Briggs engine swap wiring help

I have a question regarding swaping Briggs engines, Blown engine is a 18.5 HP OHV intek single cylinder 31P777 0602-E2 in a Craftsman tractor #917.276761, the engine going in as a replacement is a 19HP twin cylinder Briggs # 42E707 2631 E1 from a Craftsman 917.270781 tractor. the wiring is different and i need to know what goes to what? the new engine only has 3 wire plug (manual choke) wires are red, orange and black. the tractor has a 4 wire with an additional red jumper (electric choke) orange, white, blue, black with white tracer, and the red jumper wire. can someone tell me what wire needs to go to what wire and what gets eliminated?

The most reliable way to know where the wires go it to take off the cover to the engine and trace where the wires go. I've seen all different color configurations on these engines.
Different engines with different configurations might have features that others don't such as a oil pressure sensor or fuel solenoid.

Take the covers off both engines and trace the wires and compare the connections between the two.

There should be a wire going to the fuel solenoid. That should get +12 when the ignition is on, so it would connect to the matching pin on the old engine. If the old one didn't have one, you will have to run a wire to the ignition switch to get +12v when the key is set to RUN. See which pin on the connector gets +12v.

There should be a wire going to the ignition coils. That should connect to the same pin on the connector as the other engine. Usually it is a black wire.

There should be wire(s) coming from behind the flywheel. That is the alternator wires. If there are two wires that are the same color, it needs to be connected to a voltage regulator. The voltage regulator mounts to the outside of the engine and has three wires; two yellow and one red. The two yellow wires connect to the alternator. The red wire gets connected to the pin that the alternator connected to. If the alternator only has one wire, it can be directly connected to the pin where the old engine's alternator wires were connected to.

There might be an oil pressure sensor on the engine that might use one of the wires. If the old engine did not have a low oil sensor, then the wire will be unused.

Some engines have an extra ground wire. Use a multimeter in continuity mode to check ground connections.

twinfords said:

I have a question regarding swaping Briggs engines, Blown engine is a 18.5 HP OHV intek single cylinder 31P777 0602-E2 in a Craftsman tractor #917.276761, the engine going in as a replacement is a 19HP twin cylinder Briggs # 42E707 2631 E1 from a Craftsman 917.270781 tractor. the wiring is different and i need to know what goes to what? the new engine only has 3 wire plug (manual choke) wires are red, orange and black. the tractor has a 4 wire with an additional red jumper (electric choke) orange, white, blue, black with white tracer, and the red jumper wire. can someone tell me what wire needs to go to what wire and what gets eliminated? View attachment 7028

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Go to the sears web site & download the owners manual for both mowers.
There should be a wiring diagram in each of them.
The other place to find the wiring diagram is in the parts breakdown.
They are all up there.

There is no such thing as an electric choke on a mower.
The thing on the bottom of the carb is a fuel shut off solenoid & must be energised for the engine to run.

Arwing64 gave you some good advice.
The other thing to watch is the magneto kill wire do not connect it to the coils till after the wiring is done and you have run the engine.
Triple check there is never ever have any battery voltage going through that wire or you will fry the trigger chip in the coils & wreck them.

There are wiring diagrams in this BRIGGS Alternator manual, they should be helpful,


http://www4.briggsandstratton.com/miscpdfs/RNT/alternator_replacement.pdf

AWWW SHOOT.... did it again, this post is 7 yrs old...

Boobala said:

AWWW SHOOT.... did it again, this post is 7 yrs old...

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Not to worry, Big Guy, I just got here and you saved me.

Thanks.

Many members (including myself) have asked for a marker of some type, so someone with an issue, could display whether or not their issue (question) was answered or not, many of us have replied mistakenly,to an outdated, unanswered post....... :confused2:

bertsmobile1 said:

Go to the sears web site & download the owners manual for both mowers.
There should be a wiring diagram in each of them.
The other place to find the wiring diagram is in the parts breakdown.
They are all up there.

There is no such thing as an electric choke on a mower.
The thing on the bottom of the carb is a fuel shut off solenoid & must be energised for the engine to run.

Arwing64 gave you some good advice.
The other thing to watch is the magneto kill wire do not connect it to the coils till after the wiring is done and you have run the engine.
Triple check there is never ever have any battery voltage going through that wire or you will fry the trigger chip in the coils & wreck them.

Click to expand...

Kohler is using an electric stepper motor actuated choke on some of their new engines. it is controlled with a box on the side of the blower housing similar to what was used with the old SAM type module. There have been some minor starting issues when warm engines because when the key is turned on the system goes through a full choke close self test, and if you attempt to start within the first two seconds of key on will attempt to start the engine with the choke closed on a warm engine causing flooding.

Thank you sir .
I stand corrected