11HP Intek Engine Charging System Help Requested

Hello,

1st post. I am here seeking specific advice as I have just changed the engine on my 25 yo MTD riding lawn mower.

The old engine had low compression and the straw that broke the camel's back is the intake valve is sticking open. This engine is to old to rebuild.

Bought a new B&S 11HP Intek engine as a replacement (21R807 0072 G1). Horsepower and configuration are comparable.

The manual that comes with the engine give no information on the wiring and the B&S tech support person gave wrong information.

Regarding the charging system. There is a yellow wire coming from under the engine cover going to a regulator block and a red wire coming from this regulator block. I know that the red wire is my DC output for charging the battery and that the yellow wire is the AC output from the alternator that is rectified to DC.

With the old B&S engine the mower lights where connected to the alternator AC output but when I tried that with the new engine it blew the #1156 automotive lamps as quick as a fast acting fuse. Should I be using the AC output on the new Intek engine to run the headlamps? From that experience it seems not.

My current battery has a dead cell and is at 10.2 VDC with the engine off (New battery on order). With the new engine running the charging voltage is at 22.4 VDC. It seems as if this would "cook" my battery. Is this charging voltage high because of the dead battery cell? Did I damage the voltage rectifier/regulator when I hooked the headlamps up to the engine AC output?

I will add that to start the engine I am jumping it from my auto. With the jumper cables still attached to the mower battery and the Intek engine running the battery voltage is measuring a little under 13 VDC it when I remove the jumper cables from the mower battery that the voltage jumps to 22.4 VDC making me think that the increase may be the Intek engine trying to charge the battery with a dead cell and that with a new mower battery the charging voltage would be "normal". Your thought s please?

Vlad

The new charging system is not compatiable with your mower, end of story.
If you really want lights they will need to be wired into the DC side.

OR

you can pull the alternator ( flywheel & stator ) off the old engine & bolt it onto the new engine.
They all directly swap.

Thank you Bertsmobile1. I don't need lights. I won't be cutting the grass in the dark.

What about the +22.4 VDC? Is this because of the bad battery or a bad regulator?

Vlad

It is actually a little low so you must have the low output alternator
Not quite correct but basically V DC = 1/2 V AC
So a DC volt meter will read +12 V or - 12 V because it takes one lead to be = to 0V
The AC meter measures the difference from one lead to the other so will read 24 V ( hopefully ).
If you hook up the Ac meter and then increase the revs by moving the governor shaft with your finger it should rise to 26 to 30 Volts.
It needs to be a bit better than 24 Volts because the conversion to DC generates a bit if heat so you loose a few volts.

No idea why the globes blew.
But i am sure some one with better knowledge of mower wiring will be more than happy to explain.