The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: CrawlingForward on August 26, 2016, 02:45:20 PM
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EDIT:
It's on youtube, but I'm too new to post videos or links, so just add watch?v=j3ehebmDjdo
after the youtube/ URL
I'm *really* hoping it's an exhaust leak, but I'm fearing the worst.
It started out gradually at first, as in wasn't sure if there was a noise or not while wearing a helmet, but on my ride home from work today it got louder pretty suddenly, like over 10 minutes.
Still runs and idles well and has had no trouble starting recently.
Thoughts?
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Oh, shoot.
Didn't realize I had not posted on here yet.
'84 R65 with 20-50k miles (odometer was broken for a bit). No previous issues except some light oil leaks, but I've been diligent on keeping track of levels.
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Hmmm, I wonder if it will let me post links if I keep replying to myself....
https://www.youtube.com/watch?v=j3ehebmDjdo
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Kinda hard to tell the source from the brief video, but it doesn't sound like a happy sound, though these engines can be rather noisy of their own accord at certain times.. Could be a number of things, from badly adjusted valve lash, broken valve spring, part of a valve seat broken off, timing chain tensioner broken, or flying squirrels. Exhaust leaks can sound odd, too, as there is a split ring that is compressed against the exhaust port of the head under the spider nut, and it that is broken it could conceivable rattle with the piston strokes. At least the engine seemed to still fire on that side, so probably not a totally nonfunctional valve train.
First thing I'd check ('cause it is the easiest, and the sound could be related to the valve train) is to get the bike on the centerstand in the garage and remove the valve cover on that left cylinder, and inspect the rockers, valve stems, valve lash, springs.
Then, take the spark plugs out of both cylinders (leave the valve cover off - you can also remove the right side one to do comparisons). Remote the round rubber plug/bung from the leftside engine case so you can see the flywheel and timing markings. Use the clutch and get the gearbox into 3rd gear - you may have to do a bit of rear wheel turning to get the gearbox into 2nd, then 3rd gear - 3rd is much easier to turn the engine round. After this is accomplished, use the rear wheel to rotate until you see a small "T" (or S or Z) in the engine case hole... if you see a Z then the "T" will be coming up soon after in the rotation from the top->bottom in the hole. You want to get the "T" (there is a small line just above it) basically centered in the hole for valve clearance checks. When the "T" is in this position, both cylinders are at TopDeadCenter, but one side will be on the compression stroke (both valves closed and the pushrods should have no pressure on them, so you can rotate the pushrod ends with your fingers, and also observe a small wiggle-able gap between the top of the valve stems and the rockers that press on them. The other cylinder will be on exhaust stroke and will have pressure on the pushrods and valve open. You want to check for the proper clearance on the side at compression stroke. Rotating the wheel until the T comes round again will have the cylinder's states reversed, and you can check clearance on the other side for comparison.
You can also shine a light inside the cylinders' spark plug holes to see if you see any loose metal in the cylinder as the pistons move in & out.
Have you done this sort of work before? It isn't too difficult, just take your time and be very methodical and you won't do any harm/damage.
Report back what you see/take pictures.
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Thank you, this is exactly what I need to start troubleshooting!
I've replaced non-interference timing chains on the Jeep before, but despite my years and years of working on Jeeps and motorcycles, I've never actually had any give me engine trouble, strangely. So I'm comfortable with engines, but have surprisingly little hands-on experience.
I definitely have a visible exhaust leak with soot buildup on that side and I've had a previous Yamaha Radian with a similar noise that had I assumed was a valve problem until I noticed a missing header bolt. New bolt and the noise was gone. I have a habit of going doom-and-gloom for items that end up as minor issues, so I'm trying not to do that until I've confirmed the issue this time.
Other item of note: I previously had a valve seat leak that put gas in the oil without me knowing, and only got down the street before the gas in the oil warmed up enough to richen the mixture, smoke, and stall the bike. Walked it home, changed the oil, and it was right as rain. (Luckily knew what it was right away because I had had the same issue on a previous bike. Petcock shutoffs are my friend now). I put regular motor oil of the correct weight in, figuring I'd change it with a higher-zince oil in a couple hundred miles just to clear out the system. Only put like 15 miles on the new oil before the noise started, though, so low-zinc I assume is not the issue. It's not symptoms normally associated with rich condition or thin oil, so I'm assuming the flooding is coincidental timing, but I'm keeping it in the back of my mind.
