My keeper, maybe. 58k, RT exhaust so I can fit full size panniers. Corbin matched seat. Full engine bars hand guards Cruises all day. Mint and light enough to enjoy. Had R100 RS, RT, two R100GS. R65, R80. K1100. 1150 GS. R90S for 10 days,rebuilt gearbox and flipped it for a £1500 profit should have kept that one. Love the old boxers.
The guy had broken a lug off the back of the gearbox when rebuilding the bike. He had used a stainless bolt to pivot the actuator arm, over tightened and ping. Should have used the original hardened pin with a circlip on both ends. Seen this done a few times! Can not be welded, distorts casing so needed rear gearbox cover and all end floats set. He had spent a fortune but lacked a lot of basic fitting skills. He just gave up when he was quoted for gearbox out and rebuild. Took a day to complete plus case, gasket and oil, so good return! 20 years ago. Love the boxers, few special tools and totally logical simple tough engineering. Happy days
View attachment 238471 So one thing lead to another..... I had to remove the engine to have the frame powder coated but the front engine mounting stud was seized solid in the engine. After almost 2 weeks of heating and trying all types of penetration oil including a home made mix of ATF and acetone, I resorted to cutting the stud to remove the engine. So I took the engine to a local machine shop to have the stud drilled out. It’s around 12” long. Picked the engine back up and decided it would be a good time for a full tear down to a bare block. Media blasted the engine block, quite happy how it turned out.
Bottom end rebuilt, all new bearings, shells and seals. Oil pump inspected ok and refitted. New timing chain and tensioner. Sprocket teeth were like new even after 30,000 miles
R80s where good for 80k min if oil changes followed the 3k oil 6k filter change. Seen one with double that. Over engineered, under stressed simple motors. Get a move on, no slacking now
They were normally split link across the range. Not sure from 1100 series on. Makes fitting far easier across two fixed sprockets. Limited adjustment by the chain tensioner. All heavy duty on a 50 bhp motor. Love em!
Engine block back in the freshly Powder coated frame. Barrels and cylinder heads fitted. Timing chain cover power coated then sanded. Really starting to take shape.
Turns out I do know my way around the kitchen. Oven set to 200c to expand the cylinder barrels to allow the replacement stainless pushrod tubes to be fitted. The tubes have been in the freezer overnight. This is also around the same time I realised the dish washer is basically just a parts washer
As far as I can see even the current R1200GS engines have that same chain-driven arrangement for a shaft below the crankshaft, which now has sprockets on it to drive separate camshafts in the cylinder heads. I don't think BMW have dabbled with belts for camshaft drive in motorcycle engines and even with cars they went back to chains after some difficulties with belts, not that chains are problem-free in all cases (especially if oil is not changed frequently enough, as can be the case with "longlife oil" and computer-managed service intervals). https://www.bikebandit.com/blog/motorcycle-history-the-bmw-motorrad-story
Oil is the cheapest simple maintenance on any motor. £40 every 6k miles! Long life oils may not shear but they do not remove crap or clear filters. Belts many advantages but chains take some breaking. There's a song there! Many chain songs. All day now chain songs in my head!
Love airheads. Part way through my R100R rebuild. Was set on fire so using it as an excuse to upgrade pretty much everything.
I'm one of the chain gang too... Re Oil....spot on, and on these engines its well worth using a normal 20/50 mineral oil as used at that time...one with a high phosphorus/zinc content is best such as the Pistoneze range from Opie Oils. They run noticeably quieter and smoother....
