After the restoration: 4800 Mile Service
Wednesday, Feb 5, 2003
It’s not quite 4800 miles, but the oil consumption is bothering me so I’m going to get started earlier. For the record the odometer reads 4558. I’ve decided to replace the rings. This after many discussions with people who know a hell of a lot more than I do about engines.
Before doing anything, though, I thought I’d check the compression. Looking through my notes I see that I did not do this after the re-build. Stupid. Anyway…
The plugs are black, but not wet. The left side is darker than the right side. The dry compression was left 135, right 165. The wet compression was just under 180 on the left side and just over 180 on the right. The third picture shows the wet measurement of the left side. So what does this mean? Probably that the rings didn’t seat on the left side.
In any case I’m waiting for a friend (with a hone) to get some time to come over before pulling the jugs. The new rings were ordered last week.
Thursday, Feb 6, 2003
The rings will be installed Sunday, but we’re going to be rushing it a bit then, so to save time I’m pulling things apart today.
First things first. The battery hasn’t been on the charger for quite a while and the water level looks a bit low, too. Actually, water on the low line in the bike translates to mid-level when sitting on a flat bench. In any case I added distilled water to bring it up to the full level and put the battery on the tender. I also replaced the quick disconnect on the positive side to get around the need for an ugly piece of electrical tape.
Before getting to heads and cylinders the carbs and pipes have to come off the bike. I don’t mind removing the muffler and pipes as it’s an excuse to really clean and polish them before putting them back on the bike. The carbs were cleaned just 1000 miles or so ago. I just put them away for now.
The left head came off easy. Before removing the cylinder I finally got around to making a cylinder removal tool: a 14 mm wrench with some bends so I can get close to the base nuts without busting knuckles.
The left cylinder bore looks OK. We’ll measure it Sunday to make sure. The rings, however, do not have that shiny “seated” look. Not surprising.
I removed the head and cylinder from the right side. The head bolts that hold the exhaust rocker were quite tight, for some reason. After removing the cylinder I tried installing the bolts and they went in easy. I wonder what was binding?
The rings on the right side were partially broken in. The top ring was beginning to seat, the others had seated. Maybe if I waited the left side would have seated, too. I’m just not that patient. I covered both pistons/case openings to keep the dirt out.
Sunday, Feb 9, 2003
After the Sunday Morning Breakfast Club breakfast and ride up CA 9 to CA 35 to Ca 92 (with an obligatory at Alice’s) Fred and I started working on the R69S. Fred recently restored a 1969 Triumph for Carl. Today he was riding his payment for that job: an R80RT. the same R80RT that I sold to Carl in ‘94. It was somehow fitting that Fred rode the RT today.
That is Fred, removing the old rings from the piston. When not taking pictures, I’m scraping the lip of carbon from the top of the cylinders with an old x-acto knife. The second picture is after carbon scraping but before honing. You can still see he original hash marks. What the picture doesn’t show too well is the glaze that is present.
We used both calipers and telescoping gauges/micrometer to measure the bore. The cylinder was bored to 2nd oversize by the previous owner, so the bore should be 73 mm. The micrometer was used to measure the piston skirt. Measurements follow.
|Left Side||Right Side|
|Skirt||72.90/72.91 mm||72.90/72.91 mm|
|Bore, top (vert)||72.99/73.00 mm||73.00/73.01 mm|
|Bore, top (horz)||72.99/73.00 mm||72.99/73.00 mm|
|Bore, bottom (vert)||72.99/73.00 mm||72.99/73.00 mm|
|Bore, bottom (horz)||72.99/73.00 mm||72.99/73.00 mm|
Fred honed the cylinders. The last picture shows a honed cylinder on the right with an unhoned cylinder in his hands. This picture best shows the glaze of the unhoned cylinder. It is shiny instead of the dull finish of the freshly honed cylinder. After honing both cylinders were washed with Simple Green and hot water then wiped and blown dry with compressed air. The cylinders start to oxidize fast! I washed one, set it down, then washed the other. When then running a paper towel through the first cylinder it came out partially rust orange.
While I was checking and adjusting ring end gap Fred started making sure the ring grooves were clean. He figured an old ring would be a good tool for the job and started to break one. It didn’t break, it bent! The new rings were all too tight and needed some filing. The spec calls for 0.25 - 0.40 mm. All rings were adjusted so the end gap was about 0.28 mm.
Fred installed the rings by hand. I didn’t know they made a tool to do that, so didn’t have one handy. This cost me two band aids – Fred has now bled for my bike. A ring compressor was used and the cylinders slid over the rings. A few drops of oil was then applied to the top and bottom of the piston skirt before the cylinder was fastened to the block. The same base gaskets were used as they cleaned up quite nicely and looked just as good as the spares I had handy.
 Sigh… I’m getting old and forgetful. A few days after the above I found my ring spreader. Yep, I own a tool that I “didn’t know they made”. I moved it to my “BMW special tools” toolbox so I’ll have a better chance of remembering it in the future.
By this time the angle of the sun makes it uncomfortable to work in the garage, so we called it a day. I’ll probably finish up tomorrow.
