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schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
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I'll try to post some images of my progress. I purchased this '52 model a little over two years ago and have ridden it about 850 miles. With no knowledge of the slingers, it's time to tear into it and get things looked at. I think later models added a drain path from the head to the sump, so that will probably get done this time. I believe that a cam chain tensioner can be added or updated so I'll be looking into that.

I'll do as much as I can but will take the engine and/or tranny to Vech to have him do his magic. I did a compression test last month and has 25% leakage past the rings. Compression was about 100psi. I just rechecked the valve clearance and they were 0.15mm/0.20mm intake/exhaust, right where I set them after getting the bike. Exhaust was a tad tight, but I still got the feeler gage in there.

I'm down to removing the tranny, engine, and electrics. I'll need to think about this a little. I may build a small "stand" to hold the engine once I get it out of the frame.

  • lside.jpg
  • rside.jpg
  • electrics.jpg
  • valves.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

c.d.iesel
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VBMWMO #5514
Darien, Connecticut.
Joined: 08/08/2007
Posts: 363
R25/2

that's a pretty survivor - please give us photo updates as you go

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schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
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Disconnected Cardan Shaft

I had to look around to find out how to remove the Cardan shaft from the tranny so that I could remove the transmission. Because of the cam chain cover, the whole engine/tranny can't move forward. Once the shaft was free from the Hardy disk, then I could attack the transmission.

I removed the bell at the rear of the shaft and aligned the u-joint so that I could push in the nose of the final drive. Rear wheel was removed, too. That canted the shaft and pulled the pins out of the disk. I had seen pictures of the Hardy disk with plastic inserts along with the rubber disk. Looks like mine is just a solid rubber disk.

I rigged up some rope so I could hold the shaft back in its general location. I then could put the tire back on and roll the bike around.

  • shaftpush.jpg
  • shaftoff.jpg
  • disk.jpg
  • shafthold.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
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Transmission Coming Out

I removed the four bolts holding the transmission on. I was having trouble clearing the transmission out the right side because the clutch push rod was sticking out. I carefully moved it rearward a bit and got enough clearance to slide it out.

The front of the transmission looks pretty good...the input seal doesn't appear to be leaking. There's some oily dirt around the outside edge of the housing near the clutch...probably the rear main seal.

Just three bolts holding the clutch pack on. Is there any spring pressure holding this together? There was on my R69S and /7...I'll have to do some reading.

  • tranny1.jpg
  • tranny2.jpg
  • clutchfromrear.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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VBMWMO #7032
San Antonio, TX
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Clutch Out

Had to go out and get some long (50mm) M6x1.00 bolts to help with releasing the clutch pack tension. Swapped each clutch bolt with a long one one by one. Then backed off the nuts evently until the tension was gone.

Removed the pack. Of interest is the radial cracks in the clutch disk...an obvious replacement. It measured 7.1mm thick. I'll likely just replace all of it...just because. As I expected the oil that I was seeing is pooling at the bottom of the flywheel which means the remain seal.

I won't take out the flywheel...I think I'll let Vech do that. Next I'll work on getting the electrics off the front of the engine and removed the engine from the frame. I will probably open up the cam chain area.

  • clutchremoval1.jpg
  • clutchremoval2.jpg
  • clutchpackback.jpg
  • clutchdiskcracked.jpg
  • oilpool.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
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Prepping for Engine Removal

Weather's been kind of crummy, so only started thinking about the electrics and engine. I did remove the clutch pushrod pieces...interesting in that the forward end of the pushrod is square and fits inside the pressure plate. This is different than the /2-on pushrods...those have a taper which just touches the pressure plate.

I took pictures of the wiring (without the advance unit) and also constructed a stand to hold the engine once I pull it out. The lower rear engine bolt will fit into the slots on the 2x4s and the upper forward bolts will rest on the upright 2x4s. I'll cut some slots on the uprights when I get everything out.

