"Poor Kid" 1981 CB750K - first build

[canyoncarver]

There is some great news. I'm picking up another bike tomorrow for certain. A clean titled 1981 CX500C... and when I get it, I'll have two 81 Hondas in the garage. People are telling me not to buy another before the first is finished, but if you knew how cheap it was you'd get it too.

HA......wish I'd heard that one a few bikes ago....

[Maritime]

Good get, always good to have one waiting for when the first is finished   the CX's are easy to work on, valves are a breeze, carbs come out super fast etc.  You started with the harder bike having 4 of everything, the CX is half the work LOL.

[kraptastic k]

I've heard the CX will be ultra reliable and it will be a favorable commute bike, in comparison to the highway-sprint style of my CB. I sure wish I knew! Either way, I'm sitting in my living room, waiting to go get it. Two isn't too many.

[kraptastic k]

Uh oh... Look what I found.

1981 CB750K
And
1981 CX500C

[McBrenner]

Now that is a great starting point on a CX. I wish mine was half as clean as that at the get go. Good luck to you on it. Any directions you are going to go with it after the CB?

[kraptastic k]

Thanks! Everybody sees the crazy good deals on bikes... Thought my turn would never come, but now I have a solid platform for build #2.

Yes, I'm very excited to build another purpose driven bike. Since the CB is my highway sprint bike/tuner, I would like to make a reliable commuter bike that can hop curbs and dodge down shoulders. Probably some MX bars and very few other mods.

I'll post a link to the build thread and tell the story better.

1981 CB750K (getting there now)

[pr design]

I'm pretty sure I saw that one on my craigslist the other day
Are you in the Triad?

[McBrenner]

Heck yeah man, exactly what I'm building my cx for. A solid runner for around town, backroads, but still able to do a 300 mile trip to college without worry

[kraptastic k]

McBrenner, that's spot on. Something that I won't be frustrated on in traffic. Or something that gets me out of said traffic.

No, I don't think this bike was listed... Snagged it from a shop in Corinth, TX. Bitch of a drive

1981 CB750K (getting there now)

[kraptastic k]

I ordered two bunk ass petcocks and I'm thoroughly disappointed with both of them not fitting.

Some haphazard fabrication also ended up with the worst brake light I've ever seen. It will have to do for now.

Brass pipe fittings and a bit of improv have left me with a true rat setup. The new starter relay is also bunk I think- I had to jump it with a screwdriver.

The idle is extremely high now with consistent fuel flow. Backfiring occurring every 15 sec, but I won't let it run like that for intervals of more than 8 sec. Cyl #1 & 4 seem normal. 3 is cold and 2 is very very hot, assumed lean. Adjustment of the idle mixture screw did not appear to help.

Theories: vacuum leak at the boot. Can a bad seal at the exhaust header cause a lean or high idle condition?

Pilot fuel system could have clogged in carb 4, aka cyl 2?

No spark at cyl 3?

The issue with fuel spilling from the air filters is eliminated. No problems exist beside the faulty starter, the still-leaking case cover, and the above conditions.

Please advise.

1981 CB750K (headscratcher)
1981 CX500C (back burner)