noname
Well-Known Member
Anyone know if a pre engaged type starter will fit in place of the inertia type,or would it entail replacing the mounting plate too ? thanks
PERKINS 4108 STARTER
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Billjratt
Well-Known Member
The starter on my 4108 is ISOLATED, possibly more important than bendix/pre-engage. If you're about to change, check all the angles to avoid electrolysis problems in future.
essexboy
Well-Known Member
Both 3 bolt fixing and same ring gear according to my parts list, we used to fit a pre engaged to overcome a worn ring gear as it enters from the opposite side (Front ILO rear)
Pete735
Well-Known Member
Not sure what you mean by the mounting plate, but from memory it mounts onto part of the block casting, so not changeable I would have thought.
Having said that, one of the classic car companies advertised last year replacement pre-engaged starters for inertia types - I bet they are expensive though.
On the "isolated" starter motor, certainly they do not earth through the body - at least mine does not, but I've always assumed that this was to reduce electrical power loss in the system - it's a big lump to turnover so probably requires considerable cranking current. Anyone know what this current is by the way, I've always been curious about this?
Having said that, one of the classic car companies advertised last year replacement pre-engaged starters for inertia types - I bet they are expensive though.
On the "isolated" starter motor, certainly they do not earth through the body - at least mine does not, but I've always assumed that this was to reduce electrical power loss in the system - it's a big lump to turnover so probably requires considerable cranking current. Anyone know what this current is by the way, I've always been curious about this?
Billjratt
Well-Known Member
Current depends on stiffness of engine, health of compression,thickness of oil, denseness of air (theoretically!) etc. just accept it for what it is.
As for isolation, both the starter and alternator are isolated, and the negative is connected via a fusebox under the alt. It means the whole engine is away from the circuit, and thus will live longer due to avoiding stray electrical currents. Looking for electrical problems like you would in a car,(by probing from the chassis) will give misleading results, but it does mean you don't get a shower of sparks when you accidently touch the side with a spanner!
As for isolation, both the starter and alternator are isolated, and the negative is connected via a fusebox under the alt. It means the whole engine is away from the circuit, and thus will live longer due to avoiding stray electrical currents. Looking for electrical problems like you would in a car,(by probing from the chassis) will give misleading results, but it does mean you don't get a shower of sparks when you accidently touch the side with a spanner!
noname
Well-Known Member
Thanks for all your help,i will check out all the raised points and see if i have more luck!
Meantime if anyone has more input or a starter motor at a realistic price be good to hear from you!
many thanks all regards dave
Meantime if anyone has more input or a starter motor at a realistic price be good to hear from you!
many thanks all regards dave
VicS
Well-Known Member
[ QUOTE ]
Anyone know what this current is by the way
[/ QUOTE ] The manual gives a Max figure of 900amps but that will be stalled not the CCA figure normally referred to.
Anyone know what this current is by the way
[/ QUOTE ] The manual gives a Max figure of 900amps but that will be stalled not the CCA figure normally referred to.
Pete735
Well-Known Member
Sounds like you are looking for a secondhand unit - as indeed I would - but if new then try somewhere that sells tractors, preferably with a more "mature" person on the other side of the counter, these engines were used on a lot of agricultural plant at one time and if anyone makes kit last it's farmers and prices can be more reasonable.
