assessing the condition of a motor

[superUPer]

I have the motor from my 84 700 parts bike up for sale. I am trying to learn more about it so I can pass that information on to potential buyers. Since a broken alternator chain is common, how can I tell (without taking it apart) since this motor is not in a frame and does not have a starter? So far I have taken the alternator cover and one of the side covers to access the crank shaft. It turns over smoothly with a wrench. When I turn the crank, the alternator also spins. Does that tell me anything? The gear that the starter would crank on turns over easily by hand. Should that one turn with the motor?

As for the transmission, when the motor was in the bike it would shift through the gears fine. Can you determine anything from that without having a load on the tranny?

[ariwhiteboy]

I would recommend removing the covers and doing a good visual inspection with pictures for your potential buyers. You could also rotate the engine manually and listen for any funny noises.  Most buyers know that buying a used motor is a crapshoot though and will be reaady for any potential problems that may be waiting. Good luck with your sale.

[Munkey]

If the alternator is turning when you turn the crank, then the chain has to be intact. That's the only link between the two.

The starter clutch will spin freely in one direction but not the other if it is good (or at least as good as you can check by hand). Spinning freely in both directions is bad.

[gammer]

So far I have taken the alternator cover and one of the side covers to access the crank shaft. It turns over smoothly with a wrench. When I turn the crank, the alternator also spins. Does that tell me anything? The gear that the starter would crank on turns over easily by hand. Should that one turn with the motor?

Very good testing!
Yes, if you turn the crank over, and you see the alternator turning at the same time...then this indicates that the alternator chain/starter chain is not broken and is functioning.

The gear that the starter would turn, should spin freely one way by hand. But should not spin at all the opposite way by hand.

As for the transmission, when the motor was in the bike it would shift through the gears fine. Can you determine anything from that without having a load on the tranny?

This would tell me that the transmission is functional and that it was put together (if ever apart) correctly. It would also indicate that the shift forks are functional too.
It does not indicate how much wear is on the shift forks or on the transmission.

Also note: Not being able to run the engine makes it hard to listen for noises and/or knocks. Something that some folks use to determine if there is a worn bearing or gearing.

[superUPer]

The starter clutch only turns in one direction as mentioned. I was able to make the pto (if that's what it is on a bike) turn by monkeying with the shifter. So who wants a motor?