Gov/RPM set: am I doing something wrong?
 

After the recent motor swap on my Super, I wanted to make sure the motor was running top notch as it sounded too "tame" (didn't sound like it was running at the rpm it should be and seemed to be bogging down too low under high load when mowing tall grass). So I ordered a digital RPM gauge online and had a bit of time to play tonight. Starting off, the idle RPM was around 1000 rpm so I upped that to about 1300-1400rpm. All good there (based on the Kohler manual, of course). Then I set to work on the high idle. Butterfly wide open and I was getting about 1400 rpm or so at idle. So I, just to be safe, reset the gov as it should be (full counter-clockwise) and then adjusted the high idle screw. I tried half a turn, then a full turn, then two turns, and all I was able to achieve was upping it to about 3500+/- 50rpm. Seems like the adjustment should have had more effect than that as it hadn't changed much from when I started, no? Seemed like no adjustment I made changed it from the baseline of about 3450rpm very much. As time grew later, I had to quit as the neighbors had kids and I'm sure they wanted to sleep over the roar of the Super :biggrin2:

So, am I missing anything here guys? I had thought that no load the high rpm should be around 3600-3700rpm based on the Kohler service manual. Should I keep going or count my blessings and call it good? This rpm gauge, while it seems like it's working alright, it relatively untested. Thoughts on this? Opinions? Thanks guys :beerchug:

You're adjusting the high idle screw on the governor, right?
Is the cable pulling the governor lever all the way to the stop?
Is the dash throttle maxed out?
Did you readjust the governor?


Kohler wants all their engines idling too fast. I'd slow it down.... like a lot. 5-600 idle speed is really plenty. Just enough speed you can move it around without it dying. If it doesn't have a 60" deck, I would say just fast enough to be able to kick the deck on at idle without it dying.

I made this mistake last week on a CV490. I kept adjusting the screw and nothing was happening. Then I noticed that the arm was not hitting the screw and I adjusted the control cable.
Cannon

I am adjusting the high idle screw
The cable is pulling the governor lever to the stop
Dash throttle is maxed out
I did readjust the gov (that answer was at least in the op :biggrin2:)

Good tip, when I get her back in the shop (new garage door being installed today so shop is closed :() I'll slow her back down on idle a bit. :beerchug:

The twins sound good at low idle, almost like a Harley.

Years ago I had a customer who was undecided about which tractor to purchase...I had showed him a Simplicity landlord with a V-Twin Vanguard (better tractor) and a Toro Wheelhorse 260 series with the V-Twin Command. Soon as he heard the Command engine he bought the Toro Wheelhorse...because, he said it "Sounds Like My Harley!"

Lets try this again....


The screw on the governor?


Well, then keep turning the screw until it makes a difference. If it's out all the way and you still can't get more speed, your missing something obvious.


Dash throttle can't be maxed out if the cable is still pulling the governor arm to the stop. I meant, is the dash throttle maxed out, as in it can't pull the cable any farther because it's not adjusted right..... not are you running it all the way to the top. I want to know if you ran out of travel on the actual lever and it's limiting the speed.


Missed that.

What about spring position? Did you check to see that the spring was in the starting position holes?

Haven't forgotten about this thread/project John, just haven't made it to the Cub again to mess with it, hopefully this weekend. That being said...

The pic below I stole from online to use as a reference. The screw/bolt/adjustment pointed out is what I'm adjusting at this point. I had just been taking it easy as I didn't want to go from 3400rpm to 4000rpm as I wasn't sure of it's relative sensitivity.

https://s26.postimg.org/an28yl895/re...andchoke-1.jpg

As far as the dash throttle, it is not running out of travel and limiting things, this much I'm sure of. I've done dozens of other dash lever hookups/adjustments/etc and this hasn't been an issue before.

Lastly, the spring position: the pic below is an actual pic of my setup taken a week or so ago. I have tried the spring position in both hole 2 and 3. I'll explain that a bit. The pics below...below :biggrin2: are of the Kohler CH manual I've been referencing. It's not a Cub specific manual so it gives lots of options. The first pic is of the arm and it's possible hole configurations. The last pic is of the chart that tells what each hole's specific setting is based off of what kind of spring you have, etc. I'm sure I don't need to explain the pics as I have as I'm sure you've seem them a time or two more than I have :biggrin2: :beerchug: Just listing and posting them so you see what material I've been referencing.

https://s26.postimg.org/7hhn8dpmx/20170608_201225.jpg

https://s26.postimg.org/gdsfcbg95/20170608_193238.jpg

https://s26.postimg.org/xeet3vurt/Sc...8.21.37_PM.png

Well I got a little garage time in this morning and got things sorted out. I re-adjusted the throttle cable and gave the high rpm screw a few more turns. Set the digital tach to it and violla; just a few rpm above 3600 which is just fine with me. Also installed a longer oil filter since all I had when I did the swap was a (to me) stubby stock size oil filter. Took her for a spin around the yard and she purrs wonderfully! Now if the grass can just dry out a little more after all the rain we've had the last couple days, a grass killin I will go :beer2:

Next up, disassembly of the old engine but that's for another thread :beerchug:

glad you got it sorted out. :beerchug: