Starter Issue Maybe

[BlackCloudSalvage]

Picked up a 1989 XL1200 Sportster recently.
As far as I know there is no motor upgrades.

When I bought it, it fired up easy, but then went to fire it up the other day for only about the 3rd or 4th time and got a whirring sound and motor wouldn't spin.

A buddy suggested it was the starter clutch. I'm not super in the know on the inner workings of starters. So we pulled the starter and swapped it for another USED starter.
With the primary, clutch basket, etc off we hit the start button and verified the gear would come out and spin. Then we reassembled the primary drive but left the cover off and hit the button, starter motor gear comes out, engages into starter ring on clutch basket, puts tension on it and trys to spin it but cannot and makes the same sound we heard initially with the first starter that came on the bike.

Next, we pull the plugs so there's no compression.
Hit the button and starter works good and turns the motor.
We put plugs back in.
We check the voltage drop on the battery while we hit the button. Drops to 8V or lower. Won't spin the motor.

We pull my buddy's truck up, remove battery from the motorcycle and put jumper cables direct to appropriate wires that go to the battery terminals.
Hit the button and motor spins.

We figure we've got a bad cell in the battery.
Go get a brand new battery. Hook it up, hit the button, motor turns over. Figured we had it. Put the seat on, and get ready to give it a test rip, hit the button......

Same old familiar sound. No go.

Thoughts?

2 bad starters?
Starter clutch?
Bad wiring somewhere?
Weak batteries?

[JBinNC]

Battery and cables first. Do some checking with your voltmeter and you should be able to narrow it down.

Jim

[BlackCloudSalvage]

Well today I put the initial starter back in. Cleaned all of the connections and tested the cables by a method I read. Meter lead on negative terminal and ground, hit starter, should be minimal voltage less than 0.3V . Same on positive terminal at battery and starter motor. Checked out good.

Same situation. Will spin with no plugs in it, but put plugs in and it can't turn just engages and trys but slips I guess.

With plugs in I measured voltage drop on battery while trying to start it. Dropped down to like 9.5, but then like 2 trys later it dropped to 6. This is a brand new battery reading 12.5 volts.

Oddly enough, it did spin it once with the plugs in for just a sec then started slipping again. That's when I noticed it was dropping voltage again.

I'm stumped.

[JBinNC]

A fully charged, new AGM battery should read 12.8V. That figure will drop as the battery ages. If your new battery only readv12 5V, it was not fully charged.

You say the starter is "slipping." If so, the voltage at the battery should read higher when the slipping starts, because the load on the starter decreases. If the starter is instead dragging, and the battery voltage is dropping, then the battery is bad (new or not) or the starter motor is drawing extra amps.

Jim

[farmall]

Inspect the contacts inside the solenoid as those are the main wear parts on Denso OSGR starters. The later Sporty OSGRs fit and replace the early Densos which are no longer supported (but contact kits fit).

Your local auto electrical place can load test those starters (many autos use Densos). That eliminates the starter as a cause. They probably stock contact kits.

[Guest]

sounds like the common problem of the starter clutch breaking down under load,
the prequil to going completly,
ALL BALLS do good replacements,
to test i mount in a vice & use a strap wrench to apply a load to it in both free spin & drive directions,
& just when you think its good, it gives & spins.
this is why when in, it spins it with the plugs out, but the extra loading given by the plugs being in, adding compression to the forces involved,
& the starter clutch starts to break down.
this has been a Harley problem point for years.

[BlackCloudSalvage]

Thanks yall. I'll do some more testing soon and will continue to update the thread. Hopefully with the resolution!

[BlackCloudSalvage]

sounds like the common problem of the starter clutch breaking down under load,
the prequil to going completly,
ALL BALLS do good replacements,
to test i mount in a vice & use a strap wrench to apply a load to it in both free spin & drive directions,
& just when you think its good, it gives & spins.
this is why when in, it spins it with the plugs out, but the extra loading given by the plugs being in, adding compression to the forces involved,
& the starter clutch starts to break down.
this has been a Harley problem point for years.

