Newbie with a broad question.

Kneedrager · Post by **Kneedrager** » Wed Jun 19, 2013 11:20 am

My name is Scott and I'm new to the forum. The user name is from my former life as a Superbike racer. I've been wrenching on old BMW cars (mainly E30's) for a few years and decided to look into getting an older BMW motorcycle. I've found a 1974 R90/6 for sale that the oil plug was never tightened, vibrated out and seized as a result of a "NO" oil condition.
The Owner says he pulled the cylinders and can not get the connecting rods to move (not too much of a surprise there). Not being familiar with these motors I am wondering what else could have been affected by no oil. I realize that everything could have been affected, but am trying to figure out what I may be getting myself into. Crank, bearings, valves...? Is this a toss the motor and start again situation?
Any and all help is much appreciated.

iagins · Post by **iagins** » Wed Jun 19, 2013 11:31 am

If he was able to pull the cylinders off, there's hope for the top end. But it sounds like the bottom end is toasty.

It depends what you want to do. If you like wrenching and the satisfaction in resurrecting the bike, it may be for you.

If you're more interested in riding it, there are currently four R90/6's for sale on the IBMWR Marketplace, ranging in price from $2500 to $5500.

Ira Agins
Santa Fe, NM

Kneedrager · Post by **Kneedrager** » Wed Jun 19, 2013 11:45 am

Thanks for the reply. For me (as weird as it sounds) wrenching is half the fun. Bringing something that doesn't run back to life offers a certain, definite satisfaction. Sometimes I get to the end of my workday and look back and wonder "what did I actually accomplish today?" When you're wrenching, you can see (and hopefully eventually ride / drive) the fruits of your labor

2valve · Post by **2valve** » Wed Jun 19, 2013 7:34 pm

very honest reply and yes good to see abused / damaged bikes returned back to life ! like your forum name but expect to drag the tappet covers on the BM through tight corners ( horrible sound , for me anyway ).any pictures of the bike youd like to share ?

Kneedrager · Post by **Kneedrager** » Thu Jun 20, 2013 5:44 am

It's a Craigslist find...
He wants $3,500 which seems a bit hight to me considering the condition.

schrader7032 · Post by **schrader7032** » Thu Jun 20, 2013 7:12 am

From the picture, that looks like a pretty nice specimen...$3500 doesn't seem all that out of line. One of the issues...supposedly...with the '74 model is the 5-speed transmission. First year for it and it was somewhat weak. If the transmission requires overhaul, you can't get some of those parts and the best thing would probably be to find a later 5-speed and swap in. Also, the "lore" is that the kickstart mechanism is also really just for emergencies...the internal spur gear can break and cause additional damage to the tranny.

2valve · Post by **2valve** » Thu Jun 20, 2013 7:53 am

had a R90/6 for over ten years or so, what a beautiful bike it was too ! had a R90S fairing / instruments on mine and regret selling it ! looks like the bike your looking at it has been updated a bit , new style fuel taps / R90S fuel cap. is it just the picture or is the side of the gearbox oily ? the chrome strip around the base of the seat is missing and as seen before the tab on the centre stand is missing, braided front brake hose ? other than that i can see of the pictures looks very nice. as schrader has commented about the early style of kickstart gearbox is a bit of a nightmare .

Kneedrager · Post by **Kneedrager** » Thu Jun 20, 2013 10:31 am

Thanks for all the replies and good information. I really going to show my ignorance now... Is the transmission a separate item (with separate cases) bolted to the motor, or do they share a sump similar to Japanese bikes of that era?

schrader7032 · Post by **schrader7032** » Thu Jun 20, 2013 11:31 am

Transmissions are separate and have their own 80w90 gear oil.

khittner · Post by **khittner** » Thu Jun 20, 2013 10:58 pm

That was a $3500-$4000 bike before the engine seized. It's now a nice-looking $1000-$1500 paper weight. You'll have to find another bike for a complete engine transplant, or spend a ton bringing the original back into operation. Bearings, con rods, camshaft and valve train, bores, pistons and rings, etc. After that, you can then deal with the '74's transmission issues . . . and when you're all done, you still only have a fairly nice R90/6---not a device that's going to set Airheads' hearts aflutter at the next rally you get to.

Buy it if you really do want a project, but don't overpay for it.

Konrad

Vintage BMW Motorcycle Owners

Newbie with a broad question.

Newbie with a broad question.

If he was able to pull the

Thanks for the reply. For me

hi Kneedrager

It's a Craigslist find... He

From the picture, that looks

looks good to me

Thanks for all the replies

Transmissions are separate

That was a $3500-$4000 bike