Topic: '76 CB550 Elect. start

[stingray]

What can anybody tell me about the electric start in my 550 project?
Are they usually sound? Or unusable.  I put a battery in just to check out the electrics, which all worked by the way.  When I pressed the electric start button, the light dimmed and nothing turned.  The motor turns freely though with the start lever.
Thanks

[TwoTired]

 Since you didn't say, I'll have to assume the bike is stock in every way.
This can be a number of things.  But, let's begin with the start button itself.  There is a plastic assembly inside the bar control housing.  When the Master cylinder leaks fluid onto this switch, it disintegrates.  The switch ordinarily does two things when pressed.  Not only does it activate the starter solenoid (under the left side cover) it disconnects the headlight to reduce the drain on the battery. 
 Are you aware that you must have the bike in nuetral or the clutch pulled in before the starter will engage?

Next it could be a wiring and/or connector failure between the controls and the starter solenoid.
 There are two large and two small electrical connection posts on the starter solenoid.  The large posts are battery power and the starter motor.  The small posts will cause the two large posts to connect when 12v is applied across them.  Use some jumper wire to directly connect plus 12V and 12V return to those smaller terminals.  Be careful that if the motor does spin the bike is in neutral, as this bypasses the safeties.  Were it me, I'd try this first.

If the solenoid is bad, bridging the big terminals with a large chunk of metal (like plier handles) will put battery power to the starter motor.  If it doesn't spin now, you have to take out the starter motor to find out why.

[oldbiker]

As two tired says, if jumping the starter solenoid does not cause the starter to run then you must look at the starter itself. Remember that the starter is just an electric motor and has carbon brushes to carry the current to the armature. In a thirty year old bike these could be worn down to almost nothing. Thay are not expensive and an easy fix although you might find it a bit fiddly.