Super M won't start

[Drifter52]

It has been changed to 12 volt system running a coil instead of a mag. Was running along blading the drive and opened throttle some it popped and died. Saw a bunch of crude in the sediment bowl. Dumped it and opened the drain vale. Just a drip coming out. Went to pull bottom of carburetor off and found must take out the fuel inlet with screen to remove back bolt. This was plugged solid with fine debris. Dropped bottom off to find more crude floating. Used carburetor cleaner to flush all jets and orifices out and saw it go through each. Put back on with new gasket still no go even with either. You can feel both suction as well as pressure when cranking with hand over the inlet to the carburetor. I bought this from a man several months ago and had run it with no problem.

I did change out a ignition coil and resistor earlier as the resistor had burnt off. I checked spark and shows a strong but yellow color spark. I reset points to .020 and installed new rotor and cap as well. Plugs will be my next step but want to make sure which plug and see if I am heading down the right track. The PO said he did a complete overhaul on it a few years back with less the 100 hours on it since.

What is valve lash set at on these? Maybe too tight on an intake valve causes the back pressure?

 

[DJ54]

.017 hot on the valve settings.

Being everything was filled with crud, did you remove the discharge nozzle out of the bowl,and make sure it was good and clean..?? Those cross drilled holes will plug, not allowing fuel to be pulled up through the venturi.

 

[Drifter52]

I sprayed back through the brass tube that goes up inside and had good flow. There was more that came out of there once did that as well. Now when crank it over if choke it without breather tube attached it sprays back gas. There is no tab on this model float to be able to adjust. When took it apart early the hinge pin of the float had vibrated out. I saw no hair pin clip in bowl when dumped it. No groves on pin either so no idea what locks it into place. I had thought about squeezing the clip it rides in to try to keep it in place but didn't.

 

[DJ54]

The center tube isn't what plugs. It's the tiny cross drilled holes in that tube. You need to remove it, then take something like a single wire plucked from a wire brush, or a strand of wire from automotive type wire, to clean them. A spritz of carb cleaner, then blow with air. Hold it up to the light, and make sure they are clear.

I don't know that there is a keeper on any of my smaller model tractor engines. Once the bowl is back on, the pin can't slide far enough sideways to come out.

Have you pulled the valve cover..?? Sounds like a valve hanging up, if it's blowing that much compression back through.

 

[Drifter52]

I held my thumb over the outlet while shooting the cleaner into the end. I saw cleaner coming out of the small holes on the side also reversed direction while covering the end of the brass tube as I found if not cleaaner will hit you in the face. I am figuring to pull valve cover tomorrow to check for a hung or tight valve. #3 cylinder seems to have a wet trail from the plug going down and out to the sides as well. I plan to pull plugs to check condition. Also noted a couple cracks in the exhaust manifold on either side of the stack.

 

[Drifter52]

I held my thumb over the outlet while shooting the cleaner into the end. I saw cleaner coming out of the small holes on the side. I am figuring to pull valve cover tomorrow to check for a hung or tight valve. #3 cylinder seems to have a wet trail from the plug going down and out to the sides as well. I plan to pull plugs to check condition. Also noted a couple cracks in the exhaust manifold on either side of the stack.

 

[Drifter52]

Real bad news. Cam not turning now. None of the valves are moving once pulled valve cover.

 

[DJ54]

Ouch... It could be possible with the recent overhaul, if it was a complete one, and they replaced the cam bearings, one or more may have spun, seizing the cam, and shearing the woodruff key on the cam gear. If you didn't hear any clatter when it shut down, is probably good news. Like in pistons slapping valves. At this point, believe I'd pull the side inspection cover, and check for bent push rods.

No matter what you find there, you're going to have to pull the engine, pull the front cover, and have a look see.

 

[Drifter52]

Was just a pop as in like a backfire when she went down. Was down close to an idle. Hate to open an engine up where it sits now as is a sand road. This has the live hydraulics so the pump is run off the crank or cam gears to my understanding anyway. A locked up hydraulic pump could of caused the problem. Really don't need another project at this time.

 

[Drifter52]

No alternative with the resources here but to try to fix the old gal. Got the water pump and bottom radiator hose off along with the tin work. Crankshaft nut feels like someone used a chisel to tighten it. No room to get a socket or wrench on unless they made a special wrench. Any help would be greatly appreciated.I looked at the block the radiator sits on and it appears to me if take those bolts loose the front wheel assembly could seperate. I have no way to split this old gal where she sits.