  • clutchpushrod.jpg
  • electricleft.jpg
  • electricright.jpg
  • enginestand.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
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Engine Out!

Today was the day to separate the engine from the frame. First, I removed three slotted screws which allowed the whole electrics plate to come forward without removing any of the connections. I'm hoping I can just reverse this process upon assembly. I just tied it up out of the way on the frame backbone.

This exposed the rotor. I used my rotor removal tool to put some tension on the rotor. Then with the slight tap of a hammer, the rotor popped off...not quite a bang, but noticeable...I had the towel ready.

I had installed magnets in the pan a couple of years ago...they picked up some sludge. Took a little help with a floor jack to get the engine moving...then up and out the left side. My previous stand wasn't going to work...I didn't think that through! So, I just turned it on the side with the flywheel down using the studs for mounting the transmission. Once I remove the timing chain cover and the top end, it should get a bit lighter. Before I do any more disassembly, I'm going to weigh the entire assembly to get an idea of the full up weight of the engine...less the clutch pack.

  • electricsoff.jpg
  • electricsinside.jpg
  • rotoroff.jpg
  • separation.jpg
  • sludge.jpg
  • instand.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
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A little farther

Got back to it today...took off the oil pan strainer. Also pryed off the timing cover. Used a deadblow hammer and bits of wood to walk it off. Notice the amount of chain stretch. The stretch is about 6mm from a point where the chain is tight between the gears to pushed sideways. I understand that a later model tensioner (R25/3?) can be retrofitted. It will fit into the upper left part of the timing chain area.

BTW...the weight of a full-up engine is around 60 lbs. I weighed myself and then picked up the engine and found the difference.

  • oilpickup.jpg
  • timingcoveroff.jpg
  • chainstretch.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
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A Little Slowdown

I didn't get much done yesterday. I was going to try and take the rockers and heads off; hopefully get down to removing the cylinder. I turned the engine to TDC on the compression stroke and loosed up the rockers so they float freely. The intake head bolts (2) came loose easily...but the two exhaust head bolts didn't. They were very tight...I didn't do that...either the PO did or they're just corroded in place. I had to use a cheater bar to get them to turn but even still they were difficult to turn. I stopped after just one revolution of the head bolt...it wasn't really loosening up. It was taking about 15 ft-lbs to turn.

I called Vech and got some good info. Turns out the head bolts or at least the thread hole they're in on the cylinders is actually open on the threaded side of the bolt. I had no idea. I took a close look...sure enough, I can see the openings in the fins. So, I put the "head on its head" and spray in some penetrant. I'll do this for a few days, maybe try and turn the bolts to help the penetrant work in some. Maybe in a few days, I can turn these bolts out.

The arrows point to where the holes basically are.

  • boltsoak.jpg
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'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
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Almost There!

Got quite a bit done today. I did more soaking over the past week. I guess it did some good. One of the bolts coming out squeaked as I turned it. But the rockers came off. The head didn't put up too much of a fight...I was dreading that! I had real troubles with my R69S. The cylinder also came off relatively easy too. One of the base nuts was very hard to get a wrench on.

I broke a ring...oops! Well, I'm going to replace them at any rate. I haven't measured the ring gap, but I did measure the piston diameter. It's about 68.4mm...which means that the bike is already at 1st over. This tracks as the stamp on the inside of the Nural piston has a date of "2 63" so it would seem that sometime after 1963, the piston was replaced and the cylinder bored. Not sure if I've mentioned this but the bike was a police bike in Germany from about 1957 to 1970. It came to me with a little over 14000 KM on it, essentially the same mileage as when it was retired in 1970. So, I'm not sure of the actual mileage. It would appear that the police rebuilt the bike at some point. If I get the chance to get over there and go through the records, I might be able to answer some of these questions.

Ring gap was all right at the maximum, which is 0.2mm to 0.4mm. Mine were (from crank to head): oil scraper - 0.4mm; (broken); 0.38-0.39mm; 0.44-0.45mm.