I ordered a steel exhaust nut tool so I can pull it off and inspect it (even if unrelated, the exhaust leak needs to be fixed.).
I'm traveling the next couple weeks, so I apologize that it might be a bit before I can give an update, but I'll get there!
By the way, Barnstead, no way! I used to work at T.L. Storer after college. Used to hang out at the bar formerly-known-as-Gizzy's on Thursday nights all the time.
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Do yourself a huge favour and buy some penetrating oil NOW and dribble some on the exposed exhaust threads every time you walk past the bike, or alternatively make an excuse to walk past at least once per day (preferably more often).
When you decide to remove the nuts by all means apply whatever pressure is needed to start the nuts moving, but if they do not immediately free up, or worse if they free up and then become tight, STOP and break out your hacksaw or iuf you own a Dremel or like tool, a cutting disk and cut the nuts off.
A pair of new exhaust nuts will cost you hundreds of dollars less than having new thread put on the heads.
I'll leave you to read Snowbum on the topic of exhaust nuts and leave you with one simply mantra - "new nuts are cheaper than any repair alternative".
I have an airhead friend who years ago managed to stuff the head threads on his R100 twice in as many years - he now applies very light pressure to the nuts and if they do not move, cuts them off then and there. He is a bit gun-shy though.
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Do yourself a huge favour and buy some penetrating oil NOW and dribble some on the exposed exhaust threads every time you walk past the bike, or alternatively make an excuse to walk past at least once per day (preferably more often).
Good call, thank you! I'm going to go start right now.
I got time on my side, so I'll definitely apply that. I've also learned over the years that a liberal application of MAPP gas can also do wonders in conjunction!
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Yes - if you haven't taken those nuts off before - you DEFINITELY want to mind the advice Tony provided - this is one of those bug-a-bears common to BMW airheads. Acetone and ATF work great too, but the volatility and obnoxiousness of the fumes is not to be overlooked. It is an annual ritual that I loosen the nuts, scrub off the dried up anti-seize, and put on a new coat every year, whether I have any other reason to remove the nuts or nut.
Yes, the scout camp (and several other summer camps) are still in full operation. A few years ago I ended up "rescuing" a pack of cub scouts and their leaders on a nearby mountain, who had hiked in for a few miles and gotten lost trying to find their trail back. The youngest ones didn't want to walk so far anymore, and I ended up taking the pack out to where I had parked my truck, left one leader with them and brought the others back to camp to get their vehicles to bring the whole gang back. They offered me hot dogs and beans for dinner, but I took a rain check.
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Still waiting on the tool, but I took a closer look at the nut while doing my twice-daily PB Blasting, and the left side is unscrewed over two full threads more than the right.
Really still crossing my fingers for just an exhaust leak.
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... I took a closer look at the nut while doing my twice-daily PB Blasting, and the left side is unscrewed over two full threads more than the right.
That could be a possibility.
Locate a length of fairly large diameter flexible tubing. Start the engine. One end of the tubing next to your good ear and the other end sniffing around the butterfly nut threads. Compare with the other side. You may find your noise.
Check a parts fiche for your '84 model. There should be at least one thick, split ring "washer" with a tapered surface on a side, flat on the other. Some Airheads have two such critters -as does my R100S. They must be fit correctly. If the butterfly nut has an interior beveled area at the header pipe opening, the split ring bevel should match up. Flat side to exhaust port.
Be sure to check both sides. A PO may have messed up with a single ring on one side and two rings opposite. Stranger things have happened.
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Good news! The nut came off with no damage to the threads!!!!
(https://scontent.cdninstagram.com/t51.2885-15/e35/14310638_1686076295045418_925136326_n.jpg)
I've been PB Blasting it once or twice a day for the last couple weeks and finally got the tool in the mail a few days ago. I was extremely discouraged at first, as with a 3/8" ratchet it was not budging (though the bike was tipping). Figured I'd have to hit it with a torch.
Grabbed the breaker bar, though, and gave it a try. After a *lot* of force to initially break it free, it spun off pretty much by hand, so the PB Blasting appears to have paid off!
