Need More Electrical Power

[SkidRoe]

The stock alternator in the repower is barely cutting it.
The original Kohler had about a 20 amp charging circuit, and the 20hp Launtop only has 3 amps on tap (engines with 20 amp alternators were available, but I got this engine cheap). It is barely passable to recharge the battery after starting, and running the fuel pump / fuel shut-off solenoid (so long as you are not starting and shutting down a lot), but lights are out of the question.
I priced the Honda parts to put their 20 amp alternator coils / regulator in, and it comes out to about $400, plus you have to pull the motor to do it (fly wheel has to come off).
So my plan is to belt drive a second alternator from the crank shaft. I picked up a new 55 amp Denso one-wire for about $85, and will be installing a 4" pulley on the crank to drive it. These alternators are becoming really popular with hot-rodders, as they are really compact.
The parts are coming together and I am hoping to get a start on it over the weekend. And I will be taking pictures.
More to come,
SR

 

[SkidRoe]

I did the install today, it fit better than expected.

I mounted it off of two of the bolts that secure the pump plate to the engine. There was just enough room behind the main drive pulley to slot in a second pulley (4" OD) to drive the alternator. Basically, it was just 3 parts to fabricate: the lower mount made from a piece of 1.5" heavy wall square tubing, a stand off for the adjuster link, and the adjuster link itself.
The alternator charges 14.5 volts at idle with all of the lights on. Much better.
I actually ended up disconnecting the original alternator and removing the rectifier / regulator.

 

[Mikefromcny]

I did the install today, it fit better than expected.


I mounted it off of two of the bolts that secure the pump plate to the engine. There was just enough room behind the main drive pulley to slot in a second pulley (4" OD) to drive the alternator. Basically, it was just 3 parts to fabricate: the lower mount made from a piece of 1.5" heavy wall square tubing, a stand off for the adjuster link, and the adjuster link itself.
The alternator charges 14.5 volts at idle with all of the lights on. Much better.
I actually ended up disconnecting the original alternator and removing the rectifier / regulator.

Looks good, Lights and charging systems are usually the first thing I fix on a machine, nothing bothers me more.

 

[SkidRoe]

Looks good, Lights and charging systems are usually the first thing I fix on a machine, nothing bothers me more.

I hear you. With these one wire alternators, there is no excuse for not having a decent charging system on older equipment.

 

[stingraygs]

I did an almost identical Denso alternator mod on a Bobcat 722 I re-powered with a 35 HP Briggs Vanguard. I run twin electric fans, one on the hydraulic cooler and one on the Engine, for when I sit stationary and use heavy hydraulic load like stump grinding or trenching. I has worked great for several years now. Hope yours works as well.

 

[SkidRoe]

I did an almost identical Denso alternator mod on a Bobcat 722 I re-powered with a 35 HP Briggs Vanguard. I run twin electric fans, one on the hydraulic cooler and one on the Engine, for when I sit stationary and use heavy hydraulic load like stump grinding or trenching. I has worked great for several years now. Hope yours works as well.

Yup, so far, so good. Nice having plenty of electrical power on tap. Cheers!

 

[mmsllc]

Yup, so far, so good. Nice having plenty of electrical power on tap. Cheers!

Looking really good. Really cool to see this done as an easy alternative. Nice job.

 

[SkidRoe]

Looking really good. Really cool to see this done as an easy alternative. Nice job.

Thanks! Still going strong. I have yet to have any issues with it. Cheers - SR