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bstratton
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Hi all

New member and brand new first time owner of a 71' R60/5 (or any BMW motorcycle).

Bike has been well used and properly cared for but looks as original as it is. Nicks and dings and all.

Bike runs really nicely. I ride it regularly with no issues. All I have done is top off fluids, remove and clean carbs, replace all fuel line, clean and gap plugs, adjust valves, adjust clutch cable, and change the rotted front tire. It passed inspection without problems.

The only issue is the left cylinder will smoke at stop lights after it warms up. Smoke is blue, definitely oil. Doesn't smoke while driving (or not enough to see).

with 73k miles on it I am thinking I may be looking at rings and valve guide seals. I would prefer not to hone the cylinders to next size and replace pistons. I am hoping to just remove the glaze and any scratches on the cylinder walls and put new rings in it and replace valve guide seals. Hoping not to have to involve a machine shop but will if I need to. PO has owned the bike since late 80s and put almost all the miles on it. He says he has not done any work on the cylinders other than to put over-sized gaskets in the bottom of the cylinders to correct a pinging issue due to low octane fuel. Apparently it lowers the compression a bit.

Any thoughts from those who have been there done that would be appreciated.

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Bstratton
1971 R60/5
1965 R50/2 (project)
MA

schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
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Welcome to the forum! Before

Welcome to the forum! Before you tear into things, I would suggest performing a compression test and even better a leakdown test. That will let you know what the problem is. Another way to determine where the issue might be is to see under what situations it smokes. Does it smoke on acceleration? Probably rings. If you come down a hill and quickly close the throttle and it smokes, that probably indicates valve guides (no valve seals on these heads...just guides).

If you go down that path, I wouldn't arbitrarily say now that you won't be doing oversize. I think you need to get the info from the tests and then measure precisely the status of the bore. You might find you're too far out of spec to not consider a 1st over.

But if you want to do the easy thing first off and see what happens, maybe that's a plan. Me, I hate to do all that work getting in there only to find that I'll have to do it again in 20-30K miles.

I read where you said it smokes after it warms up. If you had said it smokes right after engine start but then goes away, I would have said that is due to parking it on the sidestand. Oil can drain past the rings into the chamber when it is leaned over. Parking on the centerstand or leaning to the right for a number of seconds after shutting it off can minimize this.

The 600 cc bikes were prone to pinging...my Dad had a '75 R60/6 and we could never totally get rid of the pinging. It's due to the high compression ratio and the camshaft/valve timing. Base gaskets was a way to go. But with the advent of electronic ignitions, such as the Boyer, the advance curve can be detuned thus providing some relief. With proper tuning and control of the advance curve, it might be possible to run without the base gasket. Note that there may be a ridge at the top of the bore that would need to be removed if one were to go down this route. If the ridge wasn't removed, the first time the rings went to the top, they could break if they hit the ridge.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

bstratton
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Thanks for the insight,

Thanks for the insight, Kurt.

Interesting stuff. It actually did smoke at start and then stop and I am glad to hear my theory might be right. I use the center stand now and that has pretty much stopped.

The smoking does not occur on acceleration - ever. It always happens when I come to a stop after downshifting and once it starts it keeps up until I drive away. It really gets pretty bad sometimes. When I take off it smokes for a few seconds and then clears up.

I can do a compression test. I have the gauge. I leakdown test is something I have not done so I will have to research it. I am thinking now that I might get away with just valve guides (which I will need to research, too). I do have the original owners manual, which gets into a surprising amount of service. Unless I am mistaken that may mean just removal of the head and a valve job. I suppose that I should do both if I do one

It would be very valuable to have a local resource for service on this bike in case I get too far outside my comfort zone if anyone has knowledge of someone in Eastern Massachusetts, RI or Southern New Hampshire, that would be much appreciated. Someone with a machine shop that has experience with these bikes would be ideal.

Burt

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Bstratton
1971 R60/5
1965 R50/2 (project)
MA

schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
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Burt -Are you familiar with

Burt -

Are you familiar with Max BMW? I understand they are top notch, especially Rusty in parts. He knows Airheads very well. I think he's in the Brookfield CT store.

IMO a valve job should be done by someone who knows Airhead equipment. I suppose it's "just heads" but I think there's a knowledge level that needs to be there. I recently had my heads reworked on my /7...I sent them off to Ted Porter at the Beemershop in California. There are good people on the east coast, the one being Tom Cutter at Rubber Chicken Racing Garage in Yardley, PA. Max BMW is probably worth considering as well.

This list was compiled a while back but gives some idea of Airhead friendly shops around the country:

http://micapeak.com/bmw/Airhead-Shops.html

YMMV.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

khittner
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Also, you might want to check

Also, you might want to check the dealer and independent shops listed on the IBMWR website IBMWR Independent Shop List. Chris, at Affordable BMW Service has done a lot of YouTube videos on airhead services, and appears to be knowledgeable, even if his manner may seem a tad salty to more sensitive sorts. Others will likely chime in with their preferred referral sources.

