Troy Pony Engine Replacement

Kolchak

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Yesterday, I received the bad news that the engine on my mower had locked up (threw a rod?). Had someone check it out, and they told me that I'm faced with the option of either replacing the entire engine or buying a new mower. I don't know much about this kind of thing, so I'm asking for honest help from you guys. Is it worth replacing, or should I just get a new or used one? What model (etc) engine do I need to buy (links VERY welcome) if I replace it? My mower is a Troy Pony Model # 13WN77KS011, and I've had it for about 9 years.
 

Scrubcadet10

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We'll need the engine Model numbers. Should be stamped on the metal OHV cover on engine.
Main things when repowering equipment is,
Engine Horsepower, never go less than the original.
Crankshaft Length and diameter.
Charging system and wiring. (Which we can help you with on here)
from looking at the mower diagram the motor looks like one of these two, but that's just a guess.
 

Kolchak

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Thanks for the fast reply. Here's pics of everything on the engine.
Resized_20200702_114911.jpegResized_20200702_114107.jpegResized_20200702_114034.jpegResized_20200702_114008.jpeg
 

Scrubcadet10

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Okay, a simple google search brings that exact engine up on Ebay and other stores, I just typed in Powerbuilt 17.5 HP 500cc engine.
But to be sure give the model number of the engine to be sure there aren't any variations in dimensions. Should be stamped on the metal OHV cover on front of the engine, by the spark plug
 

Fish

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Buy a new tractor,
sell the old one for $100 or so.
 

Kolchak

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Okay, a simple google search brings that exact engine up on Ebay and other stores, I just typed in Powerbuilt 17.5 HP 500cc engine.
But to be sure give the model number of the engine to be sure there aren't any variations in dimensions. Should be stamped on the metal OHV cover on front of the engine, by the spark plug

Posted this 4th pic when I edited my previous post. Probably didn't go through as you replied. This what you need?
Resized_20200702_114911.jpeg
 

Kolchak

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Another problem encountered: We replaced the engine with a model 31R907-0006-G1. The old engine had a dual circuit alternator system. The new engine has a 9 amp regulated alternator system. We reused the wiring harness from the original engine, which was also a B&S 310000 series engine so it should use the same wiring harness. The killswitch and the fuel solenoid wires plug in exactly in the same spots as on the old engine. We needed an adapter for the alternator and after doing some research found that this should be B&S part number 790544. We used this adapter to hook up the alternator to the original wiring harness.

However, when we reconnect the battery with the ignition in the off position and the seat up, the headlights immediately come on. They stay on when we turn the switch to the on position and stay on when we turn the switch to the off position. We tried another wiring harness for a 400000 series engine (with the kill switch wire in the same place as on the 300000 wiring harness) but no change. Not sure if this means there is something wrong with the kill switch on the engine, or something else. Help?
 

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Kolchak

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(girlfriend here)

OK, so after doing some more research I think I have figured this out. The old engine was a dual circuit, so there was a DC wire that charged the battery (red wire on the pictured harness) and an AC wire that powered the lights (orange wire). The new engine is a 9 amp regulated system, so it has one DC wire coming off the alternator to charge the battery, but no separate headlight wire. The adapter I bought takes that one wire and connects it onto the mower's wiring harness to charge both the battery (red) and power the lights (orange). There is no separate switch on the mower to turn the lights off and on, so I guess this means with the new engine the power to the lights is always on. The B&S wiring diagrams seem to confirm this, as the wiring diagram for a dual circuit system does not have a light switch, while the wiring diagram for the 9 amp regulated system does have a light switch.

So...if I'm understanding this correctly, it looks like my options are to take out the light bulbs, disconnect the spliced wire on the adapter so the orange headlight wire no longer gets juice, install a light switch so the headlights can be turned on or off at will, or disconnect the battery when the mower is not in use. For the time being I think we are just going to disconnect the battery until we figure out what to do in terms of snipping wires and such.
 

Fish

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Just swap the flywheels and alternators.
 
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