Another 81 brought back to glory

[pgilliam1]

History:
I just bought this bike, 1981 CBX, from an estate sale. Has 18K miles and has new body panels and looks new.

I turn on the ignition switch and the correct lights come on. I hit the start button and can hear the starter switch click nice and strong and then nothing happens. I removed the starter motor and put 12V directly to the motor and it turns freely. I reinstalled the starter motor and put 12V directly to it's terminals and nothing happens.

Could it be a weak starter motor?

I tested and fully charged the battery and jumped the leads to another known good battery with the same results.

I changed the oil, took off the oil pan and cleaned the strainer and nothing looked unusual. I replaced the spark plugs and they were all loose and looked a little rusty on the outside, but were not in bad condition and the electrodes were not carboned up at all.

The previous owner has installed some kind of a kit to replace the original stator. It has an aluminum plate with what appears to be an alternator bolted to it that must have the regulator built into it because the original voltage regulator is disconnected (the 2 plugs coming from it are not connected to anything).

Any ideas at this point would be appreciated. TIA!

[NobleHops]

How did you put power to the starter on the bypass? Positive to the terminal and negative to a frame ground?

Do we know the motor is free? Put it in neutral and remove the right side crank cover, put a socket on the crank end and make sure it's free.

You said batt is fully charged, right?

[daves79x]

Nils made some good observations. Once you find the engine to be free, put everything back as it was and just jamb a screwdriver between the 2 posts on the solenoid - key doesn't have to be on. If the starter turns the engine over, simply replace the solenoid. If not, then you have a weak starter.

Dave

[pgilliam1]

How did you put power to the starter on the bypass? Positive to the terminal and negative to a frame ground?

Do we know the motor is free? Put it in neutral and remove the right side crank cover, put a socket on the crank end and make sure it's free.

You said batt is fully charged, right?

I took the starter off the bike and put 12v to the terminals and it spun freely.

Battery is fully charged and I even jumped a known good battery in parallel to the existing battery with no luck.

I don't know if the motor is free. If I take the crank cover off, will oil spill out? Does it matter which direction I turn the engine from the crank? How much force/torque should I have to put on the crank for it to turn? If it won't turn what should I expect and what should I do?

Thanks for your help!

[pgilliam1]

Nils made some good observations. Once you find the engine to be free, put everything back as it was and just jamb a screwdriver between the 2 posts on the solenoid - key doesn't have to be on. If the starter turns the engine over, simply replace the solenoid. If not, then you have a weak starter.

Dave

Shorting the solenoid posts is the first thing I did. Nothing happened. Even in neutral I do have to pull in the clutch lever to get the solenoid to click. I assume that means I have a bad neutral start switch as well?

[NobleHops]

How did you put power to the starter on the bypass? Positive to the terminal and negative to a frame ground?

Do we know the motor is free? Put it in neutral and remove the right side crank cover, put a socket on the crank end and make sure it's free.

You said batt is fully charged, right?

I took the starter off the bike and put 12v to the terminals and it spun freely.

Battery is fully charged and I even jumped a known good battery in parallel to the existing battery with no luck.

I don't know if the motor is free. If I take the crank cover off, will oil spill out? Does it matter which direction I turn the engine from the crank? How much force/torque should I have to put on the crank for it to turn? If it won't turn what should I expect and what should I do?

Thanks for your help!

Let's back up if we don't know the engine is free, pull the plugs, put an ounce of Marvel Mystery Oil down each spark plug hole with a turkey baster. Give that an hour to think about itself, then pull the right crank end cover (dry under there) put a wrench on it and see if it turns (clockwise) with the plugs out. You could have a stuck ring. It should not take a lot of force to turn it.

Let's let Dave opine further though before you bust the wrenches out.

N.

[pgilliam1]

How did you put power to the starter on the bypass? Positive to the terminal and negative to a frame ground?

Do we know the motor is free? Put it in neutral and remove the right side crank cover, put a socket on the crank end and make sure it's free.

You said batt is fully charged, right?

I took the starter off the bike and put 12v to the terminals and it spun freely.

Battery is fully charged and I even jumped a known good battery in parallel to the existing battery with no luck.

