Just make sure you get the valve seats (if required) replaced by someone experienced in BMW engines. Not just the average machine shop. I made a mistake years back having a local guy do my seats. I told him the recommended temperature the heads have to be heated too, but he said he never went that hot for all the Harley's he had worked on ( I should have run then :-[ ) Bottom line the head wasn't hot enough , so valve seat cocked going in and buggered up the head. Had to have special machine services to custom make a larger OD valve seat and custom machine a larger clean hole. My idea of saving a few dollars sure failed that time!
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From what I have read BMW finally got it right in the '85 and later engines.
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I also heard that it was '85 or '86 that the valve seats issue was resolved.
I've generally made it a point in the past to look for '86 model year bikes
to be certain.
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What year did BMW finally get the early '80's valve seat issue solved ? My '81 had the valves go bad by 45,000 miles, the seats looked like they were almost new, and the valve face was 2/3's gone.
Bob, according to Snowbum (also Bob) the year was around 1985:
http://bmwmotorcycletech.info/valves.htm
45,000? Oh no. I'm at a bit over 50,000. I wonder if my baby will let me pay off the freaking tranny rebuild and clutch parts before I start seeing valve deformation.