Timein' CUB continuein' SAGA

I pulled the side cover on the engine , got both lifters as low as They go (#1 cyl,), few more degrees the crank pulley mark and the pointer line up....back at #4 one lifter is up , the other down so My way of thinkin' # 1 is TDC and ready to fire . Placed rotor aimed at the coil wire hole,started #1 wire there and ran the firein' order out from there , clockwise same as the rotor turns , As per the book , turned the dist. as far toward the engine as possible , turned the engine 2 complete revolutions , turn the dist. CW away from the engine until I heard the impluse click....Was expectin' the engine to run but backfire is all I'm gettin'....Turnin' the dist. to different points in the adjustment range doesn't help....Does backfire mean the time is too far advanced? Should I move the rotor a gear hole counter clockwise , or maybe clockwise , I don't know at this point I'm as confused as a termite in a YO YO....On the impluse couplin' end I didn't see any marks as to whether the part linein' up with the driver had to go in a certain way....Now I wonder if I should bring # 1 to TDC pull the dist. turn the couplin' 180 , and start all over again...My thinkin' has always been if #1 is TDC , both valves are close , You can start # 1 where ever the rotor is pointin' and it is timed close...Never knew it to fail untill now....So have I went at this wrong , any body see where I'm missin' up....Any hints or clues would be greatly appreciated
Thanks,
Wild Bill

#1. Before pullin the distributo and turin' it 180, try swapin' the wire s to see if that's the problem. Simpler solution to the problem.

My other thought . . . At TDC on #1 compression, yes, both valves should be closed, but so should both the valves on #4. You may have a valve timing problem.

It will not hurt to put the plug wires in 180 degrees from where they are (just to see !!)
Valves that are not set correctly, or an intake valve that has a little chip of trash under it, will backfire. Make sure the valves are set cold.
Jim

You are observant! They should be very close to closed, but there might be some overlap. (I do not know) I would not set the valves at TDC exhaust on that cylinder. But if it is noticeably open, there may be rust on the tappet, or a stuck #4 valve! Jim

Your procedure sounds correct.

Check you pulley, some have two timing marks. The first mark is the advance and the second mark to reach the pointer is the TDC mark.

The two revolutions back to the TDC mark then time the magneto.

The reason I was thinkin' I might need to rotate the couplin' 180 is the drivein' gear to the rotor has a flat that matches with a flat on the shaft turnin' the drivein' gear.....I can't find any info in the books that says where the flat part on the shaft should point , I think it can only point in two directions , roughly up ( toward the coil) or down (toward the ground )....the gear has a small protrussion on top that matches with the flat place inside the gear that fits on the flat place on the drivein' shaft....This tractor hadn't ran in several years , I had it runnin' , fair , knew it needed points , since the dist. lays in horizontal I thought it would be easier to set the points and clean everything up if I had it out and on the bench. I might have turned the engine over (not thinkin')or who knows what At any rate I've went to TIMEIN" school on this one...guess it is schoolin' I needed.....Once I get it runnin' I'll set the valves...As it is now one lifter ( I'm not handy to the tractor now ) I think it is the exhaust , starts to get up against the vavle an is no longer free at around 32 degrees before TDC but as near as I can tell doesn't start openin' untill past TDC ...at this point #4 will have one lifter up , one down...By the way , this is a magneto dist. When I get this one straightened out , I've got to put points in a 1956 Cub...You can bet I'll go at that one more careful
Thanks
Wild Bill

All the timing information you'll need (for the rotor-to-mag and mag-to-engine) can be found at the link below.

Look at Pages 4 and 5.

You'll have to copy it and paste it into your browser as this site does not allow the posting of a direct link.

http://www.cleancomputes.com/Cub/Blue%20Ribbon%20Service%20Manuals/GSS-1012%20Electrical%20Equipment/index.html

P.S....

It's not necessary to call it a "magneto dist".

It's simply a magneto, an IH Model J-4, if it's what's supposed to be on there!

You need to pull No1 plug and bring No1 piston to TDC on the compression stroke. Hold your thumb over the plug hole while someone hand cranks the engine until you feel pressure against your thumb. Have them keep cranking the engine while you keep your thumb over the plug hole until the pressure stops, then see if your timing marks are aligned. If they are see where the rotor is pointing on the mag. If its not at No1 plug tower you need to pull the mag and rotate the rotor to No1. Should be in the 1 & 2 o'clock area. Hal
2-1
4-3

I have it Bill.
Your problem is that you are not on TDC with #1.
During the compression and power stroke the valves are both closed all the way through at least 95% of both strokes, and thus #1 cylinder cannot be at TDC after compression if there is a valve starting to think of moving within 90 degrees of that spot. on a cub the piston is not clearly visible through the spark plug hole, so the thumb procedure (mentioned below) is important. Then align the timing mark and rotate exactly two turns to the correct timing mark and set the Mag to click. good luck Jim