Topic: Yet another CB750 starter question

[CBR954RRacer]

I purchased a 72' CB750 last month that I have not been able to get started using the electric starter.  The previous owner said that he replaced the starter motor already but that it did not fix the problem.  I did the "pliers" trick with the solenoid(shorted the two large post) and nothing happed(except seeing some sparks).  You can hear the solenoid clicking when you hit the starter too.  I then took the starter out and hooked it up direct to the battery, and it spun up pretty quick.  So in my mind the starter gear is locked up...right?  I just wanted to get a second opinion before I go tearing into the engine case.  Thanks.





Bike in transition from stock to cafe --->

[HondaMan]

Umm...does the engine turn over OK?
The starter engages the crankshaft thru a roller clutch. The starter shaft engages the center of a double gear , which is the reducer, which in turn drives this roller clutch. The reducer gear can hardly be locked, as far as I can tell, and if the roller clutch were locked...well, there might be some racket when the engine is running.
 

You may have to take off the alternator cover to see what's going on in there.

[CBR954RRacer]

Yeah the engine turns over just fine when I kick start it.  I just wanted to see if I was headed in the right direction before I open up the engine. 

[mystic_1]

With the starter already out, you could maybe stick your finger in the hole where the starter shaft goes, you should be able to feel the intermediate gear with your finger.  It should be free to turn in one direction but not the other, due to the operation of the starter clutch.

Like HM says, there's not a lot to go wrong with the starter gears short of catastrophic damage.  Pulling off the alternator cover only takes a little while and would probably answer any questions about the states of the gears.

Since you have the starter out, hook it back up to the starter cable, ground the starter to the frame, hold it firmly and hit the start button.  Does the starter spin?

mystic_1

[chrislib]

The contacts in the solenoid might be pitted, just because you hear it click does`nt mean it`s conducting electricity. These solenoids can be taken apart and inspected/cleaned but it`s a pretty delicate job (bakelite is VERY unforgiving). I had to do this on my bike as the contact plunger was sticky but I was too cheeep to spend the $$$ on a new solenoid.