Pre-Restoration Questions

I’m in the planning process of restoring my 88 R100 RT over the winter.

The bike is ±34 years old with ±105,000 miles and some things are original. The plan is to powder coating the frame, go through the important systems and rebuild them, and give it some fresh paint.

With regards to brakes, my thought is to rebuild the master cylinder and brake calipers in addition to replacing old brake lines. However, both master cylinder and calipers appear to be working fine.

In rebuild process, I’m planning on replacing the timing chain, so all seals and gaskets will get replaced. Also while things are apart, I’m thinking on replacing the rear main seal, since its 17 years old.

I’m on the fence regarding the transmission and final drive. While both are working great the seals and gaskets are 10-15 years old. FYI, working on both of these are beyond my expertise and I would have to ship these off to have them worked on.

What are people’s thoughts? Should I be proactive and rebuild the master cylinder, calipers, transmission, and final drive or wait until the seals and gaskets start leaking? Or, should I be proactive and get them working like new?

On a different note, I know I’ve read of people’s suggestions on restoring the look of the engine, but I’ve not been successful in locating the previous discussions. What are people doing to restore the exterior look of the engines (dull grey aluminum to more shiny aluminum)?

Welcome to the task

Hello and welcome to the task of restoring an airhead. I have done my 84 R80RT a couple of times with varying amounts of work involved.

I am still going strong on my transmission with over 240K miles on it, nothing has been needed with it other than regular gear oil changes. Main thing to check is the input shaft splines for wear. If you kept up with lubing them on a regular basis, you shouldn't have problems.

I am also on the same number of miles with the final drive and drive shaft system. Of course, I have changed the drive splines a couple of times but, never had to do anything with the insides. I am afraid I don't know much about the 88 final drive, mono shock to my dual so I won't write much about the newer unit.

The engine seals are a plus to replace, especially the main seal and oil pump o-ring. Gaskets and seals are not expensive I found on friend's bikes if we didn't replace a long lived main seal when we had the bike apart to get at it, it would start to leak shortly after everything was back together.

The timing chain is a must, I got about the same miles out of my original chain on my bike.

Despite many glowing reviews of Nikasail jugs and the rings and pistons to go with them, I would very much advise you measure the cylinders for roundness and shape. At 125K my pistons started slapping the cylinder walls, the rings were shot. The cylinders were damaged beyond repair and at the time, it was crazy money to replace them with stock BMW units. I ended up boring out the Nikasail and putting in cast iron sleeves. Of course, this meant. new rings and pistons. At that time, I bumped the 8.5 to 1 compression to 9.5 to 1. Now, there are complete Nikasail kits available on the market that are getting good reviews and cost less then BMW stock. If I were to have to replace cylinders again, that would be the way I would go.

If you have been doing regular oil changes and haven't noticed any metal bits in the filter, I would not bother with rebuilding the crank bearings or cam. I have my originals in my engine. You can do a visual inspection of the cam lobes when the lifters are out.

As for cleaning the cases, well, my last restoration over this past winter saw me using a lot of elbow grease and cleaners of different makes. I did soda blast the engine block but I found out the hard way, it has to be completely stripped of ALL parts before soda or any kind of media blasting. I found out the hard way, soda gums up and does not alway dissolve when it should. It also got places I didn't expect it to get. As a mild abrasive, it would be a disaster to get any inside the engine. To be honest, I would perhaps try walnut shell blasting next time. I found simple green and elbow grease did the best, aside from the soda.

My last overhaul this winter saw me replacing all the wiring harnesses as mine were in bad shape from years of riding in all kinds of weather including winter here in NY. Inspection of your harness's terminals and such will give you an idea if you need to replace or not, honestly if you don't ride in the conditions I do, you most likely won't need to do anything more than clean things.

Winter is the time to do it, I spent a lot longer on my project due to my paint guy taking a lot longer than I expected, I guess that is one of the things most everyone runs into. Brook Reams has a lot of video regarding restoring bikes, there are others on line as well. Frankly this second time around was easier because of all the internet stuff out now.

LOL, don't do like I did, bag and tag ALL your parts, the more bags and tags, the better time you will have putting things back together. I had a major memory loss when I opened a bag of hardware and couldn't remember where it went. Oh yes, one thing I did and I liked was I ordered a stainless steel bolt kit from the bolt guy. Mind you, it is only about 75 or 80% of what you will need, mainly visible bolts but, it is a nice touch to have nice looking hardware when you have spent the money on powder coat and paint.

If you are near Rochester, NY, give me a holler, there is also a good airhead shop in Niagrara county as well. Good luck, have fun. St.

I would rebuild the brakes and put on steel brake lines for safety. If you rebuild the calipers, get some red rubber grease for reassembly. It makes the job much easier.

Brake lines

Yes, the stock brake lines are only so good. One of the things I did a long time ago was to ditch them and install braided ss lines. The original pair of ss lines I installed lasted 200K miles and I just replaced them not because they didn't work but because they looked like they had been in a war. Old lines with new paint chrome and powder coat, just wouldn't do. St.

Just for clarification ... Spiegler, etc., brake lines are Teflon, protected by metal braiding. They are not steel lines and they are not ss lines.

sorry

Sorry, I use the generic term ss brake lines to mean anything other than the OM BMW lines. I have Speiglers lines on both bikes. They are very good. St.

STEVENRANKIN said:

Sorry, I use the generic term ss brake lines to mean anything other than the OM BMW lines. I have Speiglers lines on both bikes. They are very good. St.

Click to expand...

I have some (Speiglers that is) in a box ready to be installed, but it doesn't seem to make sense to install them now, only to disassemble the bike in a few months.

Lol

LOL, if you are going to take things apart this winter to restore the bike, a few months more of the original brake lines won't hurt unless they are bulging or leaking or cracked. Believe me, you will have your hands full with the work at hand restoring without doing things twice.

Oh by the way, don't believe your paint guy when he tells you how long it will take, LOL, double the time. Chrome, powder coat assembly took expected time in my restoration. The paint took twice the time or longer. If you have a fairing, there is a lot of extra fiddling for a painter to do. Gas tank, side cover, fenders don't take as long. St.