20 hp Engine swap, help needed!!!

[Dhunter0047]

Purchased a John deere gx345 which got a engine swap with I believe a 20 hp briggs intek engine and I have 2 major issues I need figured out.
1. Can not get it to charge a battery. Starting and driving around it does fine but as soon as pto is engaged it starts losing power. It has the red wire with diode and black wire from stator. It will only maintain around 12.8 to 13 running full throttle no load and drops to 12.4 when pto engaged.
2. It will not start on its own. I always have to pour gas in carburetor to get it to start then it'll run fine, and you can usually shut it off and restart after that for a bit before you have to gas it again.
Any help greatly appreciated!

 

[Scrubcadet10]

#2,
I'd check to be sure that the choke is closing all of the way,
Put it in the choke position, remove air filter, and take a peek, note which way the butterfly turns to open and close, and press the opposite of the valve to check for play indicating it could close some more.

 

[Fish]

Was the wiring from the stator identical on both engines?

 

[bertsmobile1]

The 20Hp is from either a walk behind or a mower with a manual PTO.
The alternator is not powerful enough to recharge the battery and drive the electric clutch.
IF you still have the old engine swap the alternator stator & regulator rectifier

 

[Dhunter0047]

These GX345's are "garden tractors" and factory had a kawasaki liquid cooled engine. I got it from my father in law for $300. When he ran it he used a deep cycle boat battery and charged it every so often.. I have a identical engine that came off a craftsman lt1000. What should I look for when trying to swap to a better regulator and stator

 

[bertsmobile1]

Briggs put out an "Alternator repower guide" they are all over the web.
Download one & read it.
All B & S rotors are swapable and you need the regulator / rectifier for that stator.
With multi power rated alternators ie, 5 / 9 amp the smaller number is for small magnets & the bigger number is for the big magnets .
Usually a mower repair shop will have boxes of good used ones from mowers that have thrown a rod or counterweight through the crank case.
New they are not cheap and the cheap ones on Ebay / Amazon are all trash and rarely last a season.
After market ones from Prime Line tend to be the lowest price for reasonable quality

 

[Dhunter0047]

I'm not seeing any part numbers on these guides, I have a la145 deere, would I be able to cross the flywheel from it with the engine I have and if there the same would I be able to look up the stator/regulator for it?

 

[bertsmobile1]

Any motor can have any stator &/or rectifier.
If you downloaded the afore mentioned guides they do have part numbers in the chart at the very back
The chart lists the engines by series MODEL numbers not actual number
Briggs code their alternators by the colour of the plug and the number of wires
For your application I would suggest the 592830 stator with the 845907 rectifier.
Run the single red wire directly to the starter solenoid battery feed , with a 20A fuse in the line , just in case you get short .
This rectifier draws a tiny current when the mower is turned off so you can pull the fuse to prevent the battery draining oner winter .
Go to Prime Line or Rotary & search for "Briggs Stator".
Don't buy off ebay or Amazon.
I regularly replace faulty cheap stators customers have fitted and have also rebuilt 2 burned down mowers cause the stators failed.
A couple of others the coils came loose & took all the magnets off the flywheel .

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[olie01]

Purchased a John deere gx345 which got a engine swap with I believe a 20 hp briggs intek engine and I have 2 major issues I need figured out.
1. Can not get it to charge a battery. Starting and driving around it does fine but as soon as pto is engaged it starts losing power. It has the red wire with diode and black wire from stator. It will only maintain around 12.8 to 13 running full throttle no load and drops to 12.4 when pto engaged.
2. It will not start on its own. I always have to pour gas in carburetor to get it to start then it'll run fine, and you can usually shut it off and restart after that for a bit before you have to gas it again.
Any help greatly appreciated!

Just did one on a L118, both motors are 23hp B&S, one is on john Deere and the other is on A craftsman. All I did wag swap the statter and flywheel, splice in the fuel line wire and the coil wire, unless you can get the pins out of the connector, and take the red wire, in my case off of the john deere motor , it runs under the statter shield on top of the motor.

 

[bertsmobile1]

HE does not have the old alternator. but you are right it is an easy job once the flywheel comes off.
I forgot to mention that the regulator rectifier usually mounts to the dip stick.
If you are buying from a mower repair workshop get the dip stick tube as well + the wires that connect between the alternator / rectifier to the mower.
Most small shops who repair rather than sell new mowers and just about every back yard workshop will have boxes full of this stuff cause we never throw anything useable out .