ford 8n starting probloms

[jwremodeling2006]

I have a 8n put new point condenser plugs wires cap, it has the original 6volt system still I crank it no start as soon as I hook the jumper cables to it fires right off runs perfect shut it off try to start with out cable no start if anyone could help me out please thank you.

 

[LD1]

When you say no start , is it cranking and not firing?? or is it not even cranking??

How are you jumping it?? Direct to the starter?? or battery??(I hope not)

Hows the spark? coil?? Unkook the coil wire out of the cap, hold close to ground, are you getting a consistent bright blue spark that will jump 1/4-1/2" every time??

Lastly, perhaps the engine is just getting tired and low on compression, and the 6v system just dont spin it over fast enough.

 

[Soundguy]

ditto.. answer those questions to help us help you.

many times if the battery is weak or bad cable connections, the starter spins slow.. and / or there is not sufficient power for the coil witht he starter laod.

jumps increase starter speed and provide extra power to t he coil.

post back

 

[jwremodeling2006]

it cranks but wont start there is fire but seems to be week but I throw some jumper cables on the battery and fires rite up I know you are not supposed to jump it like that but it starts right up I was told the ignition switch could be going bad . Now I jumped it today and ran it shut it off and it started up without jumping it but tried it again no start.

 

[Grahamguy]

Does your tractor have a ballast resitor in the ignition system?

 

[jwremodeling2006]

no its built in the coil.

 

[LD1]

DO NOT JUMP TO THE BATTERY,

THE BATTERY IS 6v. With jumpers you are giving it ~14-15V.

IF jumping with 12v is necessary, do it direct to the starter.

IF spark is weak at the coil output, replace the coil and go from there. Coils are cheap. Blown up batteries and a face full of acid is not

 

[LD1]

PS

IS this a front mount distributor, or side mount??

 

[Soundguy]

no its built in the coil.

i call BS! on that.

prove to me that you can buy a coil with a resistive element built in. you will be hard pressed to do so.

Coils for 12v are built with specific number of turns of wire in the primary, and the correct gauge, to produce the correct impeadance and or dc resistance.

if this is an early unit with a square coil.. it will either hav ethe oe style 6v coil, which requires the oem ballast resistor.. or it may have a newer style coil that is marked for use with 12v, however.. those coils rarely are anything but 2 - 2.5 ohm primary.. not the 3 - 3.25 they should be. thus using the oem ballast resistor or some other add on resistor is needed for the front mount coils.

if it is a round can side mount.. you have the 6v and 12v vaiety. you have to read the wording ont he coil carefully. some sa6 12v w/ external resistor. meaning they are a 6v coil and can be used in a 12v application if you add an external resistor.

if you don't run the correct serial resistance you will have problems. 12v coils on 6v yeild weak sparks. 6v coils on 12v reduce coil and breaker contact life, sometimes drastically.

give us exact info on what you have as your ignition setup and charge system.

have you done a voltage check onthe battery when cranking?

checked across the starter cable when cranking to see what the v-drop is?

have you cleaned all bat posts, wire terminal ends, ground connections, etc?

are you using good 1/0 cables ?

the wimpy 4ga universal replacement cables most auto places sell are insufficient for these applications.

 

[LD1]

if this is an early unit with a square coil.. it will either hav ethe oe style 6v coil, which requires the oem ballast resistor.. or it may have a newer style coil that is marked for use with 12v, however.. those coils rarely are anything but 2 - 2.5 ohm primary.. not the 3 - 3.25 they should be. thus using the oem ballast resistor or some other add on resistor is needed for the front mount coils.

if it is a round can side mount.. you have the 6v and 12v vaiety. you have to read the wording ont he coil carefully. some sa6 12v w/ external resistor. meaning they are a 6v coil and can be used in a 12v application if you add an external resistor.

Precisely why I was asking if it was a front mount or side mount. We really need to know what we are dealing with.

the wimpy 4ga universal replacement cables most auto places sell are insufficient for these applications.

Excellent point, ESPECIALLY on a 6v system. You need BIG cables...