ALL DONE!

Everything is back together! Took it out for a test drive last night and everything seems to be working properly. Aside from one burnt out headlight, I shouldn't have to do anything else to it for a while. I guess this blog is finished now. If there are any further repairs or upgrades I'll be sure to post them. Thanks for following. And thank you Eric for your advice and expertise throughout this project. It's always nice having a second opinion.

I should also add a couple of notes about some issues mentioned earlier. The smoky exhaust is gone now and the issue with the timing being slightly off hasn't seemed to affect anything. So it looks like we're good to go!

Brake Cleaning & Adjusting (+ Fluid Replacement)

All cleaned up

Master cylinder components

Since I couldn't get the backing plate off to replace the wheel bearings (without resorting to serious violence), I had to remove the brake lines and drain the system. No big deal, because I wanted to replace the fluid anyway. Once everything was cleaned and reinstalled, bleeding the air out of the lines took way longer than I thought it should. It didn't seem to build any pressure to push the air out, and I thought the master cylinder was shot. I took it apart and everything looked OK, so I put it back together and kept trying. After pumping the master cylinder with a screwdriver and cracking the bleed screws over and over and over, air slowly started to escape. It seemed like the master cylinder needed some back pressure in the lines before it would start pulling the new fluid in. It all worked in the end, (with lots and lots of pumping). Everything is back together and the adjusters are set.

New Front Wheel Bearings & Seals

Old bearings. There is an inner and an outer with a spacer in between. I drove the old bearings out with a punch up against the inner race. I couldn't get the backing plate off (rust/loctite?), so I had to work around it.

Old bearings/seals/spacer

New inner & seal. I used a press and a piece of round bar to install them.

New outer & seal

Before reinstalling everything

More Issues... Solved!

I guess I jumped to conclusions. 

After letting the engine run for a while, (probably 15 minutes), the smoky exhaust pretty much went away. I did a compression test once everything was warm and came up with good results. 135 psi. So I guess everything is OK. The smoke could have been a result of the top end rebuild. I thought I had already ran the engine enough to burn off the oil, but maybe not. I suppose the smoky exhaust could also just be caused by the cold temperatures (-5C in my garage) and the cylinder/piston having a loose fit until everything gets really warm. I'll start it up again on a cold day and see how smoky it is.

I also checked out the reverse issue more closely and found that it was just a sticky cable. The spring wasn't returning the lever all the way back, so the reverse switch thought that the knob was still turned. The cable is lubed up and now it works perfectly. Now you have to hold the knob while shifting down to get into reverse. You still don't have to apply the brakes, but that may not have been the original procedure either. (?)

Now the only things left to fix are the front wheel bearings and brakes.

More Issues

Well... now that it runs, a few more issues have popped up...

It's pretty smoky once it gets warm. I will do a compression test soon which should determine if it needs new rings. If the compression is OK, then I guess it could be valve seals. (?)

I also noticed that I can shift into reverse without pressing the rear brakes or turning the reverse knob. I haven't investigated the cause yet. It's probably something that should be fixed to avoid accidentally popping into reverse while moving forward and blowing up the transmission.

It's ALIVE!!!

IT RUNS!! After all that, it was the pickup coil causing the grief, even though the tests showed that it was OK. (??)

New stator and pickup coil. (Comes together in the same wiring harness).

Old stator & coils.

New CDI. (Now I have a spare).

New ignition coil. (Also have a spare now).

Putting the side cover back on.

New Parts - An expensive way to troubleshoot

- Tried a new CDI. ($220) - Nope. Still have intermittent spark. No returns. OUCH!
- Tried a new ignition coil. ($40) - Nope.
- Ordered a new stator/pickup coil. ($100) - Arrived in the mail today. I'm going to try it tonight.

As for total spending on the Big Bear, I'm still below what I would be able to sell it for (running), so I'm not too concerned. Let's just hope not too many other problems show up!

If the new stator/pickup coil doesn't solve the problem, then I guess the only thing left is to rip apart the wiring harness, which I really don't want to do.

In the back of my mind, I'm still a little concerned about the timing being off slightly. But I guess I'll worry about that after we get it running. 

Testing

Well... we've tested all of the components in the ignition system individually, and everything checks out fine:

1.) Spark plug - new, gap set (0.6~0.7mm)
2.) Boot - (10k ohms)

3.) Primary coil - (0.36~0.48 ohms) - checked between orange wire lead and coil base
4.) Secondary coil - (5.44~7.36k ohms) - checked between orange wire lead and spark plug wire
5.) Engine stop switch - continuity between B/W & B
6.) Main switch - continuity between B/W & B
7.) Pickup coil - (459~561 ohms) - checked between W/G & W/R
8.) Source coil - (270~330 ohms) - checked between B & G
9.) Peak voltage output of both pickup coil and source coil - no specs but they seemed OK
10.) Wiring connections - checked for continuity end to end and between ground on all wires related to the ignition system. Everything looks OK.

Soooo.... now what? 

Electrical Problem

Something on here is causing weak & intermittent spark.

Valve Clearance Set

Valve clearance adjusted. Intake side was OK. Exhaust side was too tight. Opened up to 0.007".

Flywheel Key Not Broken

I did find a chunk of the aluminum boss that broke off from the idler gear. Still worth pulling the flywheel.

Homemade Puller. Thanks Eric.

Key wasn't sheared off like I suspected. Now I'm stumped as to why the timing is slightly off. Oh well, we'll see if it runs and then worry about it.

 New stainless studs for the exhaust, cut from M6 SS threaded rod. New exhaust gasket too.

New gaskets and wire brushed the carbon out.

Timing Off Slightly

With the "T" lined up in the hole on the cover, the line on the cam chain sprocket won't line up with the upper mark. It's either on one side or the other. Somehow the timing is off just a bit. As far as I can tell, the flywheel must not be in the correct position, which means that the key must be broken. I guess I will pull the flywheel and confirm.