After the restoration: Don't Do That!
Aug 20, 2000 (Sunday)
About 13 minutes after 7 Sunday morning the Sunday Morning Breakfast Club passed under the Ralston overpass on highway 92. I was waiting by the on-ramp. A few kicks later I’ve started the bike and pulled onto highway 92. I head down 92, through the tunnel that leads to southbound 280, and then shift into third to maintain a reasonable speed up the slight incline. I’m going maybe 62 in third which is fine as third gear doesn’t max out until 80 MPH or so.
Just after merging onto 280 a bad thing happens: the bike pops out of gear. I was on the throttle; it takes a half a second or so to get off it. Lots of RPMs. I pop the bike into 4th (always shift up in situations like this) but there’s no power. Maybe I’m going too slow. Down-shift to 3rd… 2nd… still no power. I’m maybe 2 miles from my house and well off the freeway when the bike dies.
Out comes the toolkit and the front cover is popped. The advance mechanism was still in one piece. Next I tried to kick the bike over: no compression. Not wanting to check the valve train on the side of the road I started pushing the bike back toward home. That worked fine going down 280 toward the tunnel. Coming out of the tunnel on 92 was a different story with a simple moral: don’t push bikes up hills. Call your friends, instead!
Out came the trusty mobile phone. I figured Chris Weld didn’t want to sleep in Sunday anyway. He and Pat came from Pacifica to pick me up with his bike trailer. I was home by 9:15. Thanks, Chris.
Did a compression test and found 0 compression on the left cylinder. Very low compression on the right cylinder. The valve covers come off. The exhaust adjustment on both cylinders is way off and the lock nuts are loose. The intake on both sides are dead on and still nice and tight. I’m busy for a while, but will adjust the valves this week and check the compression again. If OK I’ll fire the bike up and see if that does the trick. If still no compression or the bike doesn’t start I’ll pull the heads and see what else might be wrong.
Aug 24, 2000 (Thursday)
This is how I found the right exhaust valve. The left was similar, but with the adjustment too tight instead of too loose. In both cases the lock nuts were loose.
I attempted to adjusted the exhaust on the right cylinder, but it was quite hard as it felt like the something kept changing. Then it was over to the left cylinder. At first I thought I had it adjusted, then after some wiggling there was a 4-5 mm gap. Not good. I tried to twist the push-rod. It didn’t. Really not good. Time to take a look see at the push-rods.
The first picture is the left exhaust push-rod. If you look closely at the 2nd and third pictures you will see that the right exhaust push-rod was also slightly bent – that explained the problems I had adjusting the valve. On the plus side, both intake push-rods are fine.
If that is all that is wrong I’m in OK shape. I just wonder if I need to pull the heads and cylinders enough to check out the cam followers, too. I’m busy for the next week and a half. That will give me some time to think about the next step.
Note from 2011: I should have checked the cam followers. In 2010 I found two of them cracked, all four pitted, and my cam needing replacement. The amazing thing is that it took just under 10 years before bad things started happening.
Sep 2, 2000 (Saturday)
The last two weeks have been busy with motorcycle trips (on my K12LT) and master bath remodeling. Today I got a chance to go to Groeger’s. Joe had one used R69S push-rod. That’s not going to do the trick. I checked all four of my push-rods on his table – at least 3 of them need to be replaced.
Mark Huggett GmbH has them for 52.00 CHF each. That’s just under $30 (in 2000 dollars). $120 plus shipping will get me all four. Order placed.
Sep 19, 2000 (Tuesday)
The parts I ordered arrived yesterday. I decided to pull the heads and take a look before installing the new push-rods. It looks like there was some (minor) contact between piston and exhaust valve on the left side. The valve face looks OK, but I’ll still remove the valve and make sure it’s not bent. But it’s too hot to do anymore today – upper 90s outside and probably more in the garage. I’ll do more when it cools down.
Sep 20, 2000 (Wednesday)
I’m very glad I decided to pull the heads. Before it got too hot this morning I decided to take a closer look at one of the valves that look like it made contact with the head. I measured the valve stem as out less that .0005 inch. But the head was a different story. The valve looked bent. When checked by rotating the valve next to a square there was no doubt. I think I’ll check all four at Joe’s this coming Saturday.
