Hi everyone,
I picked up this bike in November of '14 and would like to document it. I did some cosmetic things over the winter when I wasn't working on my other bike, but I mainly bought it because it was something I had always wanted, and managed to scoop it up for 400 bucks with no title. I'm not super concerned about not having a title, however; I'll get that taken care of.
The CB750 is my second motorcycle. The other I bought from a friend for $200 barely running when I decided that I would like to work on/modify motorcycles as a hobby (in addition to riding them on the street as opposed to the dirt).
This was the day I brought home the 1982 Yamaha XJ750 Maxim:
And this is as it sits now. Pardon the Honda Emblems, I was feeling those out as I wait for some Yamaha ones to be delivered that will fit the CB400 tank's mounting points:
It's nowhere near done either, but I wanted to get it reliable and rideable for the summer before I began working on this. One bike not running is bad enough, let alone two. I have a build thread over at XJBikes.com if anyone's interested (Same username). They were a huge help, as I had never wrenched on a thing in my life before last September.
So, back to the CB. I picked it up from Craigslist after seeing the ad listing it for $550 when I called a guy who had posted it about four hours earlier. He said he already had a guy coming to look at it, and so I made him an offer for $400 and said I'd grab a truck and be there much earlier then him. I ran the VIN very quickly, and the deal was done. The guy I bought it from was a super nice young guy with a kid on the way and one too many projects. He knew what he was doing with his cars, so I was happy to buy it from him and take his word (he was very helpful with helping me start the title process months later). The story was that he bought it from a guy who wanted to cafe it, and chopped the wiring harness/threw some drag bars on it; that was it. Apparently it had been sitting for a while, but we weren't sure exactly how long. This was in November of '14 the day I brought it home.
Included in my $400 CB750 purchase was a CB400 Hawk Tank, Side Covers, Comstars, Engine, Front End, and some other odds and ends. It also came with a brand new Mac 4-1/Silencer and a set of new tires, so I'd say I made out (it was missing the stock mufflers and I would have changed them anyway).
For the bike, I plan on keeping the original paint/tank the same, and for this one I will not be doing an open frame concept; I'll be keeping the sidecovers in tact since they are not cracked and all mounting points are there.
That said, When I was cutting the frame on my XJ preparing to weld an upswept hoop in place, I cut the frame on the CB as well to begin to visualize how short I wanted it. Sorry to the purists, but that's the way I like it.
I took all of the surface rust off of the wheels/rear shocks over the winter, then painted them with Rustoleum Appliance epoxy, followed by Spraymax2k after a week of letting that Epoxy gas out. Other than that, the bike sat dormant until two weeks ago. Once my buddies and I (luckily they're big, because I'm not) pushed it up 12 steps out of my basement using a rudimentary but solid ramp, I began to do what I needed to do to get it running. I started by cleaning the carbs. That said, I did not break the rack, or even take the tops off. I simply took the bowls/jets off and cleaned the visible passages/jets.
Then I rewired using this diagram:
The PPO had done some messing around with the starter solenoid and starter key so everything I did was not exactly as shown above, but it did work once I got some things figured out. This winter I'll do a full on rewire with some more colors for clarity, but again, I'm just trying to get it running well first. Even so, I went ahead and used the crimp connectors/waterproof casings from Vintage Connections. Frankly, I don't know why anyone would rewire without these, They're truly excellent. The ratchet crimper does a hell of a job.
This picture shows the new wires mixed in with the old. I still need to wire in a horn, blinkers, taillight, speedo, starter button, etc, but that's no problem.
I threw some atf/acetone into the engine through the valve cover ports (bear with me while I learn the proper terminology, folks) for a couple of days, then drained the oil and filled it back up with some of this Valvoline and a new filter.
I actually picked up a couple of the FramCH6009 filters from Advanced Auto for around 5 dollars, and from what I've read, they work fine.
So at this point, I'm ready to start the bike. The plan was to have it kick only, because why the heck not. As I'm going through the wiring diagram I notice the starter motor is wired in there and I think to myself "why would that be in there if it's minimally wired? Could it be that the key switch in the diagram is actually an automotive style ignition? Oh well, lets hope it starts. (If anyone could answer that, I'd appreciate it, but it's something that's been bugging me).
So after putting the key in the ignition and turning it on, I have a headlight, which is a good sign. I kick a few times with nothing, and forget that I didn't use any choke. Three kicks later, and we have a runner!
Now, I had no filters on the bike so I didn't want to run it for more than about 30 seconds, but it Idled very well at first. 20 seconds in I noticed some smoke (was dark, didn't see exactly from where, could have been numerous things), but I thought that might be natural for an engine sitting, or from the coating of the exhaust.
About 25 seconds in the revs started picking up, so I shut it off. I'm sure I'll need a carb sync and it couldn't hurt to soak the intake rubbers in some wintergreen oil, either.
One thing I'd like to note is that there was a ticking noise, maybe up near the valves. I can only assume I'll need to adjust those as well, so hopefully that's the cause.
The next evening I put together a quick seatpan from fiberglass that I'll foam and upholster to use for the remainder of the season. It's not at all permanent or great looking (and actually needs a bit more trimming to sit right on the frame), but it took all of an hour of work time to make, and will be completely covered by vinyl so I'm not too concerned.
Anyway, here's where we're at as of 5 minutes ago:
The real fun starts now! While I will be going through the manual and using the search function before asking questions, I was wondering if anyone had a basic maintenance FAQ stickied somewhere; basically something that would explain how to get the bike tuned properly when purchased in less than ideal condition, and also things to look out for/check.
Appreciate it!
Time to read that manual.
