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Electronic ignition

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p@ul:
I have a 750/4 sohc f2 that is a pig to start and warm up. Before i start taking it apart as a Cafe Racer project i want it running properly and i'm thinking seriously about replacing the the points with Electronic Ignition. Does any one here have any experience of fitting and tuning one of these and how much better the engine runs once fitted ?

Cheers Paul.

mick:
Hi Paul just my 2 penneth a well set up CB750 with points and condensers should start dead easily,

personally i prefer the points coz at least if something packs up you can usually rig something to get you home

were as electronic ignition can leave you stranded, just my opinion  ;) cheers Mick.

keithK2:
Hi Paul,
I agree with Mick, if the timing and carb balancing is done carfully it makes a massive amount of difference to cold starting, idling and pick-up at all throttle openings. Having run-in my 750 K2 i also rechecked valve clearances, adjusted cam chain and  reset points gap (dwell).
Hope this helps.

UK Pete:
F2,s have to be set up spot on and even then they dont like the initial warm up , reason is honda set them up really lean , and compensated with a fuel injector to overcome the flat spot from idle, there is a cure but it takes a bit of messing about, i have read somewhere ( i think on the honda chopper site) that you can drill out the idle jets ever so slightly to richen up the slow runing circuit, or you can buy the different jets from sirius,
Electronic ignition is definitely better than points, so i would recommend that, but wont give you many advantages to well maintained points, also i would consider rebuilding the carbs paying very close attention to getting the pump and injectors fully working as this has a huge influence on slow running and warm up, there are many posts if you search the forums or google
Pete

K2-K6:
I knew two owners of the F2 when it was new and can add to the good advice above in that the original setup of the choke was done to allow the tickover to be 3000rpm at full choke.

They always seemed to start fine but would be difficult to pull away on if you backed the choke in too early as you'd have to keep blipping the throttle to get the accelerator pump to richen the mixture (it only pumps as you rotate the throttle, not when the carbs are kept at a steady state).

One of the owners always fretted about the revs that Honda had set it to on a cold engine but they assured him it was absolutely correct, it never gave any problems.

I know full well the pros and cons of different igniton systems but my experience with these motors showed me that they just aren't that senstitive for starting if they are even close to being accurately setup.

This is the most consistently successful method I've seen for starting the 750F2;-
Before you do anything you need to open and close the throttles twice to pump some neat fuel into it, then open the choke fully and hit the starter. It should fire and settle at about 300rpm, then just leave it for about 1/2 mins and you normally will here it start to run a bit too rich, so at this point you can start pushing the choke in to get it running evenly.

When it's hotter, you can just pump the throttle once or twice to get it to fire straight away.

Don't blip the throttles when you shut it down a this leaves neat fuel in the motor which during extended period will dilute the engine oil.

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