View Full Version : Kaw FD750D Overcharging??

10-08-2009, 10:21 AM
Hello! I bought a used 2005 Scag TT this spring. The old owner just replaced the battery. I ran most of summer, then it wouldnt start. Battery was DRY - needed tons of water. I replaced battery with another new one and it started right up!

BUT, I then checked the voltage across the battery - its 17.5V

Is my voltage regulator definitly the problem here?? I hate to spend $200 and find out I missed the problem!

Thanks so much!!

10-08-2009, 01:32 PM
Where in the world are you going to pay 200 bux for a regulator ?


10-08-2009, 02:10 PM
Thats the price I have found online at 2 different places. I have not called dealer yet.

Its a FD750D

10-08-2009, 02:45 PM
OK, dealer wants $133 - thats a lot better!!

But he mentioned checking stator first - at 28V

I am not electrical genius, but not toooo stupid either.....lol. Could somebody help me with how to check stator voltage?? then reg voltage??

Thanks VERY much.

p.s. - I DO plan on buying the Kaw service manual, but I dont have one as of now.

Ruben Rocha
10-08-2009, 06:11 PM
I believe if you search for stator here you will find some posts by restorob.
But it should be like 28volts ac usually I think before the regulator.
to test remove the connector from the regulator and measure the voltage from the stator.
Of course the engine running full rpm
The regulator changes the voltage from ac to dc.

10-08-2009, 08:47 PM
As Ruben mentioned the stator puts out AC voltage so make sure your meter is set on AC when performing the unregulated test, You will most likely find the stator good since it is over-charging.

Did you click on the link I posted in my first reply ??? Regulator 68 bux......

Test as below;


Regulator out-put voltage is checked at the battery like you have already done.

10-09-2009, 12:59 PM
Great info - and I do apprectaite it! I will test it tomorrow and let you guys know what I found out (for others reference too). And I did miss the link you added resto... Thanks!! Awesome price!

10-10-2009, 02:19 PM
Hi all. I checked as shown. I think all is ok, but let me ask this. When I run the mower at 1/2 throttle, I get 28.6V ac, but when I run it at full throttle I get 36ishV ac. I dont have a way to see when I am running at 3000rpm.

Is the 36V at full throttle too high and burning up the regulator? Or are these the numbers I should expect??

Then, jumping across the battery it read 15.5v dc half throttle and 17.5v dc full throttle.

If sounds ok, I will order the voltage regulator!!

Thanks so much!

East Coast Lawn Choppers
10-10-2009, 05:20 PM
I've had most around 33VAC at full throttle, seen some up around 35 or so, the regulator is just what it says a regulator. The 26VAC is a minimum. I never seen a max posted anywhere. I know on the kohlers the test is any thing over 28VAC the stator is good. The regulator does two thing mainly... it has a bridge in it to convert ac to dc, then it has a regulator in it that should regulate the voltage to approx. 13.8-14.7 depending on the regulator.

10-10-2009, 07:00 PM
I never seen a max posted anywhere.


It's the minimum voltage that denotes if you have a faulty stator.

10-10-2009, 10:44 PM
OK, sounds great!! An easy fix too!! Thanks everybody!!
One last question if you dont mind.....before I hit the "buy" button......

The regulator on the web site you sent me the link to, is it a good quality part??

I like to spend a few extra $$ to get good parts!! But if you guys have had luck with this regulator and it is a known quality part, half price sounds good to me!

I noticed the Kawasaki reg may actually be MTD - and its $140-$150. Big price difference.


10-10-2009, 11:08 PM
A electrical part is just like a tire, It can go flat at any given second.....

Buy any one you want but MTD has nothing to do with building the regulator.

10-18-2009, 10:12 PM
OK! I finally got my regulator and installed it. I cleaned out my connector with NAPA electronid cleaner, then added som edielectric grease to the connector and installed the new regulator.

Now when I start it I get about 15.3V DC across the battery at a higher rpm and 14.8 or 14.9 at lower rpm. I did see it hit 15.5 once for a bit. The after I mowed 2-3 hrs, but the last hour running lights - it still read 15.3.

Is it still too high??

Thanks all!

10-18-2009, 11:03 PM
What's the voltage in the battery now just sitting there, Then remove the plug wires and crank it over watching the meter. Post both just sitting and voltage drop while cranking readings.

10-19-2009, 08:25 PM
OK, just sitting there - the battery reads 12.83 While cranking, plug wires off, it dropped to 10.82. After cranking, just sitting there, it went back to 12.58. I cranked it maybe 10 sec max. I use a Fluke meter - should be accurate. Also, I forgot to mention earlier I also replaced the battery. Its a brand new Interstate Workaholic 300CCA.

Thanks again so much!!

10-19-2009, 09:22 PM
I'd just run it a few days then check it again, 15.3 is just a little high but your battery at 12.83 is a little high as well.....

10-20-2009, 08:57 AM
Sounds good - I will do that!! I probably only have 1 more cut this year anyway. But I did want to get her all worked out now so I didnt have to deal with it inthe spring. I assume the regulator ground is thru a wire and not thru the case bolting to the mower brackets - because everything is painted. So I didnt take a lot of time to clean between regulator and mower.

Like you said, I run er and check after my last mow, and I will make sur I dont run lights.

On another subject all together, not a question, just a thought.....if I am going to run this mower forever which I plan on, I may switch my light kit to LED lights and while I am at it, mount them higher on the roll bar. Better visibility, and way less draw on the system.

Thanks everybody (especially restrorob) very much for helping me thru this!!!