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Greetings and Felicitations

fatal

Well travelled
Location
Lancashire UK
I replaced the original as I didn't like the tiny flyscreen with the larger Wunderlich screen fitted. The side stand is a rare Migsel item from a bloke in Belgium. My engine was standard, but I'd replaced the timing chain and tensioner, fitted new valves, seats and springs, upgraded diode bord and alternator, Hagon rear shock and front progressive fork springs. Tears are welling up now, sellers remorse is awful:cry: :D I used the money to buy a Ducati Multistrada, bad move.
 

Lavrentyuk

Getting there...
Location
Wales, UK.
I replaced the original as I didn't like the tiny flyscreen with the larger Wunderlich screen fitted. The side stand is a rare Migsel item from a bloke in Belgium. My engine was standard, but I'd replaced the timing chain and tensioner, fitted new valves, seats and springs, upgraded diode bord and alternator, Hagon rear shock and front progressive fork springs. Tears are welling up now, sellers remorse is awful:cry::D I used the money to buy a Ducati Multistrada, bad move.
I put Dual Plugs on mine - made a remarkable difference to its pick up and starting reliability in cold weather - even though I'd been running electronic ignition already. Did a valve and guide job at the same time.
If/When it goes back on the road I see the expense of Siebenrock cylinders/pistons in my future as I understand the original liners don't suffer a rebore reliably.
 

fatal

Well travelled
Location
Lancashire UK
The siebenrock parts do seem to work well. I never had many problems as such with any of the airhead beemers I owned. I found that keeping the carbs balanced and valves adjusted was important for smooth running. Unfortunately I've lost/misplaced the photos of my other airheads. I had a 1979 R80/7, 1978 R100S, 1985 R80ST and 1990 R100GS, and an 2002 oilhead R1150GS. I much prefer them to the modern post 2005 BMWS.
 

Roy Gavin

Well travelled
I put Dual Plugs on mine - made a remarkable difference to its pick up and starting reliability in cold weather - even though I'd been running electronic ignition already. Did a valve and guide job at the same time.
If/When it goes back on the road I see the expense of Siebenrock cylinders/pistons in my future as I understand the original liners don't suffer a rebore reliably.
The Nicasil/Galnicel bore coating almost doesn't wear, so no need for a rebore.
Moteren Israel will sell you the high comp Wossner pistons which Siebenrocck use , but getting the piston head clearance ,squish, set is needed for the full benefit.
My 1000cc R80 G/S PD came with twin plugs but it was a vibratory slug - a Boyer Micro Power system with the right twin plug curve fixed it, but I had the timing set on a dyno and can't see the timing marks!
 

Lavrentyuk

Getting there...
Location
Wales, UK.
The Nicasil/Galnicel bore coating almost doesn't wear, so no need for a rebore.
Moteren Israel will sell you the high comp Wossner pistons which Siebenrocck use , but getting the piston head clearance ,squish, set is needed for the full benefit.
My 1000cc R80 G/S PD came with twin plugs but it was a vibratory slug - a Boyer Micro Power system with the right twin plug curve fixed it, but I had the timing set on a dyno and can't see the timing marks!
Indeed, mine is older and has plain iron bores though. Also the horrid 'antilock' ATE brakes (sarcasm intended). I'm not losing too much sleep over it, its a when I get round to it project, and medical bills in the UK need paying first.
 

Roy Gavin

Well travelled
The iron bores are cast in using the Alfin process, but they can be bored out with if the machinist has the correct gear .
They need to be as close to working temp as possible and torqued down with a six bolt torque plate, then you can go up to the next size.
Probably easier to buy secondhand plated barrels ---!
A 11mm master cylinder livens up the brakes, Moto Guzzi fitted one to a similar perch so they are around.
 
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Lavrentyuk

Getting there...
Location
Wales, UK.
The iron bores are cast in using the Alfin process, but they can be bored out with if the machinist has the correct gear .
They need to be as close to working temp as possible and torqued down with a six bolt torque plate, then you can go up to the next size.
Probably easier to buy secondhand plated barrels ---!
A 11mm master cylinder livens up the brakes, Moto Guzzi fitted one to a similar perch so they are around.
I have a replacement Master Cylinder waiting - and have had for some time - quite keen to move away from the under the tank setup. Reborers in the UK are really not keen on the iron liner R100 - Siebenrock are the go to. I've had the bike from about 1986.
 

Roy Gavin

Well travelled
I swapped from a undertank to handlebar M/C and went to twin disks at the same time on my R75/7, needed the 11mm M/C but even with it it doesn't even match the Hima.
I converted my R80 G/S PD to 1000 cc with secondhand '"Nicasil" barrels from Ebay and the "Siebenrock" pistons from Moteren Israel for around half the cost of the full Siebenrock kit 200,000 km back and it is still OK.
Bored the 75/7 out to 900 twenty years ago and it is still fine, but it was done properly by a BMW nut who also ran the cities biggest machine shop and had the gear.
FWIW most R90S racers were 750s bored out to 900 to get decent small ports and combustion chambers- and no sense in spending an extra $3000- dollars for a paint job and a cam you weren't going to use!
 

Lavrentyuk

Getting there...
Location
Wales, UK.
I swapped from a undertank to handlebar M/C and went to twin disks at the same time on my R75/7, needed the 11mm M/C but even with it it doesn't even match the Hima.
I converted my R80 G/S PD to 1000 cc with secondhand '"Nicasil" barrels from Ebay and the "Siebenrock" pistons from Moteren Israel for around half the cost of the full Siebenrock kit 200,000 km back and it is still OK.
Bored the 75/7 out to 900 twenty years ago and it is still fine, but it was done properly by a BMW nut who also ran the cities biggest machine shop and had the gear.
FWIW most R90S racers were 750s bored out to 900 to get decent small ports and combustion chambers- and no sense in spending an extra $3000- dollars for a paint job and a cam you weren't going to use!
I hadn't realised that racers preferred to bore out the 750, but given the price differential alone I see the point. The thing I like least about mine is the ATE brakes tbh. Otherwise, great machine.
 

fatal

Well travelled
Location
Lancashire UK
The ATE brakes left a lot to be desired, on both the R80/7 and the R100S I changed the under tank master cylinder to a handlebar mounted Brembo item from a later model. It helped a little, better feel to the lever if anything.
 

Roy Gavin

Well travelled
Pity you are not in Oz, I have a Showa front end from a brick complete with nice big 50mm Brembo calipers and disks I bought for a project I never got round to you could have for a song.
Could probably dig up a pair of Nicasil barrels too.
I used to put silly low bids for BMW on Ebay and occasionally won stuff I have never ended up using!
 

Lavrentyuk

Getting there...
Location
Wales, UK.
Pity you are not in Oz, I have a Showa front end from a brick complete with nice big 50mm Brembo calipers and disks I bought for a project I never got round to you could have for a song.
Could probably dig up a pair of Nicasil barrels too.
I used to put silly low bids for BMW on Ebay and occasionally won stuff I have never ended up using!
I have the remnants of many BMW gearboxes and other lumps. MZs - too many to mention.

Thats why after many years keeping old stuff running I ended up buying an Interceptor so I could just jump on and ride. Still running a few MZs - one with a sidecar - as I find they breed in captivity.
 
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