Vech had told me that to get a sense of the fit of piston to cylinder, drop the piston into the cylinder without the rings and see how it falls due to gravity. When I did it, it took 1-2 seconds to go from the bottom back towards the top. That seems like a pretty good fit to me.

The only left to do is clean things up...the piston is soaking in Hyrdoseal. I'll get a little organized and pack things for a trip later this month to Vech. I'm going to hand-deliver the bits and pieces...seems safer to me!

  • rockersoff.jpg
  • head.jpg
  • piston.jpg
  • wristpin.jpg
  • pistondate.jpg
  • rodtied.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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VBMWMO #7032
San Antonio, TX
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Cleaning Up

I soaked the piston crown in Hydroseal for a week and then used a piece of wood to scrape off the build up. It reveals the Nural stamp, the Vorn symbol, and confirms that the piston is one over at 68.44mm. Not sure what the other marks are.

I also found the source of the tight head bolts holding down the exhaust rocker blocks. In the picture you can see the shiny parts on the one head bolt, just under the rocker block. It seems that the tower that the bolt went through in the head must have mushroomed out and constricted the bolt from turning.

In examining the cylinder bore, the cross hatching is still visible. This indicates there has been little wear since the cylinder was oversized. That probably suggests that I can get away with a simple clean up, Bore Tech treatment, and rering. I'll let Vech make the final determination.

  • pistontop.jpg
  • exhaustrocker.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

etienne.burgade
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VBMWMO #8172
Near Paris (France)
Joined: 11/28/2011
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chain tensioner

Kurt,
On the R25/2 I rebuilt, I have had a new R 25/2 chain tensioner. Easy to find.
Thanks for your pictures and descriptions, very useful.
Etienne

  • before_chain_tensionner.jpg
  • chain_tensionner.jpg
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Etienne
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schrader7032
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San Antonio, TX
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Etienne - Yes that is the

Etienne -

Yes that is the picture of the tensioner that I'll get installed. I hope it will improve the way the bike runs. Seems to me at 6mm side play, that can change the valve timing a little bit.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

etienne.burgade
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VBMWMO #8172
Near Paris (France)
Joined: 11/28/2011
Posts: 65
tensioner

Kurt, I am maybe wrong but I don't think that BMW change anything in the timing when they put it on the 25/3 as an improvement.
I think it will just be better for your 25/2.
I am following your good work, thanks to share.
Etienne

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schrader7032
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San Antonio, TX
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Etienne - I wasn't suggesting

Etienne -

I wasn't suggesting that the timing numbers changed from one model to the other. I was saying that if the chain stretches, the camshaft and crankshaft can rotate a small amount with respect to each other due to the lengthening of the chain and thus the timing of the valve opening and closing in relation to the piston will also change. I don't have any experience with how much stretch is takes to really make a noticeable difference.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

c.d.iesel
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Darien, Connecticut.
Joined: 08/08/2007
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single cylinder timing chain and cam timing

yes - the slack in timing chain will result in slightly retarded cam timing - not ideal

then add any wear in an old chain - stretch - and more retard

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VBMWMO#5514- '64 R27 15K #383851 - '86 R65 22K #6128390 - '13 Fiat ABARTH #DT600282 - '11 FORD TRANSIT Connect #058971 - Retired m/c road racer (1971-2000) - Former M-Benz Star Tech 19 years, BMW Master Tech (cars) - Certified BMW (bike) Tech. Presently BMW Car Sales

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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
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In Vech's Hands!

I put all the engine parts in my car and drove to Vech's place in Sturgis, Mississippi, to drop off for overhaul. A couple of hotel nights, half a dozen tanks of gas, a few bad meals...knowing everything arrived save and sound...priceless!

