Topic: starter spins but nothing 72 CB500/4

[BlindSight]

Finally got my replacement button and spring and threw in a new battery and the starter sounds like its spinning but it seems to be spinning pretty fast so im wondering whats my next step to try and get this thing running. the bike has 14k miles but was sitting for about 20 years so im in the process of pulling the head to clean and check the pistons and see if they are frozen. pulled the carbs out and they weren't too bad off, the tank was rusted through though so worried about the transmission and motor being locked up and in need of a complete rebuild or replacement.

[nancy]

What happens with the kick start?

[Duke McDukiedook]

Battery could be shot, try to see if the motor will move rolling the bike in fifth gear.

Or see it you can crank the big timing nut clockwise on the ignition.

[BlindSight]

kick start moves pretty easily, doesn't feel like a whole lot of resistance. battery is brand new...will try and put the bike into gear and roll it tomorrow.

[BobbyR]

Finally got my replacement button and spring and threw in a new battery and the starter sounds like its spinning but it seems to be spinning pretty fast so im wondering whats my next step to try and get this thing running. the bike has 14k miles but was sitting for about 20 years so im in the process of pulling the head to clean and check the pistons and see if they are frozen. pulled the carbs out and they weren't too bad off, the tank was rusted through though so worried about the transmission and motor being locked up and in need of a complete rebuild or replacement.

Can you be more specific. Is the starter turning the motor fast, or is it spinning freely?

[333]

A quick pull of the points cover would answer these questions.

[BlindSight]

seems like the starter is just spinning freely...never heard one of these crank over normally but from my experience with scooters and cars im thinking it should be turning over more lowly and there should be more resistance in the kick starter.

[TwoTired]

First, you have to verify the crank is not spinning when the starter does.

The starter engages via a roller clutch inside the engine case.  Old, hard grease can capture the 3 rollers and prevent the springs from pushing them in place.  They are held out of contact by centrifugal force.
In some instances, simply getting the whole lower case assembly hot via a long summer run, and revving the engine will allow the heated grease to release their grip and allow the rollers to get pushed out for proper contact.

If you are not patient enough to wait for this to occur, then splitting the lower cases to get at the roller clutch mechanism is a more direct fix.

Cheers,

[Scott S]

 Take off the points cover and a tappet cover or two. See if the engine is actually turning over.
 If it is, then it's down to the old trifecta: fuel, air and spark. Do you have all three?

[hasko]

If in any gear and rear wheel pulled backwards, the starter will follow with its revolutions.This because oneway clutch is engaged. If those three screws inside oneway-clutch are broken (most likely) or rollers malfunction, the starter will NOT follow. Also sump and starter can be taken off, this makes you able to use finger to spin intermediate wheel one way only, if correct. Broken oneway clutch necessitates crankcase separation.

[wrenchmuch]

+1 on what TT posted .I would resist the temptation to mess with the starter clutch until after you get it running . I know it will be harder to start with just the kick but in my experience the clutch will come back to life once the bike has been run for a while unless it is damaged (unlikely ).

[BlindSight]

been raining cats and dogs and had to help the new roommate move in and the old one move out but not in that order...thanks for all the advice, hopefully will get to mess with this thing tomorrow.

[JBMorse]

I would like to add that when I bought my CB500/4 the starter was shot so I fixed it by always kick starting.  When I finally did get a replacement starter in there I was very surprised with how fast it spun with a good battery.  Just saying the engine could very well be turning and you just don't realize it. 
As mentioned above, pull a couple of valve inspection caps and the points cover and observe.  If the engine is turning, then you need to check for spark, fuel and air. 
Good luck!