f60 starter problem-update

[kellaig]

Hi there,

Well an auto electrician can't fault the electrics or the bbattery of the starting system.

He indicated that as it is an inertia drive starter motor the pinion gear spring may be too tight or tense alowing the ppinion gear to drop down as the motor begins to crank and takes the load of the spring. If it is too quick in releasing sometimes it may not start.

Sounds feasible?

How do you adjust the spring???

Regards'

Craig

[boats.net]

You can't really adjust the spring but you can replace it.

[kellaig]

Hi there

The outboard goes back tomorrow but they are at loss to explain why the load is coming off the starter motor whilst cranking. As mentioned earlier all the electrics have been tested and no fault found.

If this motor doesn't start quick enough the load comes off the bendix drive and it disengages failing to continue to crank the motor.

With the emergency kill switch removed the starter motor will only continue to crank the motor on less than 50 percent of the time. The rest of the time it diesngages

What causes the load to come off during the cranking process- is it compression or the flywheel which is new.

does the CDI have a part to play or could timing be off. All along i have had the impression that the motor has thought it has started but it hasn't quite got there and the bendix drive has disengaed prematurely.

I am losing patience??


Regards

Kellaig

[Ken]

Kellaig,
During normal cranking, the starter is trying to go faster than the flywheel and thus the flywheel acts as a drag (load) on the starter pinion and this is what keeps the pinion at the top of it's travel.
Once the motor fires and the flywheel spins faster than the pinion, then it pushes the pinion and spins it faster than the starter shaft and the pinion travels back down the shaft due to the spiral cut on the shaft - this travel back down is also aided by the spring of the pinion.
Since your starter pinion is failing to stay engaged, then I would suspect the following:
(1)The starter motor is not spinning fast enough - should have a minimun of 9.5 volts at the starter lug connector during cranking. This assumes a no load voltage on the battery of approx 12.5 volts. Monitor voltage during cranking.
(2)Could be a bad starter motor that starts out spinning fast enoough, but as soon as the windings heat up, then some short and the motor slows down.
(3)Could be bad starter relay - contacts of relay making poor electrical connection during starting and thus dropping too much voltage. Try connecting battery directly to starter with heavy duty jumper cables and crank motor to see if that makes any difference.
(4)The pinion gear may be hanging up on the starter shaft and not traveling all the way up to the pinion stop - you can observe it's travel during cranking - pull the ignition kill switch and crank the motor - if not traveling al the way up to the pinion stop, then remove starter and disassemble pinion stop, spring and pinion.
(5)If the starter had this symptom since new, then I might suspect maybe the wrong pinion spring. But if this is something that has just recently developed, then I don't think the pinion spring would suddenly get stiffer - break maybe, but not stiffer.

Hope this helps - as simple as the "Bendix" action of the starter appears, it's really pretty complicated as far as the spinning of the starter, pinion, spring, inertia, spiral cut of the shaft, and the engaging and dis-engaging of the flywheel.
Good luck [img]smile.gif[/img] ,
Ken K

[kellaig]

Thanks Ken,
the update is that after voltage drop testing- no fault found, replaced flywheel and starter, jumper leaded straight from new battery to starter the starter still disengages about 50 percent of the time whilst ignition kill switch is out.

The dealer thinks that this is a characteristic of the model and there is nothing more he can do and thinks it happens because of compression taking the load of the starter flywheel during cranking even with no start.
My conern is that this is varialble and should it either crank all the time or diengage all the time
'
Regards

Craig