Checking the diagram off Bike Bandit:
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fcdn1.bikebandit-images.com%2Fschematics%2Fschematics%2Fbmw%2Fbmw002%2Fbmw-05-05-10307.gif&hash=f0111635b926accf47275c5b2a16bc56c67976b1)
It looks like the setup on my exhaust is correct and complete, so hopefully just cleaning it, anti-seizing it, and threading it back on should be sufficient to correct my noise.
*Fingers crossed*! :-/
Any insights from the image above?
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It does kinda look like alot of soot/black stuff has been blowing through there - mine do not look like that. Maybe the header pipe isn't fully seated, or might have a crack/split in it?
First, I agree - just try to clean things up (use anti-seize on exhaust port threads) and snug it back together and see what happens...
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Your observation in the original post of an increase in noise over a 10 minute period (was that from cold?) could be as the engine gets up to temperature, I would pull the head checking valves and seats you have already done the hard bit getting the exhaust off.
Lou
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Someone please correct me if I'm in error, but is the split ring on backwards?
Enlarging the photo, I see a bevel inside the threaded exhaust stub. If's that correct, the beveled portion of the split ring should mate with the exhaust stub's bevel. The flat portion of the ring will mate with a flat inside the butterfly nut.
Swapping the ring around will permit -maybe- the butterfly nut screwing down further and leaving fewer threads visible.
Either way, clean that junction properly and use an anti-seize compound when reassembling. I prefer a copper-based anti-seize available at most FLAPS.
Now, what about that split ring bevel position? Anybody?
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If I am seeing the picture correctly, I think that the ring is the right way 'round. In the contemporary R80/R100 bikes with (2) exhaust sealing rings, you put the two rings' tapered sides together, with a flat side against the exhaust port on the head and a flat side against the spider nut. The (2) tapered edges on the inside position causes the split ring to get pinched "closed" when screwing the spider nut down.
Now on the R45/R65 (pre 1986) there is only 1 split ring, and the spider nuts are specific to those bikes.
The cylinder head's exhaust port is still flat on the outside, and I believe the spider nuts inner surface is tapered to matchup with the taper on the split ring. So, I believe that exhaust ring's tapered end goes outward toward the spider nut.
But, before the parts in t he above picture get assembled, they really need cleaning. Maybe getting a replacement ring wouldn't be a bad idea either?
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Hi there Crawling, welcome!
Now you maybe don't want to hear what I've got to say, so you may fairly take it with a grain of salt.... From your video I think I can recognise you concern, that really metallic valve chatter? Especially noticeable on the start up video. In my small experience of these machines (almost 3 yrs) I've managed to thrash mine to death and repair it to running more smoothly than when I bought it, with awesome help from this asylum!, and at least a Clymer repair manual.
The running chatter of your machine sounds very much like mine after buying her with high km (150,000km on purchase) and riding it 6000+ rpm on tours over more than two years. I eventually popped an exhaust valve seat out, that was the original and by then had done 173K km. The valve seat was worn thin as a streaker running to be free.
So I got my heads reconditioned, bought new valves and on reinstalling them I fixed another noise problem that you have, the rocker arms have too much play on their shafts, causing another metallic 'hit' noise. Have you adjusted your valve clearances yet? You can measure your rocker arm axial movement ('up and down') when you do this and it's the play I mentioned. It's part of the normal tune up, which should be done at least once a year. This play can be reduced by various means.
Hopefully I'm not getting off topic from the rest of your guy's replies but I just watched your video Crawling and it's so familiar to me!
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mmmm well spotted Monte, Motobins part # 88715 shows the ring only chamfered on one side that could well be part of the problem but the noise does sound "metallic".
Lou
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mmmm well spotted Monte, Motobins part # 88715 shows the ring only chamfered on one side that could well be part of the problem but the noise does sound "metallic".
Lou
I've become overly cautious with buying used motorcycles. First time I removed the headers on the R100S, which utilizes two rings, they were installed backass backwards which prevented the header pipe into head junction from sealing correctly. A good cleaning and inspection will tell.