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Konrad

schrader7032
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San Antonio, TX
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Konrad - How current is that

Konrad -

How current is that list from IBMWR? I don't see a date listed on it, but I had thought that was a pretty old list, like maybe back to 2000. It would be good to know how current it is.

Thanks...

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

bstratton
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Spoke to one of the techs at

Spoke to one of the techs at MAX BMW in CT.

They farm out their machine work. They were more interested in having me bring in the bike so they could tear it down and go through the cylinders and heads and do anything that needed to be done and send the heads out for re-work and valve job. They estimated $1,300.00 unless they found cylinder or piston work that needed to be done.

I'd like to do much of this work myself and would rather find a good machine shop experienced with airheads. I'll keep looking.

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Bstratton
1971 R60/5
1965 R50/2 (project)
MA

schrader7032
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VBMWMO #7032
San Antonio, TX
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You can still do the work and

You can still do the work and ship it anywhere in the country. I had my /7 heads redone by Ted Porter in California. Tom Cutter is in PA. I believe Ted does his own heads while Tom prefers to send them out. Memphis Motorwerks also does this work. Bore-Tech does work, I suspect mostly on cylinders...they can put a carbide treatment on the walls and have it matched up to whatever pistons you want to use.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

khittner
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Independent Shop List

schrader7032 wrote:

Konrad -

How current is that list from IBMWR? I don't see a date listed on it, but I had thought that was a pretty old list, like maybe back to 2000. It would be good to know how current it is.

Sorry that I missed your post/query, Kurt. Yeah, I don't know how current the IBMWR's independent shop list is. The "Experience Counts" section (dealer/vendor ratings) is explicitly noted to be un-maintained since '10, so perhaps the absence of such a caveat might mean that independent shops list hasn't been abandoned?

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Konrad

SteveL
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Do the leak-down test

Do the leak down test. I had low-normal compression (barely made it to 100 after 6 full cranks). Leak-down test pointed to rings. When I pulled the jugs I found some scoring in the cylinders. With the heads off I also puddled brake cleaner on the valves and nothing came through. It’s the rings.

You can get a surprisingly decent leak-down tester from Harbor Freight for $40. They call it a “Cylinder Leakage Tester”, item # 94190. It was the best money I ever spent. Pick a time when your work area is fairly quiet. Pull the plugs and the intake tubes. Unscrew the dipstick. Get the cylinder on TDC. Attach the leak-down gizmo to the cylinder and open it’s “regulator” valve. If it’s rings, you’ll hear the air escaping into the crankcase. It’s pretty obvious if you listen near the oil fill. If valves, you’ll hear through the carb intake or at the end of the muffler. Trick is to be sure you are on TDC. If either valve is slightly open it will sound like the valves are leaking.

I’m betting your rings are shot. But don’t buy the rings until you pull the cylinders. Mine were scored a little so simple deglazing may not do the trick. (It’s still a work in progress. I’m waiting to borrow a set of snap gauges.) I have $120 in rings that may be useless to me if I have to go one over.

bstratton
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Going for it

Just took my last ride for this winter. Weather has been unusually warm this year. I'll be taking the bike inside now and will tear it down to take a look. The thing that is most interesting is that as soon as the temperature went down a bit the bike ran perfectly. No hint of smoke ever under any circumstances. I will still tear it down because I don't want to deal with the smokey left cylinder when summer comes along and the temps get into the 80s - 90s. Any obvious scoring on either cylinder will be dealt with. Heads will be sent out for valve jobs. I did go to MAXBMW in NH and met Rusty. Great guy. I bought new plug wires and front fork boots from him. I will talk to them about any machine work I want done. Not sure if they farm it out but if they do no big deal. I'll drop a note to tell you all what I find. Hate to take a bike that runs great apart but I don't think I have a choice. Since the exhaust will be off I will probably replace the front part as it is (I think) beyond reasonable repair. It's just rusty as hell. Dented, too. Actually so are the mufflers. Maybe a whole new exhaust..... I have a set of hard saddle bags that need some TLC so what the hell. Tank is going to a professional for paint and pinstripe. It's pretty beat up and has been (badly) painted in the past. Pinstripe is gone. I just don't have that kind of talent. i'll glue on new pads. I'll soda blast the motor and hubs to clean her up. With any luck next year she'll be a looker. Also may look into the electronic ignition. Maybe I can put it back together without base cylinder gaskets.

Any thoughts from those of you who have been here done that would be welcomed..

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Bstratton
1971 R60/5
1965 R50/2 (project)
MA

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