12 volt conversion

[wickerham]

I recently converted my 8n to 12 volt (side mount distributer) It ran fine when i first did it then we didnt start it up for two weeks now it won"t start. It turns over fine but it seems by looking to have a week spark at the plugs I did replace the coil as well and put on a resistor. Any suggestions please

 

[Bruce (VA)]

Most sidemount coils don't need a resistor. Why did you add one? What was the value of the resistor you added?
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[souNdguy]

Hmm.. you replaced the coil and added a resistor.

Why did you replac ethe old? 6v coil? was it bad?

what resistor did you use?

you didn't perchance put on a 12v coil like a napa IC14SB did you? if so.. the ressitor is limiting your spark by cutting primary current needlessly.

Also.. recheck the pointsgap and the contacts themselves.. might have slipped or coroded after all that tinkering.

soundguy

 

[wickerham]

no i ordered it from yesterday. I replaced the 6 volt coil after it wouldnt't start because I thought the resistor was bad and they sent a resistor with the 12 volt coil

 

[wickerham]

they sent it with the 12 volt coil with limited instructions but most points are 8 volts aren't they dont i want to reduce it down from 12?

 

[souNdguy]

Hmm.. more details... siad you repalced a resistor with one they sent.. what was this other resistor?

the more complete details you post.. the better answers you get.

In the future.. do more diagnostics and less parts repalcing.. it's way easier on the wallet, and is fun to learn about your machine in the process.

soundguy

 

[Bruce (VA)]

Lets think about this for a minute.

Did you have to change the points when you converted it to 12v? If the points were "8v", how did they operate when it was 6v?

Get out your multi-meter. Measure the value of the new resistor and the new coil. Then, look & see if there are any other resistors still in the circuit. If so, measure them.

Sounds like to much resistance in the circuit, but do not take my word for it; that's what they make meters for!
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[wickerham]

it was the same resistor they sent the first time when i got the conversion kit. I am not very good in diagnosting I can change parts or figure things out but i a m not familiar with this conversion. i reead the diretions and did it so when they sent the 12 coil and a new resistor i figured it went on with it

 

[wickerham]

I dont know I am asking because i am not familiar wiht this i read instructions and do it I hoped i could get some help and insight i will get the multimeter and try it

 

[Bruce (VA)]

You have just discovered the #1 problem w/ many 12v conversion kits. The instructions leave a lot to be desired. Unless you have a better than average knowledge of how these tractors work, you will quickly find yourself w/ a non-running tractor by assuming that the instructions are correct.

First off, get the meter. If you own a 60 year old tractor, you need one.

Next, while you're out, go by NAPA & get a IC14SB 12 coil. (tip # 30 at the link below) Install it w/ no resistor, period. Make sure there are no other resistors anywhere in the circuit.

This will probably get the tractor running. If not, then you have a meter to keep checking things & a coil that you know is good w/o any resistors.
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[old]

Did not start it for a couple weeks could be as simple as needing to clean or replace the points. Point do not like to sit for long with out being used and if they are closed corrode and then do not work

 

[wickerham]

thank you I will get the meter and by pass the resistor i appreciate it i will try it tomorrow and get back to you all

 

[D Lewis]

Bruce, Is that coil for a front or side mount? I have a front mount distributor and was going to get a new coil and would love to not have to worry about a resistor.

 

[Bruce (VA)]

The NAPA IC14SB is a round 12v coil & does not need any resistor. I'm sure other 12v round coils are made that do not need resistors either. But, all front coils need at least the OEM resistor, even if it is an alleged "12v" coil. If it's a 6v coil & a 6v system, the OEM ballast resistor is all that's needed. If you have a 12v conversion & keep the 6v coil, you need more resistors & you might need more even w/ the "12v" coil. You will not know for sure until you determine coil resistance w/ a meter.

The pic shows 1.5 ohms on a 6v front coil.

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[D Lewis]

Thanks,

I am ordering a 12v coil off this site, will measure when I get it. I am rewiring per the schematic I got from Sean, and some other things like diodes (not a single wire alternator), and I could not find a resistor in the system like the one shown as standard.

On 12v systems does a gauge reading volts make more sense?

Dave

 

[souNdguy]

Yikes!

There are no '8v' points.. points are a switch.. they don't care.. 6v, 8v, 12v.. etc.

Coil cares about current which is determined by primary resistance of the coil, and any ressitors inline.

True 12v coils DO NOT USE A RESISTOR on 12v.

We will need to know what kind of coil you have.

Ideally you should check the primary current thru the coil with points closed with and without your magic resistor.

Not sure why they sent a resistor AND a 12v coil.. both are not needed.

When I said learn some better diagnostic techniques.. I was not refering specifically to the 12v conversion... besides.. same diagnostic techniques needed to troubleshoot the oem 6v genny will help you troubleshooting a 12v alternator system.. electrons are electrons...



soundguy