Author Topic: Anyone else running  (Read 4356 times)

0 Members and 1 Guest are viewing this topic.

Wheelhorseracer

  • Guest
Anyone else running
« on: July 03, 2008, 07:41:23 PM »
Anyone else running on Opposed Kohler Magnum?

I'm running one ungoverned and it is pretty quick.. but is a dog off the start compared to the vannies..

Anyone done any mods to theirs that they would like to share?

The only change to mine is headers and I swapped the emissions carb to an old style Kohler #26 carb with High Speed adjustment...

I'm running a centrifugal clutch with 3400rpm springs to a 90 box and a total final drive ratio of 7.50




Offline amcchevy1

  • Mow-Forum Junkie
  • ***
  • Posts: 1124
  • Karma: 2
  • Gender: Male
    • View Profile
Re: Anyone else running
« Reply #1 on: July 03, 2008, 09:47:41 PM »
i've got a kokler magnum 20hp on one of my mowers. it pulls good but just won't turn the rpms. it is stock with the exception of the governor, air cleaner and exhaust.
2007, 2008 amra member.  modified flathead
2008-2010 arma member.  sportsman
If you build it, it should fly.
take it out and let it eat...
www.GoLawnMowerRacing.com
www.alleghanymowerracingassociation.com

Offline Chris

  • Global Moderator
  • Turf Warrior
  • *****
  • Posts: 990
  • Karma: 25
  • Gender: Male
  • El Toro Asesino
    • View Profile
    • Off-Road Mowers!
Re: Anyone else running
« Reply #2 on: July 03, 2008, 10:05:38 PM »
I just picked up an opposed magnum - I haven't even had the chance to fire it up yet.
All-Terrain Lawn Mower Association Founder/Administrator


www.offroadmowers.com - When mowing the lawn just don't cut it!


Wheelhorseracer

  • Guest
Re: Anyone else running
« Reply #3 on: July 04, 2008, 06:53:25 AM »
The weird thing is that mine says Magnum 17 on the sticker but the numbers show that it is a magnum 18.. and the Toro dealer doesn't even have a list for a magnum 17.. just 16 and 18..

Mine seems to turn the rpm but out of the hole it is a bit doggy.. I don't want to gear it up sine i have no idea how the valve springs are..

I have thought about swapping the #26 for a #30 to help with air flow and see if that helps...


Offline outlawmower

  • Turf Warrior
  • **
  • Posts: 538
  • Karma: 3
  • Gender: Male
    • View Profile
Re: Anyone else running
« Reply #4 on: July 04, 2008, 07:48:08 AM »
Wheelhorseracer,

Here are a couple things I have learned that ALL kohler engines love.... AIR FLOW!
On my 10hp Kohler engine I built to the hilt I made 55HP @ 52#'s Of torque. Thats with a #30 carb bored out by Brian Miller. Also you need to let the ports FLOW! Kohlers are nothing but air hogs....

2.- Now on kohlers the rod beams have a rough casting and that increases STRESS! You dont want this. By cutting that down smooth and polshing the rod it will help reduce stress and keep some weight off because the oil will not stick to the rod as much.

3.- Another little trick I do is if you have acces to a mill is in the wrist pin side of the rod drill 2 oil holes.

4.- Off-set grinding the crank. ONly go about .010 and then shave the pistons for zero deck. It will increase tourqe. Dont have to do this but some do... All depends on you class rules.

5.- Just true up the heads. Thats all that needs to be done here....

O and for your #26 or #30 carb IMO that this little peice from Midwest Super Cub will help the carb breathe a little better also-



New & Improved: Accepts K&N air filter. Polished Billet Aluminum Velocity Stack.  Bolts onto Kohler carb using the three screw holes that hold the air cleaner on (screws supplied with velocity stack).  The stacks have been flow tested to give you maximum flow, yet still being able to bolt them right on.  $52.50



K&N High Performance Air Filter. Clamp on 7" dia x 6" long.  Fits MSC Velocity Stack and Vogel Velocity Stack. $54.00

www.midwestsupercub.net

Outlaw
PUT YOUR GAME FACE ON!!!

