Topic: CB750 Rebuild K0

[77379]

Thanks for the encouragement. Your bike turned out fantastic. Do you have any idea roughly what VIN that duck tail seat changed to the flat back seat? Also, any idea when the wrinkle tank was no longer being used?

[Stev-o]

Frame looks good, 77...

[Sgt.Pinback]

Ducktail seat for all K0, flat one came with K1.

Don’t know how long the wrinkle Tank came, but your early KO should have it.

Sorry to say but your bike misses some expensive K0 parts (double cut front fender, HM300 pipes, K0 seat , recessed ignition switch ...)

[BPellerine]

might still have the 2 hole rear fender though.

[77379]

It was wishful thinking on the rear fender. A previous owner had put extra holes in it anyway to mount the rear turn lights so he could fit larger side bags. The guy I bought it from kept those for some reason. I realize there are a lot of expensive hard to find parts missing but that is the way it came. In a package I got two other K0 bikes both of them are missing the tanks and they are both later VINs. That is why I was wondering when they stopped using the wrinkle tanks. The tank that came with this bike is a repairable wrinkle tank fortunately.

[BPellerine]

well you might have enough parts to build one nice one!

[Don R]

 Watch for the rolled rear rims. They are rounded on the bead area. No flat side at all really. Hard to find and expensive to buy. I rechromed the one on my sandcast. The Chrome guy said, you realize you can buy a rim for less. I said yes, but not this style rim. Good for him being up front about it. If you find two, call me lol. 
 
 You may find yourself looking at a lot of improperly listed parts on ebay. Knowledge is power in this case.

[HondaMan]

I finally finished with most of the black paint work. I first bead blasted everything, then primed with PPG primer surfaced. A little bit of sanding on the pitted areas and then shot with a PPG 9300 Concept acrylic single stage urethane. I used a flattener on the paint to bring the gloss down about ten percent because that seems to be the original gloss on these frames in the visible areas. The pure acrylic urethane looked a little too glossy. I’m happy with the way it turned out. It seems like every project becomes two projects. I go to bead blast and the blaster needs to be fixed first, I go to paint and the gun is missing in action. Two steps forward and one step back but I’m making slow but steady progress.

I'd like to raise a point here: in the 1970 frames Honda forgot for a while to include some drain holes in the lower frame. Since the K0-K2 frames (and even some K3) have an opening at the rear of the cradle where water can (and does) enter the lower frame, causing the frame to rot right at the back of the lower front engine bolsters, they were all supposed to get a 2.5mm (1/8" close enough) hole AFTER paint, just behind each bolster, on the bottom. We got a memo' from Honda about these in late 1971, asking the shops to check for, ostensibly, "painted shut holes in the lower frames". I have seen quite a few frames so adversely affected, and repaired a couple with new welding and new paint - all apart, of course..

[Terry in Australia]

It was wishful thinking on the rear fender. A previous owner had put extra holes in it anyway to mount the rear turn lights so he could fit larger side bags. The guy I bought it from kept those for some reason. I realize there are a lot of expensive hard to find parts missing but that is the way it came. In a package I got two other K0 bikes both of them are missing the tanks and they are both later VINs. That is why I was wondering when they stopped using the wrinkle tanks. The tank that came with this bike is a repairable wrinkle tank fortunately.

Ha ha, I've got a K0 fender with holes in the same spot, except mine is painted white because it was a cop bike fender. I'm glad I'm not trying to restore a K0 now, those "unobtainium" parts are stupid prices.

[77379]

Instead of making one bike out of the three, if I can finish this one and if I have any money left I may take a stab at finishing the others. They are all missing the same expensive parts.
I’m not real clear on the rolled rims. All six rims appear to be egg shaped if I was to look at a cross section of it. I don’t see any flat part on the outside or inside. Maybe a picture of the two different rims would help identify them.
I didn’t notice any rot or even excessive rust anywhere when I bead blasted the frame. I even tapped around on it quite a bit listening for anything odd but all seemed to be ok. I like the idea of drilling the drain holes. I don’t plan on riding in the rain but it happens.

[Stev-o]

I may have a front rolled rim that I dont plan to use.  Will have to check condition.