Wear showing on Nikasil cylinders

[Festus]

Hello,
Hoping to get some advice. Going through the top end and on my left cylinder I can see that it has lifted off a bit on a small spot. And I'm out of $$. I have about 50k on the bike but as I'm getting older I don't ride as much, maybe 2 to 3k per year.

Anyone have experience with this type of wear?
Thanks
R80 1981. Saw one related post that mentioned that had a spot "lifted" and I think my bike has the early Nikasil.

[khittner1]

Google "nikasil replating". There are YouTube videos on nikasil cylinder maintenance, repair, and replating. Whether yours needs repair or replating is a threshold question that others are probably better equipped to answer, but a photo or two of what you're seeing would likely aid the discussion.

[Festus]

Thanks khittner1,
I'll post a pic when I get home.

From what I have been reading today (instead of working) it doesn't look good. I think I'd be more comfortable getting a replacement that had the piston already in it. Just a money situation.

Would you know if I need to replace both sides? I see a set of two. I was not the original owner of the bike but for the 15 or so years I have owned it I did do the maintenance.

Regards.

[khittner1]

Nikasil bores are usually quite durable, and it's unusual for there to be wear problems at the relatively low mileage you have. I understand that getting 200K+ miles out of them is not unusual if they're well-lubricated, so what you're seeing in your left jug sounds unusual. But if you've got a problem on one side, the other is certainly worth investigating. Check the IBMWR used parts listings for replacements. Rolland Robitaille is a fellow up in New Hampshire who regularly parts out airheads (full disclosure: I've bought a couple of parts from him that've been fine, though there are other sources), and he's listing bits from an R80RT presently.

[esman100]

I had an '81 R100 Nikasil cylinder with a few spots that had lifted and was told that BMW had adhesion issues on the earlier cylinders. I looked into replating and diamond honing, but it was more expensive than finding a good used one. I would look for '83 on up cylinders.

[Festus]

Hello,
Having trouble adding a pic. "exceeded quota". I'm a bit concerned because the one I bought on eBay
is shown as 0982/4 1275 from an 83, the one on my bike is 0918 5 1182 from an 81. Not able to find those numbers on the microfiche.

Mine is smooth black on the inside of the cylinder except for the spot that peeled up. The one that just arrived has a cross hatched pattern.

Thanks. I'll try again tomorrow with the picture now that I have reduced the size.

[SteveD]

You need to post your photo to an online storage site, then add the url to your message.

[Festus]

Pic of the cylinder with wear. Thanks for the upload advice, I had read that in the FAQ but also thought I could do it the other way as long as they were small in size.

http://www.flickr.com/photos/66182900@N03/

[Festus]

Pic of wear pattern on newly arrived '83 cylinder.

http://www.flickr.com/photos/66182900@N03/12229082663/

Thanks for any advice.

[khittner1]

No experience or advice, but just a question: Before you pulled your bike's cylinder(s), were you burning oil, or do you know what your compression was in the apparently-damaged jug(s)?