Monday, August 24, 2009
BMW R100S Sidecar Tug Progress
I dis assembled the R100S engine top end a few months ago after soaking it in "Marvel Mystery Oil" for 6 weeks. The left side cylinder was rusted but freed up after sitting in an oil bath. After a long soak I would raise the rear tire off the ground, put the transmission in 5th gear and then rock the drive wheel forward / backward. After a few tries the rust lost its' hold and "free at last". I found that water had entered the left intake port and sat in the cylinder. I hauled everything to a competent engine shop and had the cylinders honed and the valve seats freshened up. The pistons looked good and a fresh set of standard rings should be good. They found that both the exhaust valve guides were sloppy so I ordered a complete set of new guides to be replaced. One cylinder shows minor "stains" after honing but hopefully will be OK. They looked just like the (earlier rebuilt ) R90 cylinder "stains" which have now run 14k miles with no issues.
This is the finished (was Blue) R90/6 tank that I had as a spare. It went in for body work and paint...then onto EBay ......now in the hands of a new owner.......I only profited a few dollars on this one but now a fellow BMW guy has a nice newly reconditioned tank.
I sealed the intake / exhaust ports with clamped caps to retain the oil during the "soak". The exhaust valve was open so it wouldn't hold the oil.
The QSL 1000 Mile Solo seat back from the upholstery shop. A whoppin $90.00 for a recover. Into the seat about $200.00 now. .....It's worth that much.....I installed it (and the tank below) on the "Black Hag" for a trip or two and it is very comfortable. I like the black QSL seat better than the old brown QSL as the foam is thicker & newer.....I swapped the mounts around and now have this seat permanently on the "Hag".
This old "German Cop Tank" worked good on the "Hag". Fuel capacity only at around 5.5 to 6.0 gallons so fuel stops were more often...I like the Heinrich Tank much better. This tool bin holds the stock tool kit just right, but no extra stuff.
I've received all the new engine parts needed to assemble the R100S engine so hope to get it together in the coming weeks. I got lucky and found a set of real nice vintage "Luftmiester" header & muffler shields via the IBMWR site for $45.00. What a find! I wanted another set for the "new" bike. I've seen just the header guards sell for over $100.00 on EBay.
Slow but sure the R100S stuff is stacking up......Had a /5 friction damper rod modified to fit the leading link forks on the R100S also.
I purchased a 1973.5 long wheel base rear sub frame to install . (EBay) upon receipt and inspection I found the frame had a crack in it......the seller said he would cover the cost of repair.....I had the machine shop repair the frame and hope the crack repair will hold. The 73.5 sub frame uses two pipe cross braces and will fit the stock QSL seat mounting frames. Slso the 1974- on cross braces are very prone to cracks at the welds. ( mine was cracked and has been re welded) It just dawned on me that the bigger battery will not squeeze into the holder with the different sub frame.....I'll likely use the smaller style battery......
Parts for R100S: reconditioned 40MM Bings with K & N Pod Filters
repaired the sidecar lower mount sub frame (minor bend from crash)
reconditioned /6 German Cop Touring Tank W/ tool box
reconditioned QSL 1000 Mile Solo Seat
Modified /5 Friction Steering Damper (rather than hydraulic)
"Luftmeister" muffler & header shields
32:10 Final Drive
5 speed kick start transmission
new top end / seals & gaskets
I surely hope the engine bottom end is good. The engine showed 45k miles but with the exhaust guide wear I'm not sure if that is correct....I have a pair of spare lower end engines in AZ. if needed. I'll go with the engine bottom end as is and we'll see........It was running good when wrecked....I sold the R100S 5 speed transmission to a guy in Ca. and it worked great with no seal leaks at all.....it sat for 12 years or more.......