Topic: Bugabeetle's Budget Build (1970 CB750)

[newday777]

How to punch the pin out(rivet)

[Bugabeetle]

Hello guys.

The carburetor arrived, along with the rebuild kit. Time to clean it up.

I also need to heat-shrink the starter motor wire. There’s some exposed copper.

The oil filter came in too.

Just waiting on the gaskets.

After that, I’ll clean up and fix the wiring.

More updates below:

I’ve basically stripped the bike. Removed everything broken or unnecessary.

I’m aiming for a true cafe racer feel, not just a “cool-looking custom bike” aesthetic.

Also, what is this? (picture).

[scottly]

That part goes in the starter motor, on the brush end of the armature. The flat tabs face the end housing, and are used to hold the brushes open during assembly. When the armature is installed, it pushes the washer out from the brushes and against the inside of the housing, where it acts as a thrust washer.
What carb rebuild kit did you get?

[Bugabeetle]

I just got the $25 eBay one. LOL. Same with the gaskets.

So in the end, I don't need that right? Just for assembly to hold the brushes (the metal blocks) open? Because it's not really shaking in there without it. I'm so lost. Maybe a picture or video or drawing. I've looked everywhere for a reference. Even the parts diagram don't have that anywhere.

Is there an @ option here? LOL.

[PeWe]

No that won't work that way. That odd carb is off a 1969/1970 K0. There will be carb body numbers on each that you need to see to tell if the hack that did that changed the whole carb body or just the slide.
There's a flat surface on the rack side to find the numbers.

One model more
064A
Original on 750 F0-1975
Needles 271307 clip at 3.

[Shtonecb500]

builders in NYC always amaze me, carrying out full builds on the sidewalks and #$%*. My bike started out as three different bikes, you have an early model year which is nice. What style of customs do you like?

[Bugabeetle]

My heart says "cafe racer". My mind says "street fighter". I'll just a mix of whatever for this.

[Bugabeetle]

So I worked on this for about 2 days. LOL. I just want a confirmation before i start crimping stuff.

So my logic is that the Ignition switch controls the +12v going into the starter motor. If it's off, it won't complete the circuit that starts the starter motor.

With it on, the Starter Switch can now be used. The ignition coils will now also receive +12v.

The rectifier is before the Ignition Switch. That means that it's always one. Matter of fact, since it will always be on, I will connect it straight to the battery positive.

That being said, am I good with this wiring diagram or is there problems with it?

[Bugabeetle]

That previous picture is fake. IDK who did that.

Take a look at this one. LOL.

[MauiK3]

If you don't have one, get Hondaman's manual, saves lots of time and heartache.

[Gurp]

Google JIS screw drivers. If your budget is tight get a set of Hozan brand ones. If you can spend some more get some Vessels. They will save you a lot of headache of the screws on that bike.

[Bugabeetle]

Got the pin out the gas tank. Time for some muriatic acid.

Finally finished rebuilding the carburetor: ultrasonic cleaned, new gaskets, new lines, and new float bowls. The only thing I didn’t replace was the O-rings on the main fuel connectors, but I read somewhere here that they’ll expand with fuel, so it should be fine.

The float bowl pins were stuck and when I tried removing them, I ended up breaking the holders. LOL. Pulled some “if it’s stupid but it works, it’s not stupid” shenanigan solution. Hopefully it works.

[newday777]

Replace those orings on the fuel tees. They will leak on your motor( and if have painted the motor, the fuel will eat off the fresh paint). It is far better to replace those orings than to think you don't have to relying on that ill advise given that they will swell back up. They might not swell enough to seal, then you will be pulling the carbs back apart again to replace them.

That's too bad you broke the pin holders. How many? What is it you are trying to hold them together with?
There is a member who micro solders the pins back together, which is the best fix.
I've seen a mention that empty .22 cal shell casings are the right size to slip over the busted posts but I can't confirm that.

[newday777]

This is Jim who repairs busted carb posts, micro tig welding them back together.

https://www.jmfmicroweld.com/

[Bugabeetle]

Thanks guys. I'll take a look at those but I'm on a budget so it might not be on the table right now.

As for the o-rings, you're right. I'll get on it. Also, secret. JK. I'll post it if it works. LOL. If I post it now and it doesn't then that's just embarrassing. Hahahaha.

I just finished a 20 minute full concentration muriatic acid. There's still rust on the bottom.

I got a gallon of evaporust. I'll do that for 2 days or something.. It really is only at the bottom. Hopefully, that gets it out.

LOL. I don't get how people can only do 1 gallon of evaporust for their whole tank. This thing holds 5 gallons. LOL. I'm not rich so I'll just roll with it.

I just put it in. Set timer for 4 days.

Also, wouldn't it be cool if we had a group chat or something? Like WhatsApp? LOL.

[newday777]

You do need 5 gallons of Evaporust,  not just 1......

[Bugabeetle]

I did muriatic acid. The weak small rust on the top, sides, and stuff is gone. The only thing remaining is on the bottom. That's where all the liquid ended up staying and forming heavy rust. That 1 gallon Evaporust covers the whole heavy rust on the bottom and then some, so I think I'll be fine with this gallon.

[BenelliSEI]

If the bottom is coated with the “varnish” old gas leaves behind, put a quart of MEK in first. It resolves it with in minutes. Read the instructions and handle with care….