2 cyl wisc

On my friends 2 cyl wisc eng the little round distributor cap has 2 sparkplug wires next to each other. I'm thinking they should be on opposite sides. What am I missing?

That is the same way the cap on my 2 cyl wisc looks , both plug wires are side by side
, other side is blank.

For a 2 cylinder engine to fire 180 degrees apart the pistons need to be at TDC at the same time. By having the plug wires next to each other, they fire in sucession then there is a couple blanks while the rotor comes
around for exhaust and intake strokes. The other way it can be done is to have the rotor turn at engine speed, with evenly spaced wires on the cap, and the plug fires every time the piston is at the top, compression
or not. Many of the 2 cyl. JD are this way.

That engine can be built in both even and odd fire configuration, I have both. One is on LP gas, both pistons are at TDC the same time, is even fire like Onan opposed twins are. TJD engines run like JD two cylinders do, after one fires, crank turns 180 for two to fire, then crank turns 540 before one fires again. Parts changed are crank, cam, and ignition all together for a given engine. The old Large air cooled Wisconson book section shows it best.

I didn't know that. Is there some serious counter balancing on the engine with both pistons travelling together?

The parts book I have is not really clear in the photo section, and I've never had each type crank out to compare the two. If I recall one design does not have the upper speed limit as high. Now I'm curious if the same rods are used on each crank, will dig the parts book out later and check.

In a 4 cycle engine where the pistons fire 180 degrees apart the pistons are on opposite throws of the crank 180 degrees apart. Number 1 fires at or near TDC then the crank rotates 180 degrees and number 2 fires at it's TDC, then the crank rotates 540 degrees before number 1 fires again. This is known as "staccato" firing order....like John Deere 2 cylinder engines operate. Two cylinder 4 cycle engines with both pistons on the same crankshaft throw that fire on alternate 360 revolutions of the crank similar to British 2 cylinder motorcycles and the early 30-60 model E Rumely tractors are "alternate" firing 2 cylinder engines. The alternate firing engines run smoother than the staccato,firing engines, but require substantial counterweights on the crankshaft to offset the imbalance of both piston/rod assemblies being on the same single throw of the crankshaft. The trade off is the staccato firing engines usually require a larger flywheel to dampen the pulses of such an uneven firing order. The exhaust note is different.....John Deeres p-putt, huff, huff, p-putt, huff, huff, the even firing engines putt, hutf, putt, huff when idling slowly. (I think I got this right).

Yes, they have a large counterbalance on the crank, I had a couple of older Triumph motorcycles that were like that, they ran well at 7000 rpm! Now I have a much newer Triumph 2009 865 twin, and I'm not sure how it is set up, very smooth and powerful!

Sorry, brain sneeze... I got the wrong number of degrees in a circle!

Distributor or mag? With the mag, both plugs fire on every TDC but only one is on compression. On the even-firing type (TF, TH) there is a large counterweight between the throws. Oil pump and pushrod is offset to one end rather than in the center.

(quoted from post at 13:24:21 10/24/16) Distributor or mag? With the mag, both plugs fire on every TDC but only one is on compression. On the even-firing type (TF, TH) there is a large counterweight between the throws. Oil pump and pushrod is offset to one end rather than in the center.

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The engine is a TJD and we have the head and the pistons are 180 degrees apart. The intake and exhaust valves work as they should. The engine had a cracked head that started at sparkplug hole and went about 2" toward combustion chamber and then stopped. He had it TIG welded but it didn't hold.

Had a blown head gasket and the pistons are 180 deg apart.

It would run without a distributer . Just use a dual output ignition coil such as used on a snowmobile .