Jammed starter

[KREW2]

Hope someone can help.
I have a VP 2002, it has a 575cc amp starting battery, it has always sounded as if it is labouring to turn the engine over, but it always fires up after 4 to 6 seconds. Yesterday the starter motor jammed, it was easily freed with the starting handle, The second attempt I used the 2 leisure batteries and it fired up no problem. My question is, can I do anything to check incase there is a problem with the starter motor?

 

[VicS]

[ QUOTE ]
My question is, can I do anything to check incase there is a problem with the starter motor?

[/ QUOTE ] Well you could check all the engagement mechanism. start with the core in the solenoid, making sure there is nothing (rust) preventing its free movement then check that the lever moves freely on its pivot and that the pinion assembly moves freely. Also check the pinion teeth and the ring gear for damage.
Pre engage starters are not so prone to jamming as the old inertia types.

If it has always seemed to labour perhaps you should also be looking at all the electrical connections from battery right through to solenoid. negative connections as well. Always be suspicious of isolating switches especially the 1,2, both, off type.

 

[KREW2]

Vic
Thanks very much for your advice. I do have a 1/2 both switch which I have not checked it out, but today there was 12.74 volts at the terminals on the starter motor, or should I say at the lump on the starter motor which I think is a capacitor thingy? I don't really know. To check out everything else will necessitate the removal of the starter motor, possibly the engine. Should it happen again this is what I will have to do, Oh well!
I have to add today it started fine. As regards to it labouring do marine diesels tend to turn over more slowly than car engines

 

[VicS]

The lump on the side of the starter motor is the solenoid. The electrical contacts are at one end but at the other end is the mechanical gubbins that moves the pinion into engagement with the ring gear on the engine flywheel.


The 12.74 you observe merely tells us that your battery is well charged. It would be more informative to monitor the volts there while cranking the engine and even more informative to measure the volts dropped between there and the battery.

You might find some of the basic notes on Tony Brooks' website on boat electrics interesting.

 

[KREW2]

Thanks again, that web site is very informative.