Topic: Cb400f engine swap just to get FI?

[Manitou]

I've read some about attempted fuel injection retro fits.  Seems the charging system of our bikes isn't up to par and little can be dine for that part(?).  This led me to the thought of a complete engine swap to a more modern engine.  I like the old school look of my 77, but my life has dramatic altitude and temperature changes (live in Tahoe, play in Sacramento or reno.. 6500' feet to about 0' altitude).
I'm starting to get the feeling I may regret picking up this particular bike.  I got it with the intent of a winter project, so I dint mind the wrenching.. But need a plan.

[Bodi]

The 400F has very limited electrical output as you noted. Getting an EFI system with its fuel pump powered will be a major issue. You could increase the alternator output by making your own but I haven't seen any drop-in conversions. There's always the hillbilly approach: I have a picture somewhere of a 70's Triumph 750 that had a car alternator running via belt from the crank end... maybe justified since it came with Lucas electricals.
What engine are you considering? There's not that much room - and a serious power increase would strain the chassis - but it sounds like a fun job.

[evanphi]

I agree it sounds more of an experiment/proof-of-concept project than anything... Totally fun sounding!

[Garage_guy_chris]

Take a look through the anders 32amp upgrade thread. Upgrades have been done and are possible. Im not sure if your bike shares a charging system with anything else like the 350 or 500/550?

http://forums.sohc4.net/index.php?topic=117735.0

[Manitou]

I haven't sized up engines.  Honestly, I thought someone would have already done it and wrote something about how they did it.  I read about someone using cbr600 throttle bodies, but was an unfinished project. Can the whole 600 engine not fit?  Surely there's some comparable modern engine out there?  Hell, I'm half tempted to even look at (dare I say) smaller engines like the ninja250.

[Bodi]

A CBR600 engine in a 400F frame would be suicidal. 85-100BHP is entirely insane in a 70's cradle frame originally made for a 37BHP engine - not to mention the tiny tires that will fit in it. Sounds like fun though!