The string of numbers you posted IS NOT the correct Model and type numbers you need to identify the engine for parts and service information.
The numbers you posted are just the EPA certification numbers.
Search for a tag or decal with the words "MODEL, TYPE, CODE" with the corresponding numbers under each heading. It will be on the engine somewhere.

Likely stamped on the top of the valve cover IE 31c777- 1234-b1

Hello; Thanks, I'll take another look.

Try Tulsa Small Engine Warehouse for a replacement.

Walt Conner

Hello; I looked again and Found - model 31D707; Type 0458E1; code 050311ZE

Hello; Tried tulsa small engine warehouse. They sent back several options with the least expensive being just under $500. Thanks for the info, I will pass the information on to my neighbor to see what he wants to do.
I also looked at the Northern hydraulics site as we have a store in the area, about sixty miles away. They have one that seems close but I am not sure if it is a match.

Very little on any 31 series engine to not match except charging system which you could change, they interchange, but would likely void your warranty.

Walt Conner

Hello; Another question. In addition to the model, type, and code of an engine, what other criteria should be presented to a vendor to get a bolt in replacement engine?

The model and type is really all they should need. There are change over lists that are used for comparison. Like Walt said, the charging system is a more common difference. Watch that the connectors/ wire colors are the same. Some will have an external regulator, some won't. Sometimes they will have a different throttle control set up. This is typically a rider engine, but I suppose it is possible to have a different crank. According to the Briggs lookup, the shortblock is a 697761- which you might find cheap and the replacement engine is a 31N7073026, which you probably wont. If you find a deal and are unsure, post the model and code and we can compare the obvious things on parts look up.

Thanks for the information. The neighbor is going to pull the bad engine so the shaft length can be measured as that seems to be one thing the vendors want to know. Apparently there is also more than one bolt pattern. A short block might work, depending on the internal damage. It appears that the engine was run low on oil and that something gave up internally and went thru the side of the block.

Hello; My neighbor picked up a used engine to replace the blown one. It is a 17 HP twin II I/C model 42A707 type 2238E1 code 0008165A Got the engine to start and run, but we have not determined how to hook up the engine stop wireing to turn it off with the key. The setup will need a longer throttle cable and a manual choke cable will need to be installed. Any pointers on how to determine how to wire the engine stop?
The engine also has no muffler, only two exhaust pipes.

Hello; Neighbor picked up throttle and manual choke cables. Got them installed.
Engine boggs down and dies when blades are engaged. Can keep it going by quickly manipulating the choke. Did a search on that issue and will try some of the things suggested.
Will likely try experimenting with ignition engine kill wireing as it is not practical to choke it off if we get it to the point of mowing.

Engine kill wire is connected to the magneto.
You might have to pull the engine flywheel cover to determine if the wire is present on the magneto.
Some Opp Twins have the kill wire from the magneto ending at an insulated screw terminal on the sheet metal shroud where the chassis OEM will connect their kill wire circuit.
Some Opp Twins have the kill wire from the magneto running to the throttle control bracket where the chassis OEM throttle cable connects to the sliding switch.
I don't know how yours is configured but you have to GROUND the magneto kill wire to stop the engine. If you accidentally run 12 volts to the magneto you can kiss the mag goodbye and throw it away.

The bogging down is probably due to the carb bowl and main fuel jet needing a good clean out.

Hello; Thanks mownie. Have not tried the ground wire yet so will be careful.
Vent in gas cap seems clear. Took the main fuel jet out, wiped it off and reinstalled. No joy. Will try some new plugs tomorrow. After that will likely open up the carb.

Engine starts easy. Can drive in any foreward gear without bogging down. When engaging blades engine dies unless I go to full choke quickly and briefly. Once blades engaged can drive and mow without problem (At least for the 20 or so yards I tried.)
Engine starts back quickly when warmed up only if I go to full choke then can open choke all the way.

hello; Took the carb apart today and it is one of the nastiest I have delt with. A bit suprising that the engine ran as well as it did. The level of fuel in the tank had been going down the last few days without the engine being run. There was fuel in the intake manifold. Neighbor/ owner is going to look for a kit.

***"There was fuel in the intake manifold."***
If there was fuel in the intake there is also fuel in the crankcase lube oil.
In addition the the carb kit, you will also need to install an inline fuel shut off valve in the fuel hose (between fuel filter and fuel tank) and train your neighbor to keep that valve cut off except when the engine is actually running.
And change the oil and oil filter (if it has one) before operating the engine............after you install the inline cut off valve.

Hello; Thanks for the advice. I did mention that the oil needs to be changed, but will repeat the warning.

Just for the info for you guys, I recently swapped an old 18.5 h.p. L head twin out for a 24 h.p. Twin Intek, only had to swap out the charging system, which interchanged nicely.
The 18.5 l head runs the big 50 inch deck electric pto/
hydrostatic trans just fine.

Fish

Hello; The carb rebuild seems to be a success. Still have a few issues to tackle. i printed out the post about finding the wireing for killing the engine with the key. That needs to be sorted out before the mower can be used. It is not practical to choke it off. It no longer dies by engaging the blades.