Possible fix for slow starter motor speed with hot engine
Posted: Fri Jul 18, 2014 11:08 pm
I've bought an 8-tonne hydraulic crimper so I've made myself some new cables from the battery to the starter relay and from the relay to the starter motor...now the starter motor spins as fast when the bike is warm as it did when it's cold.
The wire im using should be a lot better than standard, the original wire is 50-strand 0.45mm diameter copper, im using 126-strand 0.4mm diameter copper, so thats an increase in cross-sectional area (used to measure the resistivity of the wire) from 7.95mm2 to 15.83mm2...should reduce the wire resistance by half, also my cables are a few cm shorter than standard so thats another gain as the voltage loss across the length of wire should be less. All this means that the wire should be able to deliver a stronger current, with a greater amount of voltage actually going to the starter motor, and should stand up to repeated starting and engine heating cycles.
If you are suffering from the same problem I'm offering the two +ve cables at a cost price of £11 +p&p. If you want the negative return only it will cost you £7 +p&p. And the full set of 3 cables is £16 +p&p. Postage rates are currently £3.50 for first class postage...so call it £20 for a full set.
The two +ve leads from Cradleys will cost you £60 (though one is now NLA) and the negative return would be £14...I can't find anywhere else to buy them?
All the wires will be fitted with 6mm ring terminals, except for the connection to the starter motor which is 5mm, and all the +ve cables will come with water/dirt covers.
Here are the ones im doing for Leey - now all complete, this is what you would get:
The wire im using should be a lot better than standard, the original wire is 50-strand 0.45mm diameter copper, im using 126-strand 0.4mm diameter copper, so thats an increase in cross-sectional area (used to measure the resistivity of the wire) from 7.95mm2 to 15.83mm2...should reduce the wire resistance by half, also my cables are a few cm shorter than standard so thats another gain as the voltage loss across the length of wire should be less. All this means that the wire should be able to deliver a stronger current, with a greater amount of voltage actually going to the starter motor, and should stand up to repeated starting and engine heating cycles.
If you are suffering from the same problem I'm offering the two +ve cables at a cost price of £11 +p&p. If you want the negative return only it will cost you £7 +p&p. And the full set of 3 cables is £16 +p&p. Postage rates are currently £3.50 for first class postage...so call it £20 for a full set.
The two +ve leads from Cradleys will cost you £60 (though one is now NLA) and the negative return would be £14...I can't find anywhere else to buy them?
All the wires will be fitted with 6mm ring terminals, except for the connection to the starter motor which is 5mm, and all the +ve cables will come with water/dirt covers.
Here are the ones im doing for Leey - now all complete, this is what you would get: