Distributor

I bought a tune-up kit for my 1952 8N and installed all the parts. I am still not sure I"m getting spark, and I wonder if I"ve put the points in wrong. I assumed the contacts should touch when closed, and the .020-inch gap I see recommended is the gap when they"re open as far as they go. Is that right? How precise does this gap need to be, and how can I check it?

Second question - I"ve been told to check for spark by pulling out one of the plugs and laying it on the engine block. Even when my tractor was working I could never see a spark when I did this. Exactly what part of the plug should be making contact with what part of the engine block? Is the fact that the engine block is rather rusty maybe the reason I never see a spark? Or possibly this must be done in dim light?
 
The CORRECT point gap for a 1952 8N is .025".

When using a spare sparkplug to check for spark, ground the metal "shell", just as it would be if screwed into the cylinder head.

The spark should be "hot" enough to be seen in daylight and should be able to jump a gap of 3/16" or so.

Is this tractor still 6 Volt?
 
Thanks Bob. This tractor is converted to 12-volt with an alternator. And apparently I've been grounding the spark plug correctly then.
 
you might have a bad wire harness.. or a resistor and old coil in your conversion... if so.. do yourself a favor and get a real 12v coil like a napa ic14sb

oh and correct that breaker gap to .025 like bob mentioned..

soundguy
 
Plug needs to be well grounded to the block - suggest you polish the rust off and try again - as others say, should exhibit a "snappy" blue white spark if everything upstream is working.
 
You check the point gap w/ a blade type feeler gauge. If you can't get the gap open to .025 (not .020) then you have a junk set of points or you don't know how to set them.

Quality parts are critical to longevity. Having learned the hard way, I most always use Blue Streak brand points. They are made by Standard parts & available at many auto parts stores. (frontmount points also fit a 48 Ford as I recall) Beware of sticker shock: $16-18 a set. My next choices are Wells or Echlin. Look for a brown rubbing block. Unfortunately, many folks have experienced problems w/ points made by Tisco, Sparex, A&I Products and any TSC ignition parts.

Correct points installation & gap is also important. Close only counts in horseshoes & hand grenades. Make sure the blade is at a perfect right angle to the points & you want to feel just the slightest bit of drag when you pull the blade through the points. Make sure the blade is clean & that you dress the new points by running some card stock or a piece of brown paper bag through them. Gap is .025 on the sidemount on all four lobes of the cam. Make sure the points align correctly.

Good hold-down screws are important. (tip # 37) If the heads are wallowed out, what do you think the threads look like? You can use machine screws as temporary replacements, but you should use the OEM Fillister head screws. The larger head is there for a reason. If you do use standard machine screws, make sure they aren’t too long & interfere w/ the advance weights. Always use star washers under the screws.

Timing is important not only to engine performance but points longevity as well. Make sure you set the point gap before you set the timing. Timing a sidemount is pretty straight forward; it has marks on the flywheel.

The next trick to points lasting a long, long time is annual maintenance. (tip # 40) No matter how well it's running, pull the distributor (or cap for a sidemount), check the gap & put a dab of points lube on the cam. Not bearing grease or Vaseline; use the correct lube.

There are ways to check for spark that work & ways that don't. Some folks think that checking for spark means pulling a plug wire off & looking for one. Well, it's the distance the spark jumps at the plug that gives you the info you want. It takes about 17kv to jump a 3/16" gap & 22kv to jump ¼” in the open air, so that's why you need to use a spark plug. Or, a store bought plug checker. (on the left in the picture) Remember, it’s 14psi outside of the engine & about 90psi at a 6:1 compression ratio in the cylinders & compressed air creates electrical resistance, so you really need the 17-22kv to fire the plugs when the engine is running.
DSC02519.jpg

50 Tips
 
Yesterday's Tractor Forums

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top