Starter Stays Engaged-on my second rebuild

Bought the bike...love the bike..haven't yet ridden the bike.
High-pitched squeel...starter trashed- yah, wouldn't turn
Rebuilt Starter
Started Three times...BEAUTIFUL 750 sound (new plugs, clean carb.)
Starter stayed engaged third time...high pitched squeel,turned off bike FAST
Starter fried again.
what next?
thanks

 

Checked your solenoid they have a tendency to stick on.

 

ditto...check for power at the starter if the starter still screams after the engine fires.

 

thanks all
Bike ready...so far changed to diff. starter (not the same rebuilt) so far so good...one cell trashed on battery. Buddy is convinced that'll solve it...solenoid and stator ok. Still a bit concerned about trashing another starter, but will double check solenoid like you both said
thanks !

 

Interesting post...

Lately, after I have started the bike up on SOME occasions I start hearing some sort of continuous whining noise coming from the crankcase area - haven't pinpointed it yet because as with most intermittent problems it only happens when you're on the road and can't do anything about it. If I turn the bike off and back on again the noise disappears. Recently I had the starter of and when I put it back the wiring into the starter must have moved causing some sort of short. When I pressed the start button I just heard the solenoid sounding off continuously, and the tach needle jumping...but no power to the starter. A little realignment of the power wire into the starters side and she starts up fine. But still occasionally I hear that whining sound. Solenoid or not to solenoid...that is the question. Will have to take a closer look soon but bike runs fine and normally except that when I hear the whining noise I start to worry - and it's not really a loud or grinding sound, just a subtle metalic wheezing sound. Will report back when I have resolved teh issue.

 

From my experience with the Starters; they start acting-up after they've been half way through the Brushes.

Intermittent starting begins when the carbon dust from the Starter Brushes fouls the armature, and shorts-out the Motor or makes it act "Sluggishly"

Dried-up grease in the Mechanical end also slows-down the Starter and makes it tough to start the Bike.

Beyond 20-years on the same Starter and you can have BOTH symptoms acting in unison to prevent the Starter from engaging the Starter with sufficient power to get the Bike to go.

The best course of action is to Overhaul the Starter.
Clean it.
Both ends.
Get some New Brushes in there.
Clean the Planetary Drive and grease it up good with a synthetic waterproof grease.

Be sure to clean and grease bushings and bearings.
Make sure the Power Lead from the Brush to the 12 Volt Power Post isn't shorting itself out against the case of the Brush Holder.

 

Might be worth adding to this...

Ihave seen on eBay starter repair kits for around US$30. If you've got the starter out might be worth swapping the old parts for the new - I think it contains some basics like brushes, brush holder etc. Also, when I took my starter apart about a year ago the commutator was starting to appear slightly concave where the brushes have connected. This can be shaved slightly to clean up and flatten out the commutator by someone in the trade.

When I took the starter out the first time you would not believe how much built up grunge and grime was INSIDE, around and on the magnets and on the armature. Get in there, clean away, WD40 is a good cleaning agent, and make it sparka larka larkling clean. At least this will minimise any problems that may be associated with the starter itself.

 

When I clean-out a Starter Motor I use Isopropal Alcohol in a Trigger Spray Bottle.

Load the Sprayer with the Alcohol and keep spraying until the fluid that is dripping-off is as clean as the fluid you are spraying-on!

Cuts the Carbon Dust and flushes it away without doing any harm to the internals.

After you get it cleaned-up nice ... then, coat the parts with a little WD-40.
You don't have to waste a Can of WD-40 doing the heavy cleaning.
Let the alcohol do the hard part.

 

Is it possible for the starter button on the handlebar is sticking?

 

Very Possible.
Get a can of Electrical Contact Cleaner from Radio Shack.
Shoot some in around the Switch.

Also:
Start the Bike without using the Push Button Switch.
Turn ON the Ignition.
Use a Jumper and connect the two High Power Posts on the Solenoid to engage the Starter and start the Bike.

Once the Bike has Started; remove the Jumper Wire (or whatever you use to short across the two terminals).
If the problem goes away; the Push Button Switch is suspected.

If the Starter Motor dies not disengage; "Smack" the Solenoid with the handle of a big screwdriver of handle of a small hammer to determine if the Solenoid is sticking.

Don't hit it hard enough to fracture it.
But, do give it a firm whack if the Contacts are sticking together and still supplying current to the Starter.

 

Thanks for all the great stuff, everybody!
So far....trashed the brushes completely on that last stick open, so I picked up a different reconditioned starter for less than the parts to rebuild it, and so far so good. Another issue turned out to be the voltage regulator and a dry cell on the battery that damaged it. So far, solenoid ok, starter clutch working allright (tho I think I still need to get in there and clean it out and put new grease in). So HOPEFULLY with a cleaned up carb, it won't stick at high revs and freak me out at a stop either! whew...almost there!
thanks again, all.

 

You don't need to grease the Starter Clutch. It gets splashed with engine oil as the Bike is running.

You DO need to be sure that the Grease in the Mechanical end of the Starter Motor is not all dried-up and causing the Starter to labor.

The Mechanical end has a shaft, twin planet gears and a planet gear ring that should be nice and clean and greased-up with fresh waterproof grease.

 

Rick what is the best way to clean the old grease out? What works best is probably a better way to put it?

 

Brake cleaner and compressed air! An old toothbrush helps get the chunks out.

 

Cool thanks Robert!