73 BMW R75/5

Autotek

You cant put a price on awesome.
I know it more fun for the viewer when we wait til a bike build/ restoration is further along but I'm gonna start right in. I have a 79 Bonneville in progress but the engine build is out of my hands so I have taken on a couple side builds. Some of you may have seen the KZ400 I recently finished...
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I picked this up from my neighbors yard sale about a week ago.
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It has under 19,000 original miles and is in relatively good condition. It has been in a garage for nearly 20 years and out of the weather but sitting so long has seized the engine. It is likely the pistons so I pulled the spark plugs and sprayed a hefty amount of pb blaster into both cylinders. My plan is get the engine free, clean the carbs and try to get it running before any major changes.
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After I am sure the bike runs ok I think I will do some cafe treatments while keeping all parts and not cutting it up in any way. I prefer the cafe look but want to be able to go back, ( if the market for this original bike rises considerably ).

The inside of the headlight bucket/ wiring lots like new...
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So this is the beginning... Ill keep you posted. Autotek RVA
 
Hoosier Daddy said:
Awesome score!

You know, I have never been a huge fan but its really growing on me. I think with the right seat/seat cowl, bars and probably removing the fenders and new mufflers, tires, brakes, cables, paint, it will be sweet. AKA $2000 haha I need to sell two bikes.
 
Excellent score. Watch the exhaust flanges. They bond to the head after sitting for a while. If they seem to loosen a bit and then get tight again, don't force them. Use the good old PB blaster and some heat a few times. If that doesn't work, carefully cut off the flanges and replace them. A lot cheaper than having the head machined. This is a common problem on Beemers.

Is it a long wheel base or short wheel base? The LWB models have about a three inch section welded into the swingarm for the length. It's near the rear wheel. They handle a bit better than the SWB models, but some guys would never admit that.

I really want to get a /5. It's the perfect combination in my eyes. BMW really started to get things just about perfected by then, but still had all the classic charm, such as the headlight bucket mounted instruments and spoke wheels. I've had a /6 (same color as yours) and I currently ride an R100, but haven't been able to get the right deal on one like yours.

I hope you enjoy it, but if you ever want to get rid of it, let me know.
 
Its a log wheel base IndieSol, thanks for the interest. I dove in today starting with the carbs. Got them both apart, cleaned and back together. Only one thing lingering with them: there was no spring above the needle jet. When I read in the manual, they say there are three model bings that came on these bikes. One of the three did not use a spring and I dont think it mine. Easy fix fortunately I can do that later if it wont run right.
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So on to the source of the seized motor. I became obvious that it was likely the left piston after inspection of the intake after removing the carb.
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Under the valve cover looks good.
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Pull the head off and OMG!!!!
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Its is likely that this bike got water in the carb, would not run, and was left to sit, for 20 years! So the jug came loose and as well as the rest of the engine but the piston is still stuck like glue.
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Now she is on her side with penetrating fluid for the night.
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I let the piston soak over night and began the beating this morning with no results gave up and when to work. After much thought and determining that I will be buying new piston and boring the sleeves 1 over I made the decision that even if I had to use the cutting torch, this piston was coming out today. Luckily that was not necessary, I did however end up using metal on metal and beating the $hit out of that thing. So here it is, can you tell the bad side? :))
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Bummer about the siezed piston but congrats on getting it apart. A week of soaking with the penetrant may have helped but you got it.
How is the combustion chamber on the head? Is the aluminum rotted away around the valve seats?
 
I just love that you can do all that without dropping the motor. That is a luxury that's unique to BMW's (and I guess some Moto Guzzi's too)
 
I'm too young to "remember" these bikes.... hell this one is older than I am :D but I have a real soft spot for airheads. I'm just waiting for one of "those deals" to come along so I can add a Beemer to the garage. I grew up with dad owning oilheads and K's, and worked as an apprentice mechanic at an independent BMW/Guzzi shop for a while, and I always loved the character of these old boxers.
 
scottyfunj said:
I just love that you can do all that without dropping the motor. That is a luxury that's unique to BMW's (and I guess some Moto Guzzi's too)

You can also rebuild the Honda CB500/550 engines in-frame. I always loved that (did mine twice). I do also love this fact about my R75/6 though I haven't had to do it yet.
 
Hoosier Daddy said:
Bummer about the siezed piston but congrats on getting it apart. A week of soaking with the penetrant may have helped but you got it.
How is the combustion chamber on the head? Is the aluminum rotted away around the valve seats?
It has some rot but not bad. I have the jugs and heads at a local machine shop for over boring and to have the heads checked out. I was surprised how inexpensive the boring is, I was quoted about $45. Nice people.
 
The machine shop had to go 1mm over (which is a second over bore) to get under the pitting on the bad cylinder and discovered cracks in the exhaust valve on the same side so Im having a valve job done to both heads and replacing the one exhaust valve. I am kinda shocked that they only charge 145 to do all of this! At this point I am waiting on parts. zzzzzzzz :mad:
 
I agree, that does sound like a fair price. Boreing both jugs an a quality valve job on two heads. I'd have expected more than that.
SCORE!
 
Hoosier Daddy said:
I agree, that does sound like a fair price. Boreing both jugs an a quality valve job on two heads. I'd have expected more than that.
SCORE!

I see where you live, dont you think you should be building a drag bike! ;)
 
HA-HA-HA!
Some how you got inside my head! I have been gathering info on building one... That's what's planned for my Zookie "Overkill". I've even picked up a longer aluminum swinger from a GS1100. I got a Mate who's a Pro Drag Circuit engine and chassis builder who's been buggin me since I bought it to make an entry level drag bike out of it.
This is Robs he's the guy on the right.
 

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