I don't know if the motor is free. If I take the crank cover off, will oil spill out? Does it matter which direction I turn the engine from the crank? How much force/torque should I have to put on the crank for it to turn? If it won't turn what should I expect and what should I do?

Thanks for your help!

Let's back up if we don't know the engine is free, pull the plugs, put an ounce of Marvel Mystery Oil down each spark plug hole with a turkey baster. Give that an hour to think about itself, then pull the right crank end cover (dry under there) put a wrench on it and see if it turns (clockwise) with the plugs out. You could have a stuck ring. It should not take a lot of force to turn it.

Let's let Dave opine further though before you bust the wrenches out.

N.

I will do this. I have been scouring the manual and found out to turn the engine clockwise reading the timing section. An ounce of oil in the cylinders seems like a lot to me but I've never had a seized engine before. Any idea on what an engine rebuild on this bike would cost?

The estate sale people told me they started this bike and it ran and idled well just 2 weeks before I bought it. I did check the oil before I bought it and it was dark but full. I know - "buyer beware". UHG! Thanks for sticking with me!

[NobleHops]

If that's the case, skip the mystery oil for the moment, just pop the cover and see if it turns 1/8, even with the plugs in. This is just a quick binary test, is the engine free or not.

[daves79x]

Shorting the solenoid post should have resulted in at least a lot of sparks. That makes a direct connection from the battery to the starter, key on or off. Testing the starter on the bench should result in the thing nearly jumping off the bench when 12v is applied.

But see if the engine is free first. Don't get too excited just yet about something major being wrong. One step at a time.

Dave

[pgilliam1]

Shorting the solenoid post should have resulted in at least a lot of sparks. That makes a direct connection from the battery to the starter, key on or off. Testing the starter on the bench should result in the thing nearly jumping off the bench when 12v is applied.

But see if the engine is free first. Don't get too excited just yet about something major being wrong. One step at a time.

Dave

There were sparks when shorting the solenoid.

I was holding the starter by the positive lead (it was dangling in the air) when it attached the battery. It didn't jump much but it spun freely.

Off comes the crank cover. All my fingers are crossed this engine spins freely. I'm still not sure how much pressure to apply to the crank bolt. I have spun car engines that way, but really fear breaking this. I'll go easy and will let you know. Thanks Again!

[pgilliam1]

The engine turns very smoothly from the crank bolt - HUGH SIGH OF RELIEF! I can feel the compression strokes as I turn the bolt and there are no rough spots.

Next check?

[NobleHops]

That it has good ground via that funny comma-shaped arm to the frame and engine hanger bolt.

[pgilliam1]

That it has good ground via that funny comma-shaped arm to the frame and engine hanger bolt.

I'll try to find that. To be sure, is it on the right or left side, in front of the engine or rear, top or bottom? Sorry if that's too many questions! But would that cause the starter not to work, even if I shorted the solenoid? I ask because the battery terminals are connected directly to the starter motor.

[NobleHops]

That it has good ground via that funny comma-shaped arm to the frame and engine hanger bolt.

I'll try to find that. To be sure, is it on the right or left side, in front of the engine or rear, top or bottom? Sorry if that's too many questions! But would that cause the starter not to work, even if I shorted the solenoid? I ask because the battery terminals are connected directly to the starter motor.

The negative should be running to one of the bolts, I think to the left of the starter motor, which you can kind of see how it would be in this photo of my engine getting tilted back-when:



The positive lead on the body of the starter should be running to one side of the solenoid, and the other side of the solenoid to the battery, right? And that sparked when you shorted it, so the current is getting there, and presumably past it when you short it. And you have checked and tested the positive lead as you described, and the starter worked, powered through that positive lead, then I am suggesting the next thing to check is that negative lead. Check it for continuity, cleanliness, tight connection on both ends.

[pgilliam1]

Yes, all that is correct. The positive lead from the solenoid to the starter looks new and was tight. The negative lead from the battery also looks new and was tight at the starter mounting bolt. Actually the starter looked fairly new as well. The previous owner (deceased) had done quite a bit to this bike, but with him being gone and no one else in the family having a clue, I'll never know what all he had done.

I guess I'll wait to hear from Dave before I rip the starter out again, but I'm leaning towards it being bad. The rebuilt ones on eBay are going for over $160, so I want to be reasonably sure that's my next step.

Thanks Again!