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Discussion Starter · #1 ·
Does anyone in the forum have experience repowering a 318 with a B&S 23HP engine? All is going well except
the wiring interface between the tractor wiring and the connections to the new engine. A wiring diagram for the tractor would be a huge help but have yet to locate one.
 

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From tech manual TM1590, here's your wiring:
784864

You'll also need wiring info for B&S engine. You may have some "extra" connections from tractor or may have to add wire/switch for engine. If magneto type ignition 0n B&S, you'll need to add a kill switch as I don't believe your present ignition switch has a terminal to ground. Also check for fuel solenoid as you may need to power that also! Get EXACT B&S model number, search online, and you may get lucky and find engine wiring. You may have to contact B&S to see if they can supply info.
All I've got! Bob
 
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Discussion Starter · #3 ·
From tech manual TM1590, here's your wiring:
View attachment 784864
You'll also need wiring info for B&S engine. You may have some "extra" connections from tractor or may have to add wire/switch for engine. If magneto type ignition 0n B&S, you'll need to add a kill switch as I don't believe your present ignition switch has a terminal to ground. Also check for fuel solenoid as you may need to power that also! Get EXACT B&S model number, search online, and you may get lucky and find engine wiring. You may have to contact B&S to see if they can supply info.
All I've got! Bob

Your very kind, thanks so much!!

bartles
 

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Many of us are only here to help...so we do! A "REAL" thanks will be a picture with the new engine installed and you commenting, 'It runs great.' Bob
 
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I don't feel qualified to tell you exactly how to do this, but my 23 Vanguard came with a relay attached to the engine with wires marked as to where they attached to the 420 wiring harness. This 420 had the B model Onan engine which has battery (12V coil/points/condenser) type ignition. If I understand it correctly, the 12V wire coming from the key switch in "run" and "start" positions leading to the coil/points, opens the relay to unground the Briggs magneto ignition. Turning the key off lets the relay ground the Briggs ignition to stop the engine.
With a P model Onan, and electronic ignition, it may be different. So you should let us know which Onan model your tractor had before the repower. That way the fellows here that really do know how you should wire it can answer correctly.

Not the best angle but the relay is attached to the cylinder shield just to the right of the fuel filter. Wires are still a jumbled mess, aren't they?

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tommyhawk
 

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Discussion Starter · #7 ·
Many of us are only here to help...so we do! A "REAL" thanks will be a picture with the new engine installed and you commenting, 'It runs great.' Bob
Well here's a picture of a real happy guy....just turn his key switch and the engine started!!!
Thanks so much for the diagram and all the assistance...a great forum for sharing.
 

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