Topic: CB750 Big Bore Kit

[jaytee-nz]

There's a CB750 big bore kit for sale here in NZ.
Just curious if anyone has ever heard of the manufacturer or knows much about it ?
There are no rings, missing valves and rusty piston pins so it's been for sale for quite a while now.

[cooldrum]

ForgeTrue was a company here in the States in the 1960's.  They made bore kits for Honda 305's , Superhawks and Scramblers.  Later on, offered kits for 750's.  I believe the company is no longer around.  I ride a '67 Scrambler in addition to a stock K4 so I'm familiar with that kit name.  That kit is worth to you how much you want to offer them. Good Luck!

[jaytee-nz]

Thanks for the info - was more curious than interested in buying it.
My CB750 is completely stock and I'd like to keep it that way.
I doubt that rings would be available so that makes it pretty much useless I think.

[754]

I found an old set of TRW pistons, stock rings fit, except the top was snug.  2nd and 3rd groove fine.
I think if I took 1bor 2 thou off the top ring it would be fine.

[jaytee-nz]

Frank - I'd be happy to bring it over to sunny Canada for you. Would only cost an airfare and maybe 3 weeks accommodation - what do ya think ?

[754]

Hey its 2 small for me.. get the piston size, some were 11 or 812.. I think 64 mm..
 Stock rings for 750 would not fit them ( mine were high comp stock bore.
 These use Cb350 over size  rings , in many cases.

[jaytee-nz]

Yeah, in the listing it states 64mm piston size.

[scottly]

Those look like my 836 TRW/Alcoa pistons; maybe Forged True re-packed them and sold them under their own name?

[PeWe]

There are lots of new pistons for CB750 for not that much so why bother buying old stuff in a bad shape.

[Jerry Rxman Griffin aka MuthaF'er]

Yeah, in the listing it states 64mm piston size.

64mm land sizes 1.5, 1.5, 2.5mm = CB350 twin rings