Winter Project-V1.0-or why every 60 year old bike is a pig in a poke

[DIS295]

This narrative is about the ’64 R69S I purchased in July from a seller(not the PO) in CA. The bike’s mileage was unknown. Visually it was about a 10’ bike. Up close the frame looked like it had lost a chain fight. Engine looked good and the tank and fenders were decent. I’ve never been able to figure out why there are so many large chips on the frame & forks. There are matching holes in the rear down tubes near the battery box; brackets for panniers?

Even though the seller hadrecently had the oils changed, I changed them all again, since it appeared from a receipt that the gearbox had GL5 in it. I used non hypoid/non GL5 in the trans, and fresh, hi zinc oil everywhere else.
After some fettling I had a bike that looked nice()from 10’), started and ran well. I was content. I rode it for about 1000 miles.

On a hot day in September I had parked it on the side stand after riding it to a friend’s house. When I returned to start it there was a larger than acceptable puddle of oil underneath. I immediately ascertained that it was gear oil coming from multiple orifices. Back in the shop I replaced the shift and k/s seals. This cut the loss about in half. I was trying to persuade myself that the remaining leak(g/b input shaft?) was tolerable, but was dissuaded from that fantasy on a long uphill when the clutch started to slip at about 60. My winter shop schedule was filling up rapidly. My NSU is already apart awaiting a new camshaft, so it went to the outer shed for the time being. The other fantasy I had, was that the original PO must surely have had the slingers cleaned, but since he was no longer alive, there was no way to tell.

After perusing websites and my newly acquired Barrington book, I decided to take the trans out to replace the input shaft seal(and clutch plate) and also perform some top end investigation, along with gathering up my psyche to open up the bottom end. Naturally a friend comes by and says, well, if you’re taking all that out, why not blast the frame & repaint? Ughh! Even tho he volunteered to do it, I’m still resisting. I want to ride in April.

So this week I stripped the tank/seat off, removed carbs etc. And pulled the top ends/cylinders off. Initially I was glad to see minimal wear in the cylinders, even tho the pistons were a bit on the loose side. I figure a standard amount of coating on the skirts from Swain and new rings/hone. Will work great.

While looking into the crankcase I notice a piece of metal about 3/16” square with a dab of orange paint on it, sitting on the screen. Near it is a chip of orange paint. I remove both and am thinking, I’ve seen orange paint today, and wandered over to the four tappets on the table. Yep it’s a piece of tappet, but not of any of these four tappets. Hmm, a prior tappet failed and the PO or mechanic replaced the tappet and took most of the pieces out of the engine. Hmm. That explains the fact that there are three four slot tappets, and one two slot tappet. I tried to imagine how a tappet would fail and not FU the bushing, so I went and looked. I was correct, except it looks like he had two failures, since two bushing are gouged and loose. My newly acquired 20 mm go/nogo guage(aka wrist pin) confirmed that the Mechanic decided that extra clearance and extra steel bits are OK. One last thing, critical inspection of the old tappets revealed at least one of the four slot tappets has a crack.
The plan now is to source 3 2 slot tappets and make two tappet bushings to install when I have the crank out and find the pristine slingers. April is getting closer every day….

[mcsherry1328]

After reading your missive and pondering it for several days and seeing know one has replied I thought I would share my thoughts.
It seems your bike is complete and that’s critical.
You are certainly doing the right steps by thoroughly inspecting engine internals. Since you haven’t got the accurate history on the bike and know that the engine has had issues with lifters for sure.
The Barrington manual is a real necessity regardless what you do with your bike.
So you have to decide if you want to do a restoration or build a dependable daily rider.
Regardless, I would assume that the slingers need service.
This is a significant project and requires special tools and good mechanical aptitude.
I would forget having a specific completion date.
A full restoration can take a few years and be pricey even if you do most of the work.
When completed you will have a nice classic vintage and very desirable
motorcycle.

[DIS295]

Thank you for your thoughts.

As a comparison, I have an NSU for MotoGiro events in the northeast. It has been totally rebuilt, every bearing, seal, gasket, bushing, etc. But I've done nothing to the exterior. Calling it patina is generous, but that's how I like it. Original pale blue paint visible through candy-apple red and black rattle can paint jobs has most people wondering whether if it will finish a stage, much less a whole event. I've run multiple moto-giros with it with one class win.

This R69S deserves more, and it will get it, just how much more is the question. My optimism has me holding firm to my April target. How I manage scope and my speed of execution is my challenge. The unknown is what I find as I delve deeper. I may provide updates if anything interesting happens.

[Slash2rider]

If you don't plan to stripdown gearbox yet don't turn it around much when replacing seals ,some of the metal shavings may find the way into bearings,it's BMW there is some glitter in almost every one.You may find oversized cam followers if still available.

[DIS295]

I have a process for removing seals that doesn't put anything at risk, EXCEPT that the trans input seal is installed the reverse of the other seals. Looks like I have split the trans case to push the seal out from the inside. Was hoping to not go into the trans, as it is working fine.

[Slash2rider]

If yours process don't work wood screws don't care what side seal is in.