This is a stumper on my friends Farmall A

B

brianJ

501 Club
My buddy Dave has been working on his A the last couple of days and has found a strange problem. He told me that the engine is not running right, kind of labouring to idle and wants to die off when he tries to move the tractor. So he starts messing around with spark plug wires. He pulls off the #4 wire with the boot just resting on the spark plug and the engine perks right up. Strange. So he tries the same thing with the #1 with the same results. He then has all plug wires off and rests the boots on the plugs and he said it never ran so well. What is causing this? The wires are new from the TSC. Plugs only have a couple of hours on them.
Ever hear of or see such a thing?
Brian
 
Brian,

maybe there is "foreign material" in the wire-boot? dust, grease, or paint could inhibit the spark; pulling it off might be making it arc, and connect more efficiently to the clean wire just inside the boot? i know that seems silly, to have an arc be more powerful than a close connection, but as i say maybe something's inhibiting the spark when it's connected. maybe something in the boot is grounding it out? remove the boots completely, and see what's in there - and maybe attach'em without the boots.

also, don't the plugs have a screw-on (cathode or anode, don't remember which - old-style plugs had'em - it's the silver-colored) part at the top? maybe it's not screwed on tight? and causing a loss of connection? i hope i'm not dating myself (not literally) by saying that... :roll:

good luck!
dave
 
It sounds like his plugs are fouled. By removing the wires it takes a higher voltage spark to jump the gap from wire to plug so the tip of the plug is actually getting a higher voltage spark which is a little hotter. When plugs are fouled the voltage is decreased because part of the energy is draining off through the fouled tip. Tell him to change the plugs and maybe even go to a hotter plug to prevent fouling.
 
a problem I ran into is that sparg plug wires are junk now. The old copper center wires are gone and it is some carbon junk. like all other brands he probably had to cut to fit. if you put to sharp a bend in the wire, the carbon part actually brakes. so when he took the wires off and they where at rest with no bend, the 2 broken ends touch again. which inturn gives a good spark. I would go with Bigdogs speculation first, it is the cheaper way to go.
 
Just a word of advice [My Opinion] Stay away from TSC tractor parts. Has bit me in the :censored: more than once.
 
Years ago i would purchase a roll of ignition wire and all the parts to go with it(boots / clips) but lately i can't find anything to fabricate my own wires. (on the net)

Brillman has everything....awesome....
 
Big Dog is right, I remember this from my old dirt bike days, when a plug would foul we used to pull the wire off and just set the boot on the plug as you mentioned. This would help us start the bike. I think it makes the coil create a hotter spark. My suggestion is check the condition of your spark plugs after you've run them. You might have to run another heat range hotter. Also I would check the ignition system (Clean the points, Check the gap) also is it running rich? I don't think that the wires are the problem. Is the cap and rotor good? Just my opinion...

Brian
 
I know Dave was going to be working on it on Saturday bu I didn't speak to him after he started. I'll call him tonite and see what's what. I'll ask about the cap, points and tell him to pick up some good D21's if he hasn't already. I'll keep you guys updated...
Brian
 
You guys made me curious, so I checked the NAPA web site, for bulk metallic wire. It's still available, in 100 ft. spools, 4 colors available, the part # for black is BEL 734803. I too have always made up my own wires this way. I'm not needing wire anytime soon, I still have about 3/4 roll and plenty boots & ends, but was just curious.
 
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