[Stanley]

Battery?
My CB750 was sensitive to battery condition. Otherwise, tiny jets are likely plugged.

[mattsz]

The bike seemed to run well at that time - the current owner claimed the starter switching was intermittent.  Anything goes, now, I guess, since it's been sitting...

[Arizoni]

My 4th motorcycle was a 1975 CB400F.
Fantastic motorcycle.  It's only shortcoming was the Yamaha RD 350 could clean its clock.

I rode my 400F well over 25000 miles and when I sold it, it was running just as good as it was when I first got it.

[Richard230]

My 4th motorcycle was a 1975 CB400F.
Fantastic motorcycle.  It's only shortcoming was the Yamaha RD 350 could clean its clock.

I rode my 400F well over 25000 miles and when I sold it, it was running just as good as it was when I first got it.

I traded-in my 1973 Yamaha RD350 to buy the 400F. My RD had constant problems with gorped up rings and fouling spark plugs. I thought the Honda was a better motorcycle than the Yamaha, although it wasn't quite as fast as it wouldn't rev over 8,500 rpm. 

[Bilgemaster]

I don't recall seeing hardly  any  RD350s in Britain in the '70s. However, the RD250s were simply everywhere in obnoxious wailing ring-diggydee swarms because of the then motorcycle license (or, rather, "licence") laws, whereby basically any pimply doofus or spotty wanker could get a so-called "Provisional Licence," like a kind of Learner's Permit, with no testing whatsoever, valid for any bike up to 250cc to "learn on" for a year before testing for the full licence. These laws may have made some kind of sense when a "hot" BSA or Triumph 250 could muster up maybe  20 hp or 70 mph flat out on a good day with a brisk tailwind. But the RD250, more than any other motorcycle, was probably responsible for all the subsequent changes to the law, to the point where one nowadays needs to create a spreadsheet to understand what bikes one may or may not now ride.

Capable of over 100 mph, glorious suspension-bashing wheelies down the High Street, and typically indifferently maintained by a succession of inexperienced owners who seldom held onto them for much longer than the year or so it took to take the driving test, get a full license, and then buy something bigger and frankly, nicer, the RD250 was the original "organ donor special" and probably killed or crippled more British kids than German Buzz Bombs did during the War. Usually falling apart and/or weirdly bent and/or brakeless by the third or so owner, poxy fucking death traps, they were...And just marvelous for some, I suppose.

[mattsz]

Oh, man... I want one of those for free instead!