Topic: 1978 CB750K Replacement Tank Options?

[Curt]

Hi.

I'm new to this forum and have a question, so maybe someone can advise.

I have a 1978 CB750K and the tank is getting a bit aged. I've cleaned it, soldered up some pin holes and coated it but am thinking it's time for a replacement.

Could someone please let me know which model years have interchangeable tanks for '78 K without modifications to the tank or frame?
Alternatively, if there's a fairly easy mod to adapt a tank with a cap on top instead of the trap door, I'd be interested in that too because I prefer the look.
Not looking for a $500+ aftermarket tank, but something functional that would look good on the CB.

Thanks.

[Stev-o]

The '77 CB750K tank will fit perfect. 

[Wobbly]

K7 and K8 use the same tank. K8 might have a blue or red stripe. K7 always has the red stripe. The F2 tank will fit as well. I have a complete  K7 tank and side covers (candy alpha red) for sale  in excellent condition, near mint. Just saying...

[Juan1]

A 77 and 78 k tank will direct swap.  Other years of CB tanks will require installing that year's seat, and modifications to the hinge as the earlier seats attach slightly forward of the 78.

[Wobbly]

modifications to the hinge as the earlier seats attach slightly forward of the 78.

Actually, the earlier models also have the hinges on the opposite side.

[martin99]

The F2 tank does fit, but it is longer. So you can use it, but then the seat won't fit.

I have this problem but the other way round. I want to fit a K7/8 tank to my F2, but doing so leaves a gap of about an inch in front of the seat.

[Curt]

Thanks everyone for the replies.

Looks like the best thing might be to look for a good '77 or '78 tank, and so no modifications to the tank or seat to get it to fit. I have enough bike modification projects as it is..... and it's time to ride.

Unless someone here has a nice tank they want to sell, I'll just keep an eye on ebay and wait patiently for the right one to pop up. There's a few on there now, and as ebay goes, there will be more on there later too. No rush.

In the meantime, some good riding weather is here. I haven't ridden the 750 much the last few years, but it's coming around again and I forgot how good it feels to ride this bike. If anyone has a tank they want to move, just drop me a message. Thanks.

[Curt]

Ok, that didn't take long....

Picked up a rust free original '78 tank on ebay for $30 + $40 shipping. 

Same tank which came on the bike originally, same color and no rust but a small dent which I think I can pop out. Anyway, it will be here next week. If it's not as nice as the one on the bike now, I'll strip it down and repaint it original black. 

Oddly, or maybe not, repro Honda gas tank decals are $140 from what I can see from looking so far  . I'll probably pass on the decals ... black with the gold Honda tank emblems would be good for me, and I think look great on the bike.