Re: My first CB750!! Maybe.

Posted by rich on
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/My-first-CB750-Maybe-tp3630351p3630924.html

The charging problem is, as you mentioned, most likely the rotor. Rewound units can be had for about $135 (plus a $60 refundable core charge). The link to the site that's selling them for that price has escaped from my bookmarks but I can find it again. I think it was "Rick's" something or other.

There's an outfit on ebay selling the rotors for about $100 but I've heard nothing but bad about their warranty exchanges.

The charging rotors are known to fail on the 79-82s.  High RPMs combined with heat and age can cause them to short. It's not a big deal, after all the original did last 30 years!

I got my bike for $500 because it needed a rotor and a new gas tank.

Unlike the 69 to 78 CB-750s, there's not a lot of after market restoration or customization parts for the later models. Most engine components can still be obtained from Honda and a quick ebay search will reveal there are dozens of them being parted out at any one time, so you'll be able to find parts relatively easy (for a 30 year old bike).

Any used bike is going to have its problems and likely need maintenance items (chain, sprockets, tires, air filter, and so on) so leave some money in the budget for that stuff along with the charging issue and maybe a battery too.

Having a mechanic look at it is a great idea. Listen for unusual noise from the cam chains, they can be adjusted but if they've been ignored for a prolonged time, damage may have occurred. Also, a lot of people take off the stock air box and use "pod" type individual air filters. These can be really, really, tough to get working right with constant velocity carburetors used on these bikes.