# IH 454 No spark and weird wires



## scarnucci (Nov 16, 2010)

I have a IH 454 4 cyl gas that I was having to use ether to get to start for me towards the end of last year. I ran a can of sea foam through it on the last day I used it, and first thing I did this spring was change the plugs and wires. Now I cant get any spark. Ignition coil is less than a year old, probably 20 hours run time on it. Ive reset gap on points, rotor button and cap are newish and good. 

Biggest puzzle is this. I ordered the wires from my local IH dealer. He looked up part number and told me what I needed. I put my resistance meter on the wires when troubleshooting my lack of spark. New wires read infinite ohms. I had the old wires laying around, measure 0 resistance (ie short, or "Good") I did this for all five of the new wires, they all read infinite ohms. I went back to the dealer to see if he could explain it, and he pulled new wires off the shelf that all read infinite ohms (at 200 ohm range) It just doesnt compute to me, why the wire that is moving that little spark has that kind of resistance. Their only explaination is that the new wires are "different" than the old ones, but cant offer me how or why they are different. Can I get some old style wires that measure like a wire should and see if they work? 

I finally bit the bullet and had them pick it up and take it to the dealership to get it running. When I went to check on it a week ago they said only one old timer in the shop can work on the old tractors, and they were swamped with mowers at the moment...sigh.

Any advice would be appreciated.


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## Country Boy (Mar 18, 2010)

Have you checked to be sure the points were clean? They can corrode and not make contact any more. You can clean them with a points file or some emery cloth, and they need to be shiny for best results. Also, are you getting good voltage to the ignition coil when cranking? You should have at least 9-10v there to get a decent spark when the engine is cranking. Voltage drops in the system when you crank the engine over, so reading the voltage when the tractor isn't cranking won't tell you much.


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## scarnucci (Nov 16, 2010)

Points were new when cap and coil put on last summer/fall.

Got it back. They put a new cap and ignition coil on it. Said previous cap was melted inside, and mechanic didnt like the feel of the old coil.

Coil was less than a year old, as was the cap. I'm happy to get it back and running for around $200, but like I said, parts were fairly new to begin with. Also, I still dont understand why the new wires were measuring infinite ohms.

Ran it more or less all day today, little to no issues. Towards the end of the day I was having a helluva time putting it into 1st gear from 2nd. Trying to plow in 2nd was a pain.


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## hackware (Sep 14, 2011)

scarnucci said:


> Points were new when cap and coil put on last summer/fall.
> 
> Got it back. They put a new cap and ignition coil on it. Said previous cap was melted inside, and mechanic didnt like the feel of the old coil.
> 
> ...


multimeters measure resistance using DC current (batteries)...

ignition circuits deal in KV in the 100's to 1000's pulses per second (Mhz bandwidth), where a DC "open" is actually a Hi-Freq "short"...

Hi-Z (impedance) leads are used to reduce EMI (electromagnetic interference) to radios/TV/cellular/etc. services...

using ether/acetone/other highly volatile "spirits" to start motors can change the "spark gap" circuit drastically, and cause "burn troughs" to coils/rotors/points/distributor-caps as seen by your mechanic...

william...


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