Topic: 750k Engines...

[jneuf]

So I have my cheap-o $110 CB750 overbore kit that I ordered off ebay that I'm wanting to install into one of my engines this winter...so here is the question I'm asking of all of you SOHC4 members out there...

The bike in question is my '74 cb750....I have two engines, the one out of my '74 that needs some welding done on the bottom case, and a '78 cb750K engine. Neither one is seized, but that's about all I know of both of them...is there any sort of advantage to starting with the '74 engine, or the '78? I know I'll need an offset sprocket for the '78 engine...

Appreciate the input 

[lucky]

The 78 engine is a much, much better engine.
At least 15 improvements.

[BeSeeingYou]

I believe the 77/8 K engine is the same engine used in the 75/6 F so yeah it's a bit better engine.  I would check to see if the overbore kit will work with that engine.  There are some internal differences (pistons and cam) so would an overbore kit for an earlier engine work with the later ones?  I don't know.

[Terry in Australia]

That 836cc kit will work with any of the K and early F engines, but not the F2/3. Cheers, Terry,

[754]

The  78 motor has different pistond than you 74....and LONGER sprocket shaft, than the early one (able to run wider tire than early ones, with standard sprockets)
 the late motor will work in earlier frame if you space rear sprocket or use correct carrier..