I'm in the queue with several other engines ahead of me. Vech said he'd send the heads off the Memphis Motorwerks for overhaul...he'll convert to rotating valves as the current ones were non-rotating. The cylinder and piston will go to Bore-Tech for carbon impregnation of the bore. He'll have the crank inspected by Chris Chambers to see if it is still OK. We've talked about the new cam chain tensioner as well as drilling the extra piston skirt oiling hole. The flywheel has no markings on it except for the TDC mark. I crudely marked with a sharpie the full advance point that I figured out using a degree-wheel I fashion. Vech will transfer static and full-advance marks to the flywheel. The breather pipe has been missing from this engine...he'll install that.

While the top end has been overhauled once in its life, we don't know about the bottom end. I'll be interested in finding out about the state of the slingers...that might be me a sense of how many miles are on this engine.

Here's a picture of me at the street in front of his shop. If you haven't been there, you should stop in. Vech has a great museum. He showed me his latest project...a 1932 R4 Series 1 he's putting together...incredible!

  • atvechs.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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San Antonio, TX
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Engine is apart

I got an update from Vech's shop today. They took the bottom end apart. I asked a bit more about what he found:

- His estimate is that someone had been inside in the past; the slinger was fairly empty.
- Rod bearings are OK but the main bearings were black and nasty and might have been in there since 1952. His thought is that maybe they took it apart for the slinger but reused the main bearings. They will be replaced.
- No crank rebuild is necessary.

Since I had pulled the top end apart, the head and cylinder were sent off a couple of weeks ago.

  • teardown1.jpg
  • teardown2.jpg
  • teardown3.jpg
  • teardown4.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
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Making Progress!

More work was done...the crank with bearings and camshaft were installed. The new timing chain is in, along with a chain tensioner. The 1952 model didn't have one, so this is a retrofit from a later model. Also, my flywheel only had an OT mark on it. I asked if they could add the S and F-marks. They laid an R25/3 flywheel up to mine and transfered the marks. They look pretty nice!

  • timing_chain.jpg
  • flywheel_timing_marks.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
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Cylinder is back

Got a call from Benchmark Works. The cylinder and piston are back from Bore-Tech. Both were within spec so no overbore was needed. They applied the carbide treatment to the cylinder wall.

The piston is a 4-ring type but normal piston sets are only 3 rings. Rather than buy another whole ring set, one of the remaining compression rings will be reused. An initial fit in the bore showed one to be a nice fit. Looks like the carbide treatment decreased the bore dimension a slight amount.

Just waiting on the top end!!

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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VBMWMO #7032
San Antonio, TX
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Engine's Together

Richard at Benchmark Works says the engine is together. Apparently one or more of the inner valve springs were collapsed...about 6mm too short...so those were replaced. The outer springs seemed fine so those were reused. On previous posts, I had issues with the head bolts taking quite a bit to get out. Richard said after tapping the threads in the cylinders, the bolts went in basically hand threaded so that looks to be OK.

I'm tied up at work and other committments so can't go get it... Crying Hopefully later next month I can get back out there and pick it all up...and open my wallet!!

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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San Antonio, TX
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She's Back!

I drove back to Vech's Thursday and picked up the assembled engine on Friday morning, then dashed back home. Everything looks good! I discussed steps for break-in - starting, engine speeds, retorque/valves after about 75-100 miles, changing oil, etc. I also bought a deep sump in order to increase the oil volume since there is so little in the sump to start with. I think this takes me to about 1.75 liters instead of the 1.25 liters for stock. The kit comes with all the bolts and gaskets plus an extension to the pickup screen.

Check the close up photo of the head...the next owner (if there's every one!) will wonder why BMW stamped someone's name into the head. That might start the rumor that the person who assembled the head at the factory did that to "sign" their work! I'm sure it was Memphis Motorwerks who did it as part of their process to overhaul the head.

Now, where did I put that frame!!

  • engfront.jpg
  • engside.jpg
  • valves.jpg
  • namestamp.jpg
  • deepsump.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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San Antonio, TX
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Engine's In!

I plied a friend with some drink (OK, it was just a soda!) to come over and give me a hand. We got the engine in the frame. Looks good!! Before starting that, I figured I'd to a couple of things.

