BMW R 1100 RS Spring 2017

Spring Maintenance 2017

This springs maintenance consisted of a little more than the scheduled service. Those who read about my last trip in 2016 may recall that a seal on the front fork started leaking. During the winter, I took the front suspension apart and put in new seals, bushings and dust caps on both front fork. New fork oil from BMW, was filled in. Thus, I have replaced all fluids on the bike since I bought it. I changed the brake fluid before started riding the RS in the summer of 2015. Then, motor oil, the transmission oil and the oil in the rear axle was changed. The only fluids that are not replaced are in the battery, and the shock absorbers.

The tires were well worn on the autumn tour last year and they are now replaced. I have chosen Bridgestones this time too. At the front, I have mounted a T30 EVO GT 120/70ZR17 while the rear tire is a T30 EVO 160/60ZR18.

When the wheels were off I took the opportunity to replace the brake pads as well. The originals may have lasted one more summer. However, I thought it may have been some development when I comes to pad material in the 18 years since the bike was new.

Then there was the engine. The scheduled valve check was made and a small adjustment performed. Quickly and easily.

As I should mount the cylinder head cover on the right cylinder I got a problem. I had noticed that the bolt was I bit hard to turn when I took the cylinder head cover off, and when I should mount it back the bolt would not bite. I had noticed that there was something strange about this bolt when I checked the valves last spring, but I managed to get the prescribed 8 Nm of torque when I tightened it. But now I was not even close to the 8 Nm torque. The threads in the cylinder head was ruined.

This just had to be fixed and I contacted a friend who runs a workshop and asked if he could lend me the tools needed to insert new threads. He just had to have the bolt so that I could borrow tools with the correct thread size and pitch. With the correct tools, it took exactly 10 minutes from I opened the garage door until I had installed the new threads. With the threaded pin I “drilled” treads for the new HeliCoil treads. It was very easy, and I was a little surprised how soft the aluminium in the cylinder top is. Then I inserted a HeliCoil thread. I then put on new gaskets and mounted the cylinder head cover. Solid thing this HeliCoil.

The equipment for assembly of loose threads are expensive, and it pays off to stay within the producers recommended. 8 Nm prescribed by BMW for the top cover bolts are incredibly low, and with a standard wrench it is easy to put too much force in to it when tightening a bolt. I have two torque wrenches covering all the relevant torques prescribed by BMW for the RS and use them everywhere BMW has set a torque.

The spark plugs were inspected when I had the cylinder head covers off.

The dynamo belt was examined too. It was replaced last spring and was still as new.

I have been annoyed by a noisy idle and especially just after starting the engine. This, I have read, is caused by a faulty cam chain tensioner on the left side. The tensioner sits slightly awkward positioned behind the throttle body. I had to disassemble the throttle body on the left side. The assembly of cam chain tensioner was straight forward, it is however very cramped between the cylinder and the swing arm mount, so my patience was put to the test there.

As I had the left Throttle body off I had planned to change the intake pipes, those from the air box to the Throttle body. I took off the right throttle body too and mounted new intake pipes from the R 1100 GS. They are longer and narrower and gives more torque at low revs, but at the same time I must take farewell with some of the power at the top of the rev range. This I no great loss, most of the time is spent in the lower part of the rev range.

The removal and replacement of intake pipes were easy. But when I was going to put the pipe the into place on the right-hand side throttle body, I got an unexpected problem. To seal the connection there is a rubber O-ring seal located in a groove in the throttle body. On the left side, the O-ring was laying neatly in the slot, but the right side the O-ring was too large. I experienced the same problem when I was going to mount the SW-Motec holder to the tank bag and had to dismantle the tank lid. The O-ring seal lying under the tank lid was more than 1 cm too long. The reason for this is that some rubber can expand when it comes in contact with gasoline. To make the O-ring fit I cut off 1 cm, heated both ends and glued them together.

This time I wanted to try another method. I took O-ring in to the kitchen. Put on the oven with hot air and 150 degrees Celsius. I made an outline of the O-ring on a paper, washed O-ring and put it on a baking paper in the oven. After 20 minutes, I took it out; put it on the outline I had made and voila: the diameter was reduced by 3 mm! I left it in the oven for a few more minutes. Next time I took the O-ring out of the oven it had a perfect fit! The Downside with the method is that I now had a kitchen with the smell of a petrol station. I had to initiate a large-scale venting to preserve the family peace. It’s fun when unexpected solutions work. And after just over a half hour of venting the kitchen was back to original condition.

Next point was change the oil and oil filter. I filled Castrol Power1 15W-50 up to the prescribed amount. First I had run engine to heat the oil. The engine started at the second attempt and run very quiet – the new cam chain tensioner did the trick!

Now I just have to finish the skiing season, then I’m ready for the first motorcycle trip.

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