Thank you @Prospect! I think I enjoy sharing progress on this forum as much as the restoration itself sometimes. Glad you are enjoying it. There will be much more to come. I see in your signature you have a ’75 Gl1000. I had one as well! I sold it to buy this cb750 back. Pretty neat bikes.
Tonight it was time to give the bike a test drive after yesterday’s ignition work. I fired it up and was disappointed to see that the pipe was blowing smoke again. Whenever I’d blip the throttle a puff of smoke would follow. It idled nice and clean but with some gas it would blow white/blue smoke. I let it run for a few minutes this way.
I wondered if maybe the pipes were just full of junk from running poorly so long. Maybe it needed a good hard ride before making any final judgements. Before heading out, I checked the oil. It was an inch over the full mark…
Well what the heck, that could produce some smoke. I had checked the oil after buying the bike, before I fired it up, but never actually checked the level. It was more of a “yup, there's oil in there” kinda check. Not knowing if it had been overfilled, or if gas had leaked into the crankcase from leaking floats (remember, I did have gas in the overflow tubes when I first tried to start it) I decided to do an oil change.
This was the first of a comedy of errors for the evening. I removed the filter housing as I was sure I had a filter kicking around, but turns out I did not. No big deal, I’ll just change the oil and reuse the filter. After adding 3L of oil, I fired up the bike and oil leaked rapidly from the filter housing. It was dripping before, but this was much worse. I have a few spare housing o-rings laying around and had to try three different ones until the leak finally stopped. It seems there is a tiny scratch on the sealing face that is letting oil past. I put a dab of Hondabond on it and that seemed to do the trick.
With the bike running, I headed out on my ride. It was about 10:30pm and dark out. 10km in, I stopped for gas. The bike was running GREAT. The stock, richer needle position was a huge improvement. The bike accelerates much better, and also doesn’t pop nearly as much when closing the throttle. I have the IMS at 1-1/8 but I think an even 1 turn might be perfect.
At the gas station, I couldn’t see any smoke from the pipe when blipping the throttle. Could it be? Success already? I filled up with premium and hit the highway.
Then my headlight died…
I pulled over but could not get the headlight to light up again. Bummed out, I turned around and carefully rode back into the city and home with no light, disappointed I couldn’t really give it the beans yet. Once back in my garage, I could again clearly see smoke puffing whenever I blipped the gas. Doesn't seem to have changed at all.
I pulled the 1 and 4 plug. They look almost identical to the plugs I pulled out when I bought it. Black and either very rich, or burning oil. I also noticed the threads of the worst plug was oily. Not looking good for my pistons is it! The worst plug is #1. With the piston at the bottom, I tried to peer into the cylinder. I can see some scratching, but I think it’s just the cross hatching. I need to borrow a borescope.
This is the same plug. White on one side. Black on the other. But if a zebra complex. Not sure what’s up with that?
Ok, back to the headlight. I traced the wiring back from the headlight until the fuse box. Just look at the mess behind the headlight, so many splices, electrical tape, even a spider jumped out of the mess! The fuse box is rough looking as well, like everything else.
I found the 7A fuse that powers the headlight. I started to pull it out and the light came on! The clips were very corroded. And I also found a 14A fuse when it should be 7A! Everything was cleaned up to bright metal and new proper fuses installed. Everything works properly again.
But now it's midnight again and I still haven’t had a chance to ride the bike hard and see if the smoking clears up. If it doesn't, the top end will have to come off, and that's all there is to it. No need to wait for winter. And the job should be pretty easy now, since this arrived today…