New R69S member and a couple of questions

ak_in_oakland · Post by **ak_in_oakland** » Thu Oct 02, 2008 5:23 pm

Also, for question number 1 - the horn works as well and is nice and loud.

schrader7032 · Post by **schrader7032** » Thu Oct 02, 2008 9:37 pm

Greetings AK -

1. When the bike is running at an elevated RPM, say 3K (guestimate if you have no tach like most of us), what does a known good voltmeter read when you measure the voltage across the battery terminals? This will tell if your charging system is working or not. It should be 7v or even a bit higher. If not, then your generator is not putting out enough voltage to charge the battery and run the electrics. I'm also not that good on electrics, but I would start at the battery voltage. Without a good output from the generator, your lighting will suffer.

2. There really should be no smoke from the bike...my newly rebuilt R69S does not smoke. Sounds like you need to do a compression check and better yet a leak down test. My guess is you have some blow-by past the rings which is getting oil mist in the combustion chamber and other by-products back into the oil. If the maintenance history is unknown, and it's got 45K or more miles, you really should think about looking into the compression and leakage. My guess is also that your oil slingers are near full or past full, with the potential for trashing your lower end bearings. With the excess blowby, more grit, etc., is getting into the oil and getting trapped out by the slingers. It's a downward spiral. These bikes need slinger cleaning every 30-40K miles or so. This process involves complete disassembly of the engine....the crankshaft has to come of the bike. This is a good time to do the top end with new rings, valves, seats, etc. Do the compression/leak down tests and see what that tells you.

Kurt in S.A.

jrapose · Post by **jrapose** » Sat Oct 04, 2008 2:24 pm

I live north of you about 200 miles....but if you want to bring your bike north I will help you with your charging problem..... I am fairly good with electrical systems on a /2..... (free) Don't worry it probably is something fairly minor....

The smoke.... if you flood the bike to start it....yes it will smoke for a few minutes...but then it should go clear... look at your tail pipe ....is it wet or sooty... is the smoke white (grey/white) or black like a rich mixture ??Oil burning can be caused by lots of things.... all are fairly easy to check...and will only cost you the price of a few gaskets...
But I totally agree about the slingers.... I am going to do mine this winter...acturally we are going to do a few this winter...my riding partner has a R69S and needs his done too.... Want to join us ??

Joel Rapose MZ-B Guy
Chester Calif....

ak_in_oakland · Post by **ak_in_oakland** » Mon Oct 06, 2008 2:00 pm

Hey Kurt, voltage reg looks good...still no lights with the exception of the foot brake light and neutral/charge light. Strange. Found a local shop to take a look at it.

Also re: the smoke...I had just put on a deep oil pan and cleaned out the sump...its possible that either I overfilled it, or my bike doesn't like to be at full on the dipstick, but its now a little below full and there is FAR less smoke. Still a bit, but nowhere near as much.

Joel - was thinking about doing the slingers this winter as well. Would be great to team up with you folks, but the problem is getting up to Chester on the weekends to work on it with you guys! I've got a nice little workshop here in Oakland so I may decide to be bold and give it a try on my own. I'll be doing quite a bit of work on my other bike as well ('65 Ducati cafe racer) - so we'll see how it goes.

Thanks for the advice all!

cheers,
ak

ak_in_oakland · Post by **ak_in_oakland** » Wed Oct 08, 2008 11:17 pm

Hey guys, so did the compression test and leakdown...compression is great, 150 in both cylinders...but leakdown showed 20%. I know 20% is "bad" but how bad is bad?

Time for a top end I guess. Might as well do the slingers too. Any suggestions on improvements while I'm in there? She's bone stock now.

Thanks,
AK

schrader7032 · Post by **schrader7032** » Thu Oct 09, 2008 7:24 am

AK -

I'd heard that anything over 5%, certainly 10%, called for an overhaul. Where was the air leaking? When I did my leakdown test, I took out the oil dipstick and heard a lot of air rushing out of the case (the rings were bad) but none from the exhaust or out of the carb, meaning the valves were propbably OK.

