R69S restoration

[808Airhead]

Today,2/17/11 was a great day,I finished up the last 2% of the actual build, which entailed getting the dry cell battery connections hooked up with a inline 10 amp fuse,then installing the horn as well as putting in the tail light bezel screw.
I got very lucky with the tail light bezel screw,since I did a last electrical check I noticed there was no screw holding the tail light
bezel to the fender,and was going to ride the bike for the first time today and it would have been a bummer to have the whole tail light assembly falling off at speed!!
After dodging a small bullet I was ready to ride it for the first time! I had started it and let it run for a few minutes while checking things,and this was repeated a few times,never letting it run more than
3-5 minutes at a time. This allowed it to heat cycle enough to re-torque the heads and adjust the valves. The exhaust tighened up a .001" or so,the intake was the same .006",and with a quick idle adjustment I was ready,the time had come........
After running a pre-flight check,I fired it up and this bike always starts up very well so far,and within 1-2 kicks she popped into life,with a mechanical symphony which was music to my ears,which was now real,instead of all of the imaginary visions I have been daydreaming about since I started on this journey. I had been dreaming of this day for over a year,and here it was,about to happen,it is a anxious,as well as joyous time,since it could be a very good day,a small personal triumph,or a day of wondering "what that knocking/grinding noise could be",and tearing it all back apart again.........
I roll it out of my garage,click it into gear,and the neutral light turns off,so far,so good,and let out the clutch and it is quite a rush to be riding this bike for the first time,and it is utter joy.
The bike has a very noticable power advantage over my R 60/2,and drove very tight & straight,and the transmission,final drive,engine are all doing thier thing with no oil leaks,and and no unusual noises ............THANK YOU,MOTORCYCLE GODS!
It was quite a relief to have everything working well,however into a 10 minute ride I would let off the gas and it would die out.
I put this down to carb adjustment and turned the idle screws up,and adjusted the mixture. It seemed Ok,althought the bottom end started feeling soft,and it would still die out intermittently. When I get back to the garage I proceed to adjust the carbs and it would keep dying out. I pulled a plug and they were black-ish. I then opened the gas cap and it made a "phoosh" sound when it was relieving pressure,which never happened on my other bike.
I put the cap on,thinking nothing of it and ran it again and it did the same thing,and when I opened the gas cap,it had the same pressure release sound,and realised that the gas tank was building pressure and forcing its way to the carb jets thereby flooding out my bike!
This was a repro gas cap from S.Meyer,Germany and had the little ripples under the cap for venting,however I had to drill a small 1mm hole and now the idle is rock solid and not as much fuel leaks out of teh floats after turning off the bike as well as no more fuel pressure in the tank!
You woud think a gas tank would make vacuum from fuel draining out into the carbs,however the "sloshing" of gas makes it expand,and actually was causing a pressure buildup due to no tank vent.
The only way I could prove this is to tell you to shake a small gas can lightly,then open it up and it will have pressure inside!
Aloha!

[schrader7032]

What an experience that must have been! And pretty satisfying after all that work. About 5 years after my rebuild, I'm still amazed that I don't hear those awful grinding or knocking sounds, but I'm starting to let that go and just accept it as it is and that maybe, just maybe, I didn't "eff-up".

As to the gas tank pressure, when I was first reading your post, I said how could it be building pressure...it should be building a vacuum as you suggest. Of course, the fuel decrease is really pretty gradual when you think about it and with just about any venting or small air leaks, that vacuum would be offset by air seeping back in. But your situation still sounds unusual. I don't recall reading anyone mention that their tank built pressure. I could see that heat could do that, especially in a situation where there was a lot of trapped heat like behind a fully enclosed fairing or maybe due to extreme outside temperatures...hmmm, you do live in in Hawaii But if you have the cause and effect figured out without a solution, there's only one thing to do...ride!!

[R60 Sweden]

Waiting to feel like you ( Ihope for the mercy of the gods of mc, too!) when the r60 is rolling out. At the moment I have to get stuff inside as the garage really is a little cold in this -25 celsius cold. And my wife appreciate it, well, not fully!

But I'll have it running this year.

Interesting little story about the gastank...

[loftus7608]

Nice job getting her out of the garage and onto the street. Happy riding! It must be very satisfying after all those months. And it is amazing how these bikes will start right back up after all its been through!

[808Airhead]

Kurt,I agree with you,it is probably heat, causing the pressure,and yes,I am glad nothing is "effed up".......haha
R60 Sweden,I know something your wife will TRULY appreciate and you can also get some work done on the bike.
Simply move the bike into the kitchen or living room,OR bedroom if your wife is really nice.
If she protests,simply tell her,"this is how bikers work on their bikes,if it is good enough for the Hells Angels,it's good enough for us honey." Wives fall for it all the time.
You can thank me later.......
Loftus, I am glad you can understand the excitement of bringing something back to life and hearing it run for the first time,it really is like "mechanical birth",very cool to see a machine doing what it was designed to do (ride),vs. sitting in a dilapidated state waiting for rescue.......or the scrap heap......
I have this funny thought about the Karma of the machines that "come our way",and think "wow,how lucky is this machine?,to come into the hands of a thoughtful owner,instead of someone that would destroy it,like many others have been." Someone could have sold this bike for parts,or,who knows?
It is a great feeling to have rescued this mechanical work of art known as the "BMW R69s,the worlds finest motorcycle"
and a even better feeling when I ride it.
Hope this is some inspiration for some,finish those projects,summer will be here before you know it! Aloha

[privateer]

Great job on the build 808 ! im about two months behind you on the build on my R50 so your thread is a great inspiration to me. Installing the bottom end next week (the wife had a confused look when i told her i need to drag her oven into the shop for a day or so).

[808Airhead]

Good luck with the completion of your project! I stuck mine right in the oven and thankfully it was grease free,so there was no smell!

[R60 Sweden]

I'll start to lug in the engine right this moment! She's not home so it'll be like a surprise when she's back!!!

[Darryl.Richman]

I'll start to lug in the engine right this moment! She's not home so it'll be like a surprise when she's back!!!
=)) =)) =)) ) )

I hope your wife has the same kind of sense of humor you seem to have!

(BTW, it's possible to do this job with a propane torch in the garage.)

[808Airhead]

Update.......135 miles on here so far so good except..........a couple of times i had hard starting when hot,and I attributed this to not turning off the petcock before I killed the ignition. If I would turn off the fuel and let it run for almost a minute,then restart it,it would start fine.
However a couple of times afterward I got a NO START,I mean,kicking it 20+ times and nothing..... I went for a 20 ile ride and 2.5 miles from home she dide out at a traffic light and would not start.I had to wait for 1.5 hours ad then like magic,she started!!
I blamed this on the original coil that appeared in perfect condition,and worked fine at first.......
I installed my "Emerald Isle"/Benchmarkworks repro coil and she now has a smoother idle and faster startup,so I am hoping this will cure my hot start issues!! Wish me luck!