After a very eventful couple of days, I finally have some real progress to report.
Lets begin with Saturday:
In the evening, I had a couple of hours to work on the bike. Since, the day before, I install the engine in the frame, I was hoping to start wrapping things up a bit. I began with the wiring harness and routed everything the way it was before I took it apart. At first I worked from memory, which is normally a good thing; however, as it has been weeks since I took it apart, my memory failed me. Fortunately, I took some digital pictures of the wiring harness before I took it apart, and after a quick refreshment course, all went smoothly.
Then, since I had the tank, radiators, and everything else still off, I decided to check valve clearances before proceeding further. I took the valve cover off, and removed the magneto cover (this is normally not necessary, but I wanted to replace the gasket). After I replaced the gasket with a new one, reinforced with silicone on both sides, I took off the two caps necessary to rotate the engine (via magneto bolt) and to check timing marks on flywheel.
Rotating the engine counterclockwise, I watched for the intake (rear) valves to complete a full operation, then move the flywheel further 1/3 of a turn to align the T mark on flywheel with a the notch in the observation window. The valves were slightly off. Kawasaki provides valve clearance of .20mm - .24mm for both intake and exhaust valves. My exhaust valves were in excess of .25mm, while the intake valves were less than .20mm. Using a feeler gauge purchased on Friday for this very reason, I set the valves at .23mm each, and rotated the engine two full turns. I then rechecked the clearances. Intake valves were closed again, less than .20mm, while exhaust valves stayed as set. I readjusted the intake valves, rotated engine two additional turns, and rechecked them again. This time, all valves remained at .23mm. Perfect! Just as I was about to pull the feeler gauge out from underneath the last rocker, I heard something dropping into the engine. Not a sound one wants to hear when working on an open top-end. Since I had no tools laying around, I was puzzled at first. And then I spotted it – the nut, which held my feeler gauges together, came loose and dropped into the engine, on the side of the timing chain. I tried locating it with a flashlight, but to no prevail. Since, by then, it was almost 10:30 at night, I gave up on the idea of locating it, and went upstairs. Needless to say, I did not have anything nice to say about what happened.
Sunday morning:
After numerous failed attempts to locate the missing nut, I was left with only one thing to do – the nut had to come out. Leaving a metal piece in an engine that spins six thousand times per minute is not only a bad idea, but it is also a dangerous thing to do. Should the nut get picked up by flowing oil, it could not only cause a substantial damage to the engine, but it could also cause the rear wheel to lock up at high speed due to damage to gears.
I first attempted the easy thing – flipping the bike upside down, in hopes that gravity will do its part and the nut will drop out the way it fell in. While picking up a 200-pound bike and flipping it around is not an easy task, it is easier than the alternative – splitting the engine. I laid the bike on its side, grabbed the wheels, and pushed it upwards. In no time the bike stood on the subframe and handlebars. But no matter how hard I shook or how many times I tapped on the engine, the nut did not fall out.
Frustrated, I opted for option two – looking for it inside the engine.
Since the KLR 250 has a magnetic rotor, I assumed the nut could be near the magneto (which is located right underneath the cam chain). I took the magneto cover off (breaking the new, beautiful gasket I installed only a few hours earlier), and looked in there. Nothing. Next, off came the magneto flywheel. This was not an easy task, as the flywheel has to be held in place to remove the bolt that holds it on its shaft, and the bolt itself is torqued at 87 ft/lbs. Not owning the proper gear for this, I used a large socket wrench and an adjustable wrench. Yes, it worked. As soon as the flywheel came off, I spotted the nut laying in some sludge right behind it. Greatly relieved, I used the opening to inspect gears and timing chain. This is when I noticed something red between the timing chain and the cam chain.
At first I though it was some red silicone the previous owner used to reinforce his home-fixed stripped drain plug. I tried pulling it out with a gasket pick, and this is when I discovered that it was not silicone, but something rather hard. Twenty minutes of pulling, pushing, and wiggling, it finally dropped down between the gears, from where I was able to pick it up. Nope, it wasn’t silicone, it was ... a screwdriver!
I have no idea of how long it’s been in there, or who left it in there. However, I’m glad I found it, as this would most certainly cause much bigger problems than the little nut I dropped it.
From this point on, it was cleaning things off and installing the magneto cover back on (reused the paper gasket, but cleaned off silicone and applied new silicone on contact surfaces).
Initially, I planned on finishing the bike this weekend, but the lost nut “episode” set me back by a few hours, and there was no way I could have finished everything else.
This, however, did not stop me from making some serious progress.
To be continued...