Restoring 78 CB750K8

[Restoration Fan]

My 17 year old son is a senior in HS and wanted to restore an old motorcycle for his senior project.  Since I've always been a fan of the CB Hondas (well, because they're awesome) and because there seemed to be a lot of parts and forums just like this one, we decided to scour Craigslist and see if we could find a target bike.  We picked up the bike in the photos for $500.  The fuel petcock was broken/missing so the tank was sitting to the side of the bike already when we got there but the bike does turn over on kick start with the little bit of gas that was in it.

As a rule the bike is mostly complete, but it was missing side panels, the previously noted petcock, and the air cleaner housing (top & bottom).  Also missing from the bike were the turn signals front & rear but the front ones were in a box with extra parts (new point and condensor for cylinder 2/3, couple of pieces of rubber tubing that looks like fuel line, and the boxes with old spark plugs which he had just been recently replaced).

I found and purchased the upper portion of the air cleaner housing on eBay that was correct for the 1978K model.  At this point, there's a lower portion listed on there that says it's for a 75 but the lister says that the bottom portion will fit any of the 71-78 models.  Can anyone confirm that the lower portion of the air cleaner housing is the same for these year models?  

By the way, the goal is to have him do a frame off restoration but avoid having to rebuild the engine unless we find that it's absolutely necessary.  I will have him rebuild the carbs, change both sets of points and condensors, paint the pieces that need to be repainted and have all the chrome re-chromed.  The front brake rotor looks like it needs to be resurfaced and it needs new pads there.  I'll have him check the shocks and see if they need to be replaced and he will have to dig into the wiring a bit as well since the electronic start isn't working.

In the end, I want him to get the bike to be a very nice daily rider and enjoy riding it for a short time before I have him sell it.  (I'd love for him to keep the bike but if he really thinks he might want to do this as a business, I want him to see how much of a realistic profit...if any...he can make out of the bike.  Once he repays my investment for the bike and parts, I'll let him have any profit he makes to buy another bike to restore & keep.)

Thanks in advance for any advice you guys have and allow me to say that I only found this forum 2 days ago and I'm already hooked.  You guys are awesome!

[TOOLS1]

This should be fun project for him. There are several parts suppliers for these bikes, and Honda still has a lot of parts available. The first place I go for most parts is vintagecb750.com or cycle-X. I doubt the engine will need rebuilt, about the only thing that kills these engines is moisture getting into them, and making them stick. However since you are removing the engine, I would recommend replacing the seals (we refer to them as nickles) under the cam towers that seal the holes for the headbolts. Not a complicated job, but you need to remove the engine.
I would also recommend doing a search for a writeup I did on removing the pressed in pilot jets in the keyhole carbs. It is almost impossible to clean them without removing them.
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[Restoration Fan]

Thanks for the response.  Usually when I have rebuilt carbs, I just go ahead and purchase the kit which usually has replacement jets.  Has it been your experience that the jets are usually just able to be cleaned with carb cleaner or do you usually recommend replacing them?

Also, do you have any idea if the lower half of the air filter/cleaner boxes was the same for all years on these bikes?

[TOOLS1]

I never replace the jets unless the bike needs to be re-jetted to run correctly. Also the pilot jets do not come in the kits. When I rebuild the keyhole carbs, I just order a packing set. It should come with the molded float bowel gasket (you do not want the one that just looks like a big O-ring), the tiny O-ring for the fuel screw, and 10mm X 6mm X 2mm O-rings for the fuel tubes. Then I will replace the accelerator pump since it is usually hard after forty years.
As for the breather box bottom, I do know they changed the way they attached to the top section at some point, but I am not sure when that was. You could go to Western hills Honda's web site and look through their parts fiches, and compare part numbers through the years to find out which ones will work.
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[Restoration Fan]

Thank you so much for your input.  Especially about the sites for obtaining parts.

I've had pretty good success so far obtaining parts, but there's one thing I'm having trouble finding and I'm hoping one of you guys has an idea.

The K model in 1978 has the tank with the hinge and the locking mechanism.  The tank on this bike is missing the lock, so I need to get a replacement.

Also, I'd like for the same key that already works with the ignition and seat lock/unlock to also work with the gas tank.  Do I just take it to a locksmith to have it keyed accordingly if/when I'm able to find a lock for it?

[TOOLS1]

Any Honda key will fit the gas tank lock, so no reason to have one re-keyed.
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[Re-run]

Don't you mean any flat head screwdriver will fit?

[TOOLS1]

Well that to.
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[Restoration Fan]

Several questions:
1.  Does anyone have experience with the Vintage Restorations paint?  Specifically, the Candy Alpha Red that was the 78 red color for the 750K.
http://www.ct70paint.com/alpha-red.html
If so, what was the experience...good/bad?  Specifically, I'm looking at the rattle cans at the bottom and wondering which package I should expect for painting the tank and the side panels?

2.  The tank on this bike has had some bondo work done on it and one of the things they did was to fill in and cover the holes at the front of the tank on each side where the Honda emblem is mounted.  How hard is it to tap for a new screw hole?  Is it easier to just try & find a replacement tank?

3.  Is there a measure with the drive chain for how much is acceptable slack in the chain?  This one seems to be a good bit looser than I would think is healthy.

4.  Anyone got a recommendation for a good set of tires for the 78 that has raised white letter tires?  I saw some on a bike the other day that looked really good on a bike of this time period.


As always, thanks in advance for any help.

[TOOLS1]

I have no idea about that paint company. I source all my paint locally. I have a company near by (KC Auto Panel) that will match, and mix any color I want. And they will put it into a spray can. You can contact them, and they will ship to you. http://www.kcautopanel.com/ However if if you are painting a tank, I would suggest using a spray gun. By using a spray gun, you have the ability to add hardener to the paint. This will make the paint more resistant to things like gas, and sunlight. As for the Bondo on the tank, just dig it out. You can use a sharp pick to clean it out of the holes. You can also heat it with a heat gun, or torch to burn it off.
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[Restoration Fan]

That's great advice on the bondo.  I wasn't aware you could do that.  As always, you're a great source of knowledge and many thanks to you for sharing that knowledge!

[Re-run]

Careful with flame though, it IS a gas tank. Shops that work on tanks will steam clean the tank before working on it.

[TOOLS1]

I just wash them out with soap and water. Never had a problem, but I always stand back, and put the flame to the filler hole before starting to work on the tank. If there is any gas fumes left, the flame will ignite them, and make a "buff" sound, and then you are good to go. However you should not be getting the tank that hot, and you can even leave it filled with water while burning off the Bondo.
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