1978 CB750F2 - Poor Starting

[blackeagles]

Have you set the "fast idle" adjusting screw?  As there is a routine for that which should hold the revs for you without having to play with the throttle.

The absolute peak rpm when on full choke is 3,500 rpm too,  which with UK temperature is probably needed, not necessarily to run all the time at that,  but more to set the relationship of ambient temp/ mixture/ engine warmth so that it works correctly.

I think so (something of a fiddle when its on the bike) i.e. pull the choke all the way out and back the grub screw off until it just touches the cam then push the choke home and turn the screw back in 1 1/2 to 2 turns.  I did notice that the cam was well worn to the point that the screw falls out just as it touches the cam so I had to drill a very small hole in the screw end and fit an even smaller screw into it so it would reach the cam.  something of a bodge but it works.

[blackeagles]

well, so much for being smug.  since its a bit better weather and given that what I think is poor starting is fairly normal I thought I would give it a last adjustment of the pilots and fast idle screw while its cold and start it...…..no such luck!!

with petrol pouring out no 1 overflow 

cant get it to work so will have to take the bowl off - without taking the carbs off yet again oh

[kthree]

You can fit K series carbs quite easily. You'll need new throttle cables (slightly shorter), and set of K series carb boots. Plus you'll throw away your current choke set up
Not sure about the airbox setup - it might still line up, but if not, you might have to go with pod filters.
Hope this helps.