So I tested one of the starter like this. Didn't even need a vice. Used my hand to hold starter and used my hand to spin the gear. Looking at it aside it was on the bike looking into the primary I can easily free spin it clockwise which would turn the motor and then with some force like opening a pickle jar I can rotate it anti clockwise.

Is this truly a good test of the starter clutch? Or does it need to be activated to test it?

JB has me thinking because like he said, the voltage should go back up if slipping?

[Guest]

it is a one way clutch,
if it can turn either way freely or when under load it is fucked,
if it locks in one direction only & spinning freely in the other direction it is doing its job,
you say you can turn it both ways.... therefore towit & not withstanding, its fucked..............
it is a mechanical unit, not effected by electricity.

[Revelator]

swap in a different battery. "New" batteries can go bad anytime.
And as farmall suggested, check those solenoid/starter contacts, they take
a beating & will get pitted & dirty during their life.

[farmall]

You can replace the starter clutch while you're at it. Densos are easy to work on which is why they're on millions of vehicles. HDs are rather tough on starters compared to multi-cylinder engines. Pics show the innards:

http://www.chopcult.com/forum/showthread.php?t=52178

I'd inspect brushes and commutator (easy to clean) but those tend to last a long time.

However if the starter turns the engine with high amps applied than the clutch is not the problem!

[BlackCloudSalvage]

Thank you all. More to follow. Will open it up in the next few days and report back. I have a 2 year old daughter so I get stuff done little by little 20 minutes at a time these days.

[farmall]

Any kit with these parts (I've used several of the linked example) will do. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Agree on the All Balls starter clutches (there are many sources of Denso clutches, the AB parts use metal roller cages instead of plastic). Any local rebuilder could likely get a heavy duty clutch dirt cheap as they rebuilt heaps of Densos for Japanese cars etc. Everything I've bought from AB worked well. (I fucking LOVE their one-piece starter jack shafts not least since they don't use the silly intermediate bushing so they can be used to run (for example) later FXR outer primary covers on earlier Denso style inner primary covers like when I modded an early Delkron inner primary to work with the 1994-up outer. The seal remains of course. )

[BlackCloudSalvage]

Starter issue Update

Well.... I'm still stumped. It's frustrating because I'm usually not a parts swapped but this one has me stumped.
Replaced the starter clutch with new ALL BALLS unit.
Replaced the 2 main contacts, studs and plunger with new parts as the old ones were grooved and dirty. Charged the battery.
First hit the button and I could hear plunger pull in and push out the gear but no starter turning. Seems it wasn't making contact, maybe needed to adjust the plates. Pulled off the solenoid cover and just used a mallet handle to push in the plunger and its up to its old ways. Will not turn the motor, although it keeps trying. Pull the plugs and it turns over fine.
I did notice with the cover off that when pushing the plunger onto the contacts I would see spark/arching.

I'm embarrassed to say this, but I did realize that although I have tried 2 different starters, each with its own positive cable. I still have not pulled and cleaned the ground cable. But, I thought my method for testing it was fine. I ohm checked it and checked the voltage spike on it when cranking. Earlier on I also took another separate new ground cable and bolted it to the motor mount and negative terminal by passing the other cable.

I don't know what else to do. Tried 2 different starters, same issue. Rebuilt one with new contacts and clutch. Haven't messed with either motor yet but seems unlikely that'd be it.

Maybe it's time I look at the emgine? Seized valve or bad lifter causing a compression lock?
Bike ran fine. Didn't seize while riding.
I'm just lost hahaaa!



Also I may have been wrong about the clutch slipping. When I tested it by turning by hand with starter out I still had the clutch in the housing so it let me free spin in one direction but was able to spin with force applied in the other direction. That would just be spinning the entire unit in the bearings. When I had the clutch out, held by the large gear, I could not spin the starter gear in reverse. Well Anyhow I guess it doesn't hurt to have the new AB unit.

[Revelator]

Do a load test on the Battery
check for worn brushes on the motor and make sure the armature is clean where
the brushes ride.
Check all connections positive & ground.