on the gasket paper yes. just around the edges.

Trainzkid88 - Roger that.

Ok I'm back up with the dozer for a couple of nights again. I've reinstalled the starter motor and (despite the second new solenoid I put on the starter intermittently failing and going open circuit) I have a starter that runs reliably.

However here's the next problem: when the drain cocks on the pony motor cylinders are closed the starter motor won't turn the pony motor a full revolution. Very disappointing since it's running on 12 volts and should have heaps of power. I checked the continuity of the windings when I had it apart and it all looked good, so that's a mystery.

So I've walked away to have some lunch and have a think about it.

I tried to retime the magneto (following the instructions here: www.acmoc.org/bb/discussion-d72/29052-ti...rting-engine#gallery). However the pulley on the back of the pony motor doesn't have a timing mark. And my magneto only has one timing mark, so it's really only a little better than guessing at this point.

Very frustrating.

On the up side, there is fuel getting through the carburettor to at least one of the cylinders (No. 1/left hand cylinder) of the pony motor, so sitting for three weeks with fuel in it has loosened up the junk in the carburettor a bit.

Back to the basics -
I do not remember which cylinder is Number one - if #1 is on the left side as you sit in the seat looking forward -
Remove the spark plug from #1, put your thumb over the hole and pull the flywheel over until you feel compression. (dont be confused by slight pressure on exhaust stroke) You can use a wire inserted into the cylinder to determine TDC within reason. (Piston will push the wire out of the hole until it reaches Top Dead Center, as the flywheel continues to roll the wire will retreat into the cylinder. (you will hold the wire so you can feel this movement.) Timing just past TDC will not hurt but much beyond will affect the power outcome.

Once TDC has been determined, set your mag timing and install. This should put you close enough to get it running.
TIMING IS CRITICAL - must have spark within a few degrees BTdC or just after TDC on the compression stroke. If not, you can pull on a rope all day long or push the button on the electric starter with no positive results. (timing marks make this an easier installation but are not necessary if you follow the basic rules)

You state - Fuel is getting to #1 - do you mean fuel has filled the cylinder - liquid is present?
If you choose, mix some gasoline and motor oil, shoot directly into the cylinders with spark plugs removed. The Oil will help lube the piston and raise compression a bit, gasoline will be ignited by the spark plug. (Old trick used on early gas cats that were tired, not much compression)

Just a word of caution -- if you are using a rope on the flywheel, DO NOT WRAP THE ROPE AROUND YOUR HAND!



CTS

CTS - thank you, I figured out the TDC for the left cylinder which I assume (based on the instructions is No.1) pretty much how you described.

But I'm just guessing with the magneto timing. As mentioned, the only mark on the non-rotating part to align the rotating part with puts the rotor on the front way out of position (like 90 degrees out).

Another development since lunch, I ran the starter on the pony motor with the stop-cocks on both cylinders open and was rewarded with a "pop" from cylinder No.1 (and no kick-back). So at the very least we can say there is spark and fuel in that cylinder.

I'm going to have to get the starter looked at though. It's just gutless and won't crank the pony motor over past a compression stroke when the stop-cocks are closed.

ignition timing on most engines is set advanced so before TDC. this is done to allow time needed for the flame to propagate through the combustion chamber and this burn all the air fuel mix and make power.

to set at or after tdc is considered retarding the timing. it can also make a engine run hot and it isnt a good thing as that can cuase other damage. to much advanced is also bad.

many stationary engines can be ignition timed by using a bit of stiff wire or a thin screwdriver to feel the piston reach tdc and then roll it back so the probe goes back in about 4 or 5 mm
and setting the points to just open then. and that gives around 7 degrees advance. find the compression stroke first!
make sure you have the plug wires in the right spot too i learnt the hard way ours wouldnt fire the suggestion was made to swap them at the mag and away it went.

Trainzkid - thank you for the explanation frankly I'm lost at the moment. I managed to move the dashboard plate enough to finally spot the marks on the fly wheel. One is MAG, the other is EX C? (where the ? Is not really legible, might not even be a character.

This isn't a great photo, but you can just make out the MAG mark at the top.

 

The MAG mark is well off TDC for cylinder No.1 (or the other cylinder) so I'm going to have to research and find out what the actual exact timing procedure is for the D6 8U with this magneto because I cannot figure it out myself.

I tried the wire down the spark plug hole trick, but weirdly only got a little bit (like 5mm) movement out of whatever it was touching inside - which should be the piston face - when I turned the flywheel. So I have no idea what is going on in there.

I'm not trying to change the angle of the rotor on its shafts, because - I assume - it was correct when I pulled it off and it's just a matter of getting it back the way it was...

Currently it's beyond my knowledge to resolve.

You may not have a clear shot to the piston through plug hole. Not sure if the top or middle plug heads are better for getting to the piston. Sounds a bit like you're feeling a valve with your wire.

Paul.

Paul - yes it had me in mind if a value too, but I don't know enough about the internals of that pony motor and that didn't seem right, but it clearly wasn't the piston top.

Retarded vs Advanced
When one retards the spark (timing) it delays the firing until the piston is on the power stroke beyond TDC
Advancing fires the plug before the piston reaches TDC on the Compression Stroke.
Too Far advanced will end up in severe kickback - many have learned that lesson with bodily harm.

Flywheel in your photos --- clean it up so you can see the marks easily, there should be a pointer that you will line up - if you can not find the pointer, broken, missing , you will resort to finding TDC. Again, ensure #1 is on the compression stroke, not exhaust! Compression stroke - both intake and exhaust valves will be closed.

EX CL is most probably EXHAUST VALVE CLOSES

Two suggestions re: magneto timing --- make sure you follow the instructions when setting the mag itself -- remember - the magneto "fires" the instant the points open and break the circuit. 2-- ensure you have the wires from the mag going to the correct cylinders - both of these items are imperative - must be correct.

You should be able to feed a wire into the cylinder - if there is very little "stroke" you are not reaching the piston.

RE: Electric Starter --- nice feature, not necessary to have operational --- I suggest you work toward getting the Starting Engine Timed and running before you spend $ and time working on an "accessory"..

Again - if the goal is to find out if the Diesel will run - you may resort to my suggestion earlier of using a known power source belted to the starting engine. May not be "KOSHER" but it has proven to be an option over many years. You will want to ensure the Starting Engine does not have issues before powering this way, if the starting engine is mechanically compromised, you will only compound the damages.

CTS