nikasil cylinders

Hello , new at this, have a 1980 r1oort and it's using oil. Was told that the piston rings are probably worn because of the Nikisil cylinders BMW used at that time.
Bike has around 90,000 miles on it.
Anyone have the same problem?
Thanks.

Unless the original cylinders were changed, 1981 models were the first ones to get Nikasil lined cylinders. But at 90K miles, they could just be worn out. Mine were out of spec at 100K miles.

4738 said:

Hello , new at this, have a 1980 r1oort and it's using oil. Was told that the piston rings are probably worn because of the Nikisil cylinders BMW used at that time.
Bike has around 90,000 miles on it.
Anyone have the same problem?
Thanks.

Click to expand...

No one in all likelihood.

Nikasil cylinders are an order of magnitude improvement over the iron-lined cylinders on earlier Airheads. In the 25+ years I ran my '84 R100RS there was in reality never a need to look at the dipstick between oil changes as there was always zero oil consumption. That's something that can't be said about the previous bikes. (Had one too) The only downside to Nikasil cylinders is that they shed a lot of heat ... by design, as they are what made the G/S and GS possible. It was early BMW V8s in cars that had Nikasil problems, never the bikes. As Kurt posted, you probably don't have Nikasil cylinders in any event.

It is unlikely your bike will need new cylinders. The rings are designed to wear in a Nikasil bore not the cylinder bore itself. These Nikasil coated aluminum cylinders can be damaged and they can be recoated. At 90K if that mileage is correct your engine should need rings (pistons checked carefully) and would benefit from a valve job. But those service items require tests and inspection to be sure.

120K miles

At 120K miles my 84 R80RT needed new pistons and cylinders, the rings wore out and the pistons started slapping in the cylinders. For cost saving (1/4 the cost of new BMW cylinders at the time) I had them bored out and had cast iron sleeves pressed in. I am now at 201000 miles and do not burn oil nor have any issues with the cast iron.

So from my perspective, nikasil did not last any longer than the cast iron.

By the way before someone says well did you do XY and Z to maintain the bike, YES I did and still do. I DID ride fast and hard when I was 30 years younger.

I seem to recall there was some discussion in either the MOA forum or the Airheads forum or one of the BMW noted experts that the first years of nikasil was not all that it was cracked up to be. I am not going to look for the articles as I have my own feeling about nikasil. St.

You likely don’t have Nikasil cylinders; you have iron liners pressed into aluminum jugs, and you may be ready for valve guides, or a re-bore—or new cylinders. Get in touch with an expert airhead wrench and get/take their recommendations. I seem to recall that re-boring the iron-lined 1000cc jugs is more problematic than with the smaller displacement engines. It could be time for a Siebenrock kit.

khittner said:

I seem to recall that re-boring the iron-lined 1000cc jugs is more problematic than with the smaller displacement engines. It could be time for a Siebenrock kit.

Click to expand...

Exactly what I had heard. Not wanting to try a rebore (and having to go to plan B relatively quickly down the road), checking with BMW on the price of all new OEM parts, I went with a Siebenrock kit. It's basically the aftermarket version of the BMW Nikasil setup except that parts are lighter and should dissipate heat better than stock. The cylinders were about 30 oz lighter and the pistons and wrist pins were each about 1-2 oz lighter.

Cylinders

In regard to not having nikasil, cylinders, if it is me you are talking about, I am sorry, I DID have nikasil cylinders on my bike from the factory. They lasted 120K and then started piston slapping. They Were bored out or what ever at a machine shop and a iron sleeve was put in. That has lasted now to my current miles of 200K, with no problem, no oil burn.

At the time the nikasil cylinders went bad, there was only one option to replace, that was BMW. I had the work done for 1/4 of the cost and still have a fine running bike.

Also as I stated, there are articles in regard to the first years of nikasil not being as good as claimed. Again, I don't have the time nor inclination to look them up. Nor do I feel like digging through Snow bum's writings.

Sibenrock has given a cost effective choice to replace with nikasil if you want to that in the past BMW did not offer. I may have taken advantage of this had it existed then.

So, as I have stated, I am not impressed with nikasil. IN MY CASE, it did not last forever, and it was too expensive to replace. If someone else had better luck with it good for them. Perhaps they did not ride like I did or they got better rings, who knows?

I love my BMW airheads but I also know their shortcomings and history. St.

STEVENRANKIN said:

In regard to not having nikasil, cylinders, if it is me you are talking about, I am sorry, I DID have nikasil cylinders on my bike from the factory. They lasted 120K and then started piston slapping.

Click to expand...

I should’ve been more clear; my comment was to OP with his ‘80 RT. 1980 R100RTs were OEM-equipped with iron-lined jugs, not Nikasil.

Broke my rule, sorry

Well all, I broke my number one rule when answering questions on forums. READ THE QUESTION!

So to anyone who I snapped at regarding my last post, I apologize to you. YOU read the question properly I did not.

I agree, a 1980 RT would have iron cylinders.

Again, I apologize. St.