MTS1100 starter

[koko64]

June 2009 model Multi 1100. It appears to have the hot starter motor issues and my testing and a search here seems to point that way.

The starter label is worn and I can't tell if it has the non Denso starter. If so will the long running Denso version fit if I swap the gear? Bolt hole pattern change? Otherwise my sparky can rebuild it and beef it up if possible. Was there an upgraded retrofit or the same crap on the dealer shelves?

[ducpainter]

I don't believe that Ducati would make 2 different cases to use a different starter.

Parts list should tell which gears are different. I suspect just the gear on the starter, which is supplied by the starter manu. Again...I don't think that Ducati would tool up for different gears simply to use a different starter.

[Speeddog]

The only starter differences I've seen:

Transverse bolt through the grommet/support on the right hand end.
AFAIK, came around ~DS1k motor.

Different gear reduction parts:
At least two different sprag gears, can't tell them apart without counting teeth.
Intermediate gears to match the sprag gears.

IIRC, there's 3 different gear tooth setups on the starter itself.
Interchangeability, dunno.

[ducpainter]

Shows you what I know.

[koko64]

So I'm guessin' the parts number differences are mainly the gears on the end of the starter.

[ducpainter]

I guess the question is why are there different sprag, and intermediate gears. Is it to give one of the starters enough reduction to do the job?

[koko64]

Yep. Geared down for the hi comp litre plus bikes. I was worried about a change in bolt patterns. Not sure exactly when it changed maybe introduced with the change in primary gear ratios around 900ie?

[Speeddog]

Yes, different ratio geartrains to give the starters more advantage.

Pic info:

1098 starter on the top
9t integral pinion
27040101A
428000-5020

DS1000 starter on the bottom
13T removable pinion
27040051A
428000-1070

Both have the same mounting faces.

[koko64]

Thanks heaps

[koko64]

Update.

I have this bike to live with for awhile as the owner is O/S. Its good to live with a bike and fix those little things you notice while riding.

Testing of the starter with direct voltage under the hot, no start conditions finds it cranks fine while the normal starting procedure fails.

I will test the other components in the chain to see what fails when the bike is hot. The way the starter only cranks a slow half turn has me looking for an upstream cause of the resistance/voltage drop. The results are consistent and I hope its not an ECU issue, but some minor component. It really presented like the classic buggered starter, but it will crank hot with a direct voltage, but not through the starter button.

The wiring looks solid/upgraded, there appears to be no corrosion, it has a Shorai LFX18 and I am swapping batteries as a precaution. The solenoid runs right next to the oil cooler line. I will check the ECU earth wire for cracks that could expand and any relays, etc. I will double check the power cable to the starter motor, who knows, nd upgrade cable could be crimped bad and severed under the sheath.

I also note that the bike has aftermarket Oxford heated grips which will starve a LifePo4 battery a whole Volt and run the system under 13V at lower revs.

Cheers

[Speeddog]

I'd swap in a known good solenoid.

I suspect it's got a heat-linked high resistance or open condition in the existing solenoid, internal or external.

Is it cranking hot when you jump the solenoid, so it uses the onboard battery?
I'm not sure location is favorable to jumping...

[koko64]

Thanks for confirming that its a possible cause with these symptoms , as that test is on my list. Its in a good position as the protective cover can be clipped off and the terminals bridged. Its great to get confirmation of a possible cause as I've not seen solenoids do this with heat, but rather due to corrosion or a straight out failure.
The solenoid will be an easy option.

[Howie]

Or you could check the solenoid for voltage drop.  Check at the starter connection and ground too.  And yes, yuk can change resistance with heat. 

[koko64]

Thanks fellas.
Between the solenoid, a corroded main cable running to it, and power hungry grip heaters robbing the Lithium battery, the matter is sorted. The corroded power cable which had hidden crud feeds the solenoid and connects back to the (crank timer/meter relay?) and ECU which I believe can confuse Mr Marelli. It really smacked of that bad batch of starters, but glad it aint.
Concurrent issues always muddy the waters.
Thanks again.

[Howie]

If voltage drops below 9 volts during cranking the ECU drops out, no start where a carbed bike might crank slow, but start.