First, I kept wondering why the foot pegs were tilted up at the tips...it really felt weird riding. I wondered if the PO maybe put them on the wrong side. After some experimentation, I realized that switching them would get them more parallel with the ground. You can see the right peg before and after.

Next I thought assembling the clutch pack would be easier out of the bike sitting vertical. I bought new clutch springs. Look at the picture of the sets of springs...quiz...which springs are the sacked ones! Youwzer!! The other picture shows the clutch pack going together with the long screws...I turned the nuts down evenly to seat the clutch pack against the springs.

Finally, the engine went into the frame with my friend's help...thanks, Jay!! The picture also shows the deep sump that I bought from Vech. I increases my oil supply from a little over a quart to about 1.75 quarts. That should help quite a bit keeping things cooler.

Next is the tranny and finally the electrics...and a dozen other smaller things as well.

  • pegbefore.jpg
  • pegafter.jpg
  • clutchsprings.jpg
  • clutchpack.jpg
  • enginewithsump.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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VBMWMO #7032
San Antonio, TX
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Clutch In

Today, I got the clutch pack secured. At first, I tried just removing one of the three long bolts but when I did that, the whole pack began to push out of plane because there are only three bolts holding it in. So, I had to find a piece of aluminum angle with holes drilled to match the transmission studs. With the angle in place and pushing a spacer against the pressure plate, I could remove one of the screws. I installed the new bolt with blue loctite using a nut-driver screwdriver. The torque is only 5-7 ft-lbs...I talked to Vech and they said to just get it tight. This is the way I tighten the oil pan bolts...just get them to a nice even tightness.

I also cleaned up the transmission...that will probably go in in the next day or so.

  • clutchtemp.jpg
  • clutchbrace.jpg
  • clutchin.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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San Antonio, TX
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Transmission and Generator In

Seemed like a good day to take some vacation and get some work done on the bike. I installed the transmission last weekend, but couldn't get the clutch pushrod to seat completely...it's a one-piece rod with a square end that mates to a square hole in the pressure plate. But it didn't find "home" when the transmission slid home and consequently, the clutch parts (race, bearing, and thrust piston) didn't go deep enough into the transmission cavity. One suggestion was to slide the transmission back and use a long pair of pliers to help the rod along. But I had already worked hard to get the tranny in and the final drive and Hardy disc in place.

I got the suggestion to build a little tool that clamped to the rear of the pushrod which would give me the leverage to manipulate the rod. A small drawing was provided and I built the tool...with some adjustments for my bike. I clamped in place and within a minute, I was able to properly locate the rod. Then I installed the clutch parts at the back and eventually hooked up the clutch lever. Clutch works great.

I also finished off the rear wheel and fender connections and the Cardan shaft and Hardy disc are in place. I was also able to feed in the three screws that hold the generator/ignition housing around the rotor. I still need to hook up all of the ground wires, etc. and install the advance mechanism.

  • rodtool.jpg
  • rodtoolin.jpg
  • clutchparts.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

miller6997
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Brilliant!

That's a really neat work-around!

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'67 R69S
'13 F800GT

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San Antonio, TX
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A little more progress

Got all the wiring connected up. I'll have to check the timing at some point...it was running OK when I disassembled the bike...I was able to just completely lift off the generator/points/etc. and I just put it back in the same place. But with the new timing chain and an upgrade to include a tensioner, things might be different.

I installed the oil pickup with extender to accomodate the deep oil pan. Note that I put the rare earth magnets on top of the oil pickup since the pan is aluminum. Got the pan installed, too...I just hope I remember to put oil in it!!

I've got an issue with the clutch lever arm adjuster at the back of the transmission. There's very little room between the lever arm and the frame downtube. I can't get a standard bolt with jam nut in there, so I'm going to have a piece of threaded rod cut to fit. The forward end will be turned and flattened while the back side will have flats put on it so I can stablize it while tightening a jam nut. Using a standard hex head bolt wastes space that I could use for threads. I'll post how that works when I get it installed.