As to the noise, quien sabe? :-/
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My post above was done after watching a couple of extra videos that started automatically after watching yours, Crawling. I thought they were all related but didn't take notice of the bike colour etc, I'd had a couple of drinks! There is a video posted by gsx1400aus or similar, with a black R65 which also runs pretty similarly to yours at idle, and I have to say, much like mine when hot. I accepted it as the airhead sound but you can lessen the tappet noise by reducing the rocker arm axial play, without getting into the 'can of worms' area of inspecting valves and valve seats. Nmahf was spot on in his post describing how to set the valve clearances, this is the best starting point and does not involve dismantling the cylinder (which is actually pretty easy to take apart but you need to buy a gasket kit to put it back together properly).
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CrawlingFoward, a compression test will give you a good idea about the condition of your valve gear and cylinder rings. A good service station or hire place will have a gauge for hire without the need for buying one. On the cylinder that eventually had a valve seat fail, my first compression test showed a very poor reading, 67 psi, two years before I eventually busted it.
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CrawlingFoward, a compression test will give you a good idea about the condition of your valve gear and cylinder rings. A good service station or hire place will have a gauge for hire without the need for buying one. On the cylinder that eventually had a valve seat fail, my first compression test showed a very poor reading, 67 psi, two years before I eventually busted it.
If possible, do both the compression test and a leak down test.
For the compression test, the engine needs to crank a few cycles to get a gauge reading.
With a leak down test, you'll be able to pull the carbs and exhaust headers and "listen" at intake and exhaust ports. Any whistling, squeaking, hissing... may indicate there's a bad valve and/or seat within that head.
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With a leak down test, you'll be able to pull the carbs and exhaust headers and "listen" at intake and exhaust ports. Any whistling, squeaking, hissing... may indicate there's a bad valve and/or seat within that head.
Hope I'm not hijacking the post too much but now ahh've been wondering how to do a leak down test, thanks Monte! Is that done by cranking the engine or with an air compressor feeding in air through the spark plug hole? It sounds like an easy job for google, unless any special anomalies.
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With a leak down test, you'll be able to pull the carbs and exhaust headers and "listen" at intake and exhaust ports. Any whistling, squeaking, hissing... may indicate there's a bad valve and/or seat within that head.
Hope I'm not hijacking the post too much but now ahh've been wondering how to do a leak down test, thanks Monte! Is that done by cranking the engine or with an air compressor feeding in air through the spark plug hole? It sounds like an easy job for google, unless any special anomalies.
Leak down testing uses an adapter in place of the spark plug. With engine ar TDC -ie: both valves closed- the cylinder is pressurized and a gauge is monitored. Someone may have info on how much pressure for the Airhead cylinder and either rate or time for X- minutes. Rapid loss of pressure could point to either a valve or even a broken piston ring/s. Either way, it would be time to remove the head/s for inspection and check for a broken piston ring or worn cylinder bore.
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Happy to report she's back together and running happy!
Sorry for the delay. It's often a while before I get a chance to get out to the garage.
I did, in fact, have an exhaust leak, but that wasn't the issue.
Don't worry, I did clean up the exhaust component before screwing it back together with copper anti-seize. It was pretty gunked up, to the point where it couldn't fully seat (hence the leak).
(https://scontent.cdninstagram.com/t51.2885-15/e35/14276571_286177211768379_5443166423935352832_n.jpg)
After putting it back together, the noise was unchanged, so I opened up the valve cover and saw this:
(https://scontent.cdninstagram.com/t51.2885-15/e35/14310636_1221828691210460_635760145988583424_n.jpg)
Ha ha, yup. That might be the issue.
The exhaust valve lash adjuster locknut had completely backed off and had self-adjusted to around an 1/8" gap. I had checked them a few months ago and they were in spec, so I didn't touch them. Clearly I should have checked that they were snugged down. Lesson learned!
Luckily, better loose than tight and I only ran it for about 5 minutes, so no damage was done and after a quick adjustment, all is well again.
Thanks for all the help!
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p.s. Is there a way to get email notifications? I totally missed the second page of replies, sorry.
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Email notifications? Just like our Airhead motorcycles, it's pretty basic here on R65dotorg. 8-)
So how did you miss page two?
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Just below the window where you would type text for a posting, there is a selection for being notified of replies to this thread .
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Just below the window where you would type text for a posting, there is a selection for being notified of replies to this thread .
Still have to log on. Close but not exactly what tunnel guy wishes for. :-?