49 B timing?

Quote:-� if i run the left cylinder up to tdc the rotor is not on the post for that cylinder it is half off�

--That could be normal,, to there could be a problem,, depends on how far off at static & how far off when running..

First thing�Line the flywheel L/H impulse & case mark back up then grab the distributor rotor with your hand & take the play out in the backwards direction.. See how it lines up then.. If better, suspect distributor wear or sticking advance weights, or even a distributor shaft problem..

It might even be your base starting timing is off a little..

To check the starting timing--- Remove the L/H spark plug,, then leave it in the wire & lay it on the engine block,, then crank the engine over with the ign switch turned on,, you need to see that L/H plug spark as the L/H impulse mark on the flywheel lines up with the case cover mark (at 3 o�clock directly behind the flywheel & even in height with the center of the crankshaft,, open flywheel) OR, when the depressed dot on the flywheel hub lines up with the dash mark on the bottom center of the flywheel cover�s center hole (covered flywheel)..

Make sure your points gap is set correctly as that also effects the timing .015� for the Wico dist & about .021� for a Delco (round cap) dist..

If it runs your rotor is probably lining up ok.. That rotor placement (line up) has no effect on the spark (ign) timing,, timing is strictly related to when the points open)

Clooney

If the flywheel is on the correct spline,,,,, ,,and the crank to cam AND cam to Governor are ALLLLL LLL in time,,,,, ,,when the Left Piston is at TDC, the Flywheels Left Hand Impulse timing mark is at 3 o clock lined up with the flat mark on the tractors side,,,,, ,,,,, ,,and then,,,,, the female slot (which mag drive fits into) SHOULD BE FLAT HORIZONTAL FORE N AFT.

IF NOT, either the timings off somewhere (likely the governor to cam) or else theres a problem in that hydraulic pumps in and out timing, but I dont recall how they can be wrong.

To repeat the timing I posted below, get the left piston at TDC which should be when flywheels LHI is at 3 o clock,,,,, and the pump/governor female drive slot should be flat horizontal fore n aft,,,,, ,,and the points should be just breaking open on the leading cam lobe and the rotor tip lined near the caps leading tower to fire the LEFT cylinder, then 180 later, points break open on lagging lobe and rotor tip is at lagging cap tower.

IF SHES NOT LIKE THAT, I SUSPECT THE GOVERNOR IS OUT OF TIME TO THE CAM GEAR OR ITS THE WRONG DISTRIBUTOR CAP!!!!! !!!!! ! If the female drive slot is the flat horizontal fore n aft as I described (at left piston TDC),,,,, ,,,then the governor to cam timing is CORRECT,,,,, ,,,so that leaves an incorrect cap or its mounting!!!!! !!

John T

If the start timing fires her way too soon BEFORE the piston reaches TDC on its Compression Power Stroke, it wants to kick the flywheel backwards, but if too slow, she can be harder to start.

START TIMING

Assuming its a Distributor as you say, I would remove the plugs for easy cranking,,,,, ,,,loosen the distributor bolts and retard its timing to the max forward CW position,,,,, ,,,rotate the flywheel to get the left piston at TDC which is when the Flywheels Left Hand Impulse timing mark is at the flat mark on the tractors side at 3 o clock,,,,, ,,,,,have the ignition on and the plug wire to the left plug 1/8 inch away from tractor to observe a spark,,,,, ,,,slowlyyyyy yyyyy advance the timing by slowlyyyyy yy rotating the distributor rearwards CCW UNTIL THE LEFT PLUG OR PLUG WIRE FIRES and tighten her down.

If all is correct and in time and as she was original,,,,, as the distributor shaft rotates and the points break OPEN on the leading cam lobe, the rotor tip is lined up with the caps leading (top) tower to the LEFT piston,,,,, and then 180 of crank/flywheel/governor rotation later,,,,, ,the points again break open on the lagging cam lobe and the rotor tip is lined up with the caps lagging (lower) tower and it fires the right cylinder.

The only way to tell for sure when shes firign is by use of a timing light, but this will get you in the start timing ballpark.

You could also have a carb problem, but see what the start timing is like and try n adjust the carbs idle n load screws and INSURE THE POINTS ARE CLEAN AND GAPPED AND NOT BURNED OR PITTED OR CARBONED UP AND HAVE FRESH CLEAN WATER FREE GAS AND INSURE THE AIR BREATHER CUPS NOT FULL OF WATER AND TRY FRESH NEW PLUGS FIRST as those can contribute to poor runnign or backfiring etc also.

If the start timing is okay, I would still check the points n replace if needed and "try new plugs" and try adjusutng the carb before going much further. She may just need fresh plugs n points and a carb tweaking????

Let us know, good luck n God Bless

John T

Those distributors turn at the same speed as the crankshaft, so they spark on both the compression strokes and the exhaust strokes.

It is easy to get those engines "180*" out of time and still have some popping occur. You didn't say what brand of distributor you have, but that doesn't really matter.

If the rotor is not aligned with the cylinder that is at TDC, then you either have to switch the plug wires in the distributor cap towers or remove the distributor and turn it a half turn and reinstall it.

To be factory correct, the upper tower wire goes to the #1 (LH) plug. You could remove the distributor and turn it a half turn and reinstall, but it always seemed easy enough to me to just switch the wires.

Just switch the wires right now if you're confident that everything else is correct, and give it a try. It doesn't cost much to do that, nor to switch it back.

Frank

As long as the rotor is NEAR the appropriate terminal when the points open, the high tension spark will jump the gap to the terminal.

However, if the rotor is WAY OFF from where it's supposed to be when the points open, the cap and rotor may be mis-matched, the point gap my be WAY off, or there may be some other unusual problem in the distributor.