Sep 26, 2000 (Tuesday)
Saturday I took the heads to Joe’s. When he chucked the exhaust valves into the valve grinder it was obvious they were bent. The intake valves were OK. I degreased and cooked the heads (cooking = ultrasonic cleaner) then blasted the carbon out of the combustion area. The valves and valve seats were both touched up, then lapped.
Today I got everything ready to install the heads, but the garage got too hot to complete the job. I did get the left head completely installed. I torqued the heads to 15 ft-lbs, made sure the end play on the rocker assemblies was gone, torqued to 20 ft-lbs, double checked the rocker assemblies, then torqued to 25 ft-lbs. The valves were adjusted, the engine rotated to ensure I adjusted the valves at the right spot, then rotated again where the valves were checked one more time. All seems OK. I’ll do the other head later this week.
Sep 27, 2000 (Wednesday)
This is not my week. The first picture shows everything ready to install the right cylinder head. The second is a close up of the piston – you can see the mark where the valve hit. The third picture shows the excessive end gap in the exhaust rocker arm assembly. I can squeeze it a bit, but there is still too much end play. This will have to get fixed before I can put things back together.
Oct 24, 2000 (Tuesday)
I’ve been busy and haven’t had a chance to work on the bike, recently. If nothing else the battery is due for some time on the charger. I used some time today to take a closer look at the rocker arm assembly and try to figure out why I was able to use it in the past. It was time well spent. I needed to make sure I was applying pressure to the end anchors, but not the pin between them. The pin did need to be in the right position, though.
The sockets distribute the clamping pressure to the anchors without touching the pin. I adjusted the pressure of the clamp for no end play, then torqued the head. The clamp was removed and end play checked. All is well.
The valves were adjusted. The adjustment lock nut was checked three times. After filling the rocker pins with oil the valve cover was installed. Mounting the carburator was next. I checked the bottom nut and screw on both carbs – glad I did, three of the four things I checked needed a little tightening.
Before putting the exhaust system back together I took a look at the side stand. I’m glad I did. The pivot screw had backed out a bit. The only way to get at it is by moving the pipes. Now’s the perfect time as the pipes haven’t been attached yet.
A liberal amount of anti-seize was applied to the exhaust threads and the pipes before torquing the exhaust nut. Also, learning from the past I cleaned and mounted the mufflers before tightening anything. Once the mufflers were installed I tightened the clamp at the rear engine mounts, then the exhaust nuts, and finally the muffler.
So I’m done, right? Well… I’ve never been one to leave well enough alone. When I ordered the push-rods I also ordered a new coil in the hopes that it will fix my hard-to-start-when-warm problem. I also got a new advance mechanism because mine was borderline.
The new advance mechanism doesn’t have the play that my old unit did. The old unit may still be usable by replacing the springs. It will be saved. I replaced the coil. Since I’m not 100% sure that it was the cause of my problems the old coil will be saved, too. When the magneto body was in my hand I noticed some wear on the points. Ok, time for new points.
I’m ready to re-time the engine, but the sun got low enough to enter the garage, making it uncomfortable to work with the heat and the glare. I’ll static time the bike tomorrow (weather permitting) and then kick it over and get a timing light on it for fine tuning. In the mean while the battery is connected to the battery tender getting a needed charge.
Oct 25, 2000 (Wednesday)
It rained this morning. About 11:00 AM the rain tapered off, letting me open the garage, back the K12LT out of the way, and work on the R69S. I adjusted the magneto rotor for optimum position at the ‘S’ mark and then gaped and moved the points using a meter (static timing). So far so good. Time for the real test.
With petcock opened, carbs tickled, the ignition on I kicked the bike over; three kicks and the bike started. A timing light showed the ‘S’ mark a bit high. A minor adjustment got it right on. And then it started raining again.
Oh well, I can wait a bit longer for the test ride. I did let the engine run a bit and noticed some smoke from the left exhaust. Hopefully it will go away within a few miles. I’m not going to worry about it, but instead will call this job done.