  • electrics.jpg
  • oilpickup.jpg
  • oilpan.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
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Light at the end of the tunnel!

Hope it's not a train! Just about there... I had to make my own clutch lever arm adjuster since the bolts I'd been using were too short and didn't have enough room to include a jam nut...it's a puzzle to get the whole mechanism on and still clear the frame. So I took a 40mm bolt and cut it down to a little over 23mm. On the front end, I filed it flat...this is the end that pushes on the clutch pushrod. On the aft end, I filed opposing flats about 6mm across. This lets me get in with a thin open end wrench while I turn the jam nut down against the lever arm. There's just barely enough clearance on the aft end with the down tube of the frame.

Got the battery tray and battery in...will connect it later. Put the carb on. I switched from the brass float to a plastic float (11gr) from Vech. Note this carb is a "bottom feeder" so the rod through the center of the float had to be carefully pushed out the bottom of the carb, letting me get the float out of the chamber...then I reversed the process, letting the new float snap into the groove on the rod.

Lastly, got the muffler positioned and tighted all engine mount bolts down. Oh, and I remembered to put oil in the bike!! Will be checking for leaks. The book spec is for 1.25 liters (about 1.32 quarts) and I ended up putting in about 1.45 liters (or about 1.5 quarts). I thought I'd get more with the deep sump, but will recheck the first run.

Last things to do include checking timing, puting the valve covers and the tank on. I'll need to spend quality time going over all of the things I touched to be sure that they're tight!

  • clutchadjuster.jpg
  • clutchleverin.jpg
  • carbfloat.jpg
  • exhaustcarbbattery.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
Joined: 10/27/2006
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All Over But the Kicking!

Finally got everything together. Had a bit of a puzzle with the deep sump. After filling the bike with oil, I noticed oil under the bike. I cleaned everything up and baby-powdered the bottom of the pan. After about 5 minutes, there was a drop of oil on the bottom fin right in the middle of the pan. I repeated the process and confirmed that it was leaking. I sent it back to Vech but he tried a different experiment (parts washer fluid rather than oil) but it didn't leak on him. He returned the pan. But, when I put it on the second time, same thing. Vech replaced the pan...it's an aluminum casting...and now there are no leaks. The picture isn't that great, but you can see the droplet.

I went over all bolts...things seem fine. I tried to check the timing by measuring the change in resistance across the points but realized that I had to removed the ground wire from the condensor...no easy task. I decided to measure the voltage across the points with the ignition on and watch for the change in voltage. I must have hooked up the meter on the wrong side because I saw no voltage changes. But I did hear snaps of spark which was the points opening and the spark that happens just at opening. I checked the static timing at the S-mark and also at the F-mark and it was close enough for now. Essentially where it was when I last ran the bike.

So, after a check of air in the tires, I'll try it tomorrow morning. I live near a freeway and can use the access road for about a mile in each direction with a signal light in the middle. If I need to, I can duck into the turnaround if the light is red. I want to keep the engine running up and down the revs...by doing it early in the morning, I won't be in anyone's way.

  • wet1-1stlr.jpg
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  • right.jpg
  • rightqtr.jpg
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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San Antonio, TX
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She Started!!

But not without some effort. After much kicking, there was no hint of trying to start. I checked fuel flow and made sure there was fuel in the bowl. I took an old spark plug and strapped it to the engine and kicked it...I had spark. Still no joy! I took out the plug and did the spark check as well...still OK. I kicked a few times without the plug and could see/smell fumes so I figured it was getting gas. By kicking, I probably helped clear any flooded situation.

Finally, she rumbled and I coaxed the RPMs up. I held RPMs highish for about 30 seconds, then went for a ride. All the time I varied the speed and gears, accelerating and decelerating. I went about 15 miles and decided to bring it home.