I had to rig up something to keep my piston at TDC on the compression stroke while doing the leakdown test. The pressurization of the cylinder kept pushing the piston down, changing the results of the test. How did you keep your piston at TDC?

Be sure and measure the cylinder for shape and size. If the dimension has grown too much, you might have to consider a rebore. In my case, it was fairly close to stock, so I just put new rings in. The end gap on the new rings was marginal, somewhat near the upper end of the size. I decided to go with it rather than try the next size rings and filing the ends down. Seems to have worked out OK. I suppose I could redo the leakdown test, but I've been a bit lazy.

Of course, new valves and seats would be the ideal especially of the unleaded variety. Valve guides, also. Depending on mileage you could consider new valve springs but that's probably not really necessary. I went with parts from BMW (I believe that's what my rebuilder used). I've been reading quite a bit on another Airheads forum about after market parts that really aren't worth it. One of things that was mentioned was the area of the valve stem where the "keepers" fit...these hold the valve in place against the spring. Some valves are not properly made in this area and some rebuilders will file the keepers down such that the valve is not allowed to rotate on operation. Not sure of your year bike, but in later bikes the valves rotated while in motion thus the valve seat didn't hit the same spot on the seat.

I had the rebuilder change out all the bearings...unknown condition, I figured why not. I suppose he could have declared some of them good, but I didn't want to take the chance.

Pushrod tube seals are called for. Since you have the tranny out, check out the input seal to the tranny. My clutch seemed OK after only about 30K miles so I reused all parts.

Those are the things that I did on my mechanical restoration.

Kurt in S.A.

saintclair2703 · Post by **saintclair2703** » Sat Oct 11, 2008 9:06 am

Have you noticed there's no brake switch on the hand brake yet?
Might try checking the generator brushes, they seem to wear down reliatievly quickly. If the wires are too close tho the brackets that hold the brushes, they may not be rubbing good.

bpw · Post by **bpw** » Wed Nov 19, 2008 2:01 am

Hi AK,

Not able to help much with your problem since I just got my 1965 r50/2 this weekend but I live in San Rafael, When you start tearing down your engine I would be interested in lending a hand so I could get a bit of a preview of what I am in for.

I am also chasing some electric problems on my r50 at the moment, plan to spend tomorrow going through everything. Maybe some shared wrenching time if we both get stuck? sometimes a second set of eyes helps.

And hello everyone else, I'll try to get some pics of my new bike up in the next day or so and formally introduce myself.

Ben

VBMWMO · Post by **VBMWMO** » Mon Feb 15, 2010 2:52 pm

Hey all,

Am new to the forum - got a '63 R69S that I love and have had about a year. Have mostly been into vintage 2 strokes such as Vespas and Lambrettas, but now have this beast as well as a '65 Ducati cafe racer. Am in Oakland, CA - so would love to meet up with locals for bike nights or rides.

Anyhow - 2 questions on the R69S.

1. I'm having a hell of a time diagnosing an electrical problem. When I got the bike, all lights worked fine. Over time the course of riding over about a month, I lost turn signals, brake lights, rear light, license plate light, and headlight...the only light that remained was the neutral light. I figured the battery was low, so charged it up with a battery tender...no love...so got a new battery from Vech and now I have a brake light from the foot brake (but no handbrake), and the neutral/charge light is much brighter. I've gone through and tested the voltage regulator, battery, etc and it all looks good. I've traced the wires, nothing crimped, or damaged as far as I can tell. Electrics aren't my specialty so I hate to rip stuff out, but where should I go from here? A new wiring harness?

2. A hotly debated questions I'm sure but how much exhaust smoke is "normal"? The speedo reads 45k miles, and the bike looks it...it's in amazing shape. Unknown if it's ever been opened up and had the valve rings replaced or new piston rings, etc., but I don't think so. The oil gets quite black after as little as 500 miles or so, and I've been changing frequently...the smoke is gray, not white, not black...it's primarily out of the right exhaust pipe and really gets heavy when I wind it up, diminishes substantially when it's idling and after idling for about a minute it nearly goes away.

Any thoughts on the above?

Thanks all!
ak