Monday, Feb 10, 2003
So I didn’t finish up today. That’s what happens whey you get sidetracked doing other things such as taking advantage of removed parts to do some cleaning and waxing.
I cleaned up the cylinders, blowing out any dirt and loose carbon then mounted them on the jugs, remembering to back off the valve adjustments to make things easier. I found out that the binding problem I had on the right side is the head, not the cylinder. The bolts (which are more-or-less new, and not bent) don’t go easily through the mounting holes easily on the exhaust side. I’ll query the expert to see exactly what this means. It’s not so bad that the head is unusable, but it is worrisome. I wonder if a new head is in my future?
The pistons were brought to the OT mark on both sides and the valve adjusted. I then checked the compression. With the new rings both sides read 150 PSI. I’ll check again after about 300 miles on the new rings.
The carbs were cleaned (outside) with wd40 and then installed. I also cleaned and waxed portions of the frame that are harder to get to once the pipe are back on the bike. Then it came time to put the battery back in the bike. I found out the new quick disconnect I added to the battery doesn’t match the one on the wiring harness. That was changed, too.
While looking at wiring I saw that the neutral switch wire was frayed and some electrical tape that had been used on the harness was unraveling. This prompted me to trim the tape and cover the kinks (and tape ends) with heat shrink tubing. It looks much better. It should also perform better, too. If the frayed wire started shorting to the ground wire I’d read neutral in any gear.
Battery, air cleaner, and the air intake tubes are back on the bike. A bit more cleaning, polishing, and waxing was done on bits of the frame and rear fender. The only thing left to do is clean and polish the exhaust system before mounting it. I still have to change the oil, too. Tomorrow I’m going on an all day ride with a friend, so it will have to wait until Wednesday (or later).
Wednesday, Feb 12, 2003
Yesterday a friend and I took off for a nice weekday ride (one of the advantages of being retired :-). Today was raining quite hard, so I didn’t want to back the R1150RT out of the garage to really work on the R69S.
I could still get to the right side of the bike, so I did some more polishing and cleaning. The exhaust system got a good cleaning and waxing. It needed it. The crossover tube was solid road grime. I loosely fit the right side pieces onto the bike. I’ve learned that all pieces have to be fit before tightening, and even then it seems to work best if I start at the front of the bike and work backwards.
Thursday, Feb 13, 2003
The rain stopped long enough to back the new bike out of the garage and do a bit of work on the R69S.
I finished cleaning the exhaust system and mounted it, using plenty of anti-seize where the pieces slip into each other and on the exaust port threads. Once everything was tightened I replaced the oil and lubed the things that should be lubed per the checklist. I’m going to check timing before I kick her over. I also need to check the steering per the checklist.
Friday, Feb 14, 2003
I’m glad I decided to check the timing. Those who say the points last forever are only partially correct. The contacts may last forever, but the other parts do wear.
I checked the static timing and found it off. I could not get it right. Removing the advance unit I saw that the point were as far as they could go in the direction it needed to go. Removing the points made the problem obvious. The felt had worn (picture 1) which I suspect caused the advance cam to become dry which caused the follower to wear (picture 2).
It’s not quite obvious from the picture, but the follower is quite worn, even when compared to an old set of points. I’ll see if Joe has a replacement unit, tomorrow.
Saturday, Feb 15, 2003
Joe wasn’t at the shop, but I went digging through his magneto parts collection anyway. Of the 8-12 units I looked at some were missing the points backing plate and all but 2 of the others had torn felt. The two that weren’t torn looked like they were ready to tear if I looked at them wrong. OK, I guess I’ll fix what I already have.
The local hardware store had small rivets and stick on felt; the type used to protect furniture. I grabbed the medium stuff as it looked to be about the correct thickness. I cut off an 8 mm strip and then marked the back where the rivet holes needed to be punched. A pin punch would have been the right tool, but I didn’t have one the right size. An awl did a good job, though.
The hole in the spring was too small for the 1/8 inch rivets (which were the smallest I could find) so I drilled it out to 1/8 inch (3 mm) in several steps. The felt was then stuck to the spring and riveted in place. I used the same tool used to install snaps in fabric to install the rivet.
The felt was greased, the points installed, and the engine statically timed. I kicked it over and checked the dynamic timing: it was perfect. I rode around the neighborhood… the bike feels (and sounds) fine, except the idle is too fast. I suspect that over the last 1000 miles or so I’d compensated for the bad timing as the follower wore by increasing the idle speed. I need to go on a longer ride and get the bike up to operating temperature before I touch the carbs, though. I’ll do that when the rain stops.
Sunday, Mar 2, 2003 (follow-up)
Upon returning from breakfast this morning the bike was just a few miles short of 4800 miles; about 240 miles since the new rings were installed. Scott came over to kibitz as I checked the plugs, valves, head torque, compression, and oil looking for metal bits. The plugs were OK, the valves didn’t need adjustment, the heads were re-torqued (but didn’t need it), and there were no metal bits in the oil save a very few number of particles stuck to the magnetic drain plug.
Oil consumption was minimal… perhaps a few ounces. I’ll still keep track of that. Compression is around 175 PSI on both cylinders, up from 150 just after the new rings were installed. I’d say they are seating quite nicely. The bike is running great.