Things to look into: 1) it was getting harder to shift with some grinding of gears...the clutch hand lever had too much play so probably not getting good disengagment; 2) small exhaust leak at the header; 3) some backfiring upon accel/decel nearing the end...probably need to check timing much closer.

I'll probably drop this oil and replace, then ride for another 70-80 miles. I'll change oil again and check the valves. I'll try to get to 300-400 miles and change oil and check valves one more time. Hopefully she'll be broken in by then.

So, on to my next project...getting a topend done on my /7. I'm sure glad I have other bikes to ride!

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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Sounds like some fine tuning

Sounds like some fine tuning and you will be on your way. I really like the green color. Thanks for taking the time to share it.

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backfiring upon accel/decel

Kurt
I've been enjoying reading about the progress of your bike. The backfiring may go away when you tighten the exhaust nut.
Dave

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Dave Reina
Brooklyn, NY

schrader7032
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San Antonio, TX
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Dave - Exactly...I only put

Dave -

Exactly...I only put it on hand tight...I have this "aversion" to cranking down on that...I did use a fair amount of anti-seize. I could just wait for the carbon to build up at the hole and let it fix itself!! Laughing

The clutch freeplay probably makes sense...it's a new disk so it's bound to wear some...I just have to keep up with until it beds in.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

schrader7032
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Second break-in run

Second break-in run today...didn't go so well. At Wits End Only made about 5 miles when I began to feel some surging or slight loss of power then back up to speed. It got to a point where I just couldn't keep accelerating and was barely holding speed...almost like someone was reaching out and holding me back. I came home and revved the bike in the driveway...it seemed OK but there was some smoke seeming to come from the exhaust nut; also some oil drips from the tip of the breather pipe.

I'll have to check the timing and possibly the valves. I thought I'd go 75-100 miles before checking the valves, but maybe I need to retorque and reset the valves.

Update...checked the timing; I could hear the snap or arc when the points opened and the S-mark was pretty near the center of the window...probably still need to check with a timing light. The exhaust valve clearance had closed from 0.20mm to 0.15mm, so I reset it. The intake valve clearance was a tight 0.15mm so I opened it just a bit. I maybe have to remove the carb and ensure that the float is working correctly.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

R26
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Posts: 58
Bummer....good thing you made

Bummer....good thing you made it home. Hopefully it's something easy to correct.

808Airhead
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Joined: 08/05/2009
Posts: 512
Check your timing again,and

Check your timing again,and check for plugged carb jets/filter/petcock screen/gas cap vent...check all the cheap stuff first and don't overheat that brand new motor with a lean afr or bad timing.
New motors can be tight and make more heat than normal,but hopefully you are only feeling a fuel starvation symptoms
and not mechanical overheating/seizure.
First thing to check is the plug,even after 5 miles it should have a little color. On my first ride after getting my R69s together, I had that intermittent loss of power and it was the gas cap not venting!
Good luck Kurt.....Costco also sells affordable borescopes now ($150.00-ish)so you can see the the bore if you are curious how the cylinder looks. Also if you see liquid coming out of the exhaust and smoke,you may be having a flooding issue(?) I tried those floats and it made my mixture change at idle.

schrader7032
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San Antonio, TX
Joined: 10/27/2006
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Got around to checking

Got around to checking compression and timing. First, when cold, the compression was around 100 psi...throttle held wide open. I started the bike and found that it was too advanced. No S-mark at idle and when advancing the throttle, the F-mark came into the window and just about disappeared out the top. Readjusted the timing...now spot on at idle and at full advance.

Went for 12-13 KM ride...no problems, bike felt fine. Came back and rechecked the compression...best I could do was 105 psi. My rough calcs say that should be pretty good (I'm going by 1.0 over compression ratio times 14.7). Could be my technique, but I think there's no concern there.

I checked my records on the carb. I'm running the 110 main jet and the needle is in the 3rd position from the top...this seems to be what I can find in the specs. I wonder if that's too rich and might be causing my fluffy sooty carbs...could have been the too advanced setting.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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