Offline 300xdeere

  • Turf Warrior
  • **
  • Posts: 764
  • Karma: 3
    • View Profile
Re: Anyone else running
« Reply #5 on: July 04, 2008, 09:53:05 AM »
Also, i know for a fact that the motor will turn rpm, and take it like a champ. When i had that motor on my mower it would hit 6200-6400rpm. I personaly thing, Jason you still have to much gear. Because the torque on that kholer beats the torque of a vanny hands down. But only because the vanny's you race with are stock. That and your motor doesn't seem to run very well. I don't know if its the way the carb is set or what but that thing beraly idles and seems to spit and sputter alot, not sure what it is though never really thought about it until you posted this. Just my opinion cya tomorow.

Wheelhorseracer

  • Guest
Re: Anyone else running
« Reply #6 on: July 04, 2008, 01:17:20 PM »
I think the sputter you hear is the exhaust leak I have between the header and the head.. it idles quite well... even better than my BUILT 8 hp Kohler.. How many races again did you win with this engine 300xdeere?

Thanks for the heads up outlawmower.. I thought about a velocity stack and carb spacer to help the flow...

I might even go twin 26's carbs cause it is legal in my class..... that would look neat.. :D

The wonders of running a flatty when the OHV's aren't allowed any mods.. but the flatty is open book... :D



Offline amcchevy1

  • Mow-Forum Junkie
  • ***
  • Posts: 1124
  • Karma: 2
  • Gender: Male
    • View Profile
Re: Anyone else running
« Reply #7 on: July 04, 2008, 01:23:19 PM »
i know they make a 17. i bought a carb for 1 @$175.00 ( customer cost. i paid $153.) it was an mv17s.
2007, 2008 amra member.  modified flathead
2008-2010 arma member.  sportsman
If you build it, it should fly.
take it out and let it eat...
www.GoLawnMowerRacing.com
www.alleghanymowerracingassociation.com

Wheelhorseracer

  • Guest
Re: Anyone else running
« Reply #8 on: July 04, 2008, 01:25:51 PM »
Really?... that's good to know... I couldn't find anything on them..

Offline FlatheadPuller

  • Turf Warrior
  • **
  • Posts: 967
  • Karma: 12
  • Gender: Male
    • View Profile
Re: Anyone else running
« Reply #9 on: July 04, 2008, 01:44:13 PM »
Outlawmower,

Do you have a dyno sheet to prove that 55hp 10hp kohler?



Dennis Bazzett
Grandville Michigan

Offline 300xdeere

  • Turf Warrior
  • **
  • Posts: 764
  • Karma: 3
    • View Profile
Re: Anyone else running
« Reply #10 on: July 05, 2008, 07:56:20 AM »
My best finish on that motor was 3rd in harrow, never had an issue with the motor lots with the mower. Unfortunately I only did maybe 6 races last year so the first 4 of those races i was getting the bugs out of a new tractor. Towards the end of the races i was doing pretty good. Cya today at the race Jason  8)

Offline John692

  • Turf Warrior
  • **
  • Posts: 297
  • Karma: 3
  • Gender: Male
    • View Profile
Re: Anyone else running
« Reply #11 on: July 05, 2008, 12:05:12 PM »

On my 10hp Kohler engine I built to the hilt I made 55HP @ 52#'s Of torque.

hmmmmm. Interesting.
John #692
USLMRA
PALMRA
IMOW
C/P in the works

Offline Dylan

  • Turf Warrior
  • **
  • Posts: 274
  • Karma: 1
    • View Profile
Re: Anyone else running
« Reply #12 on: July 05, 2008, 10:05:20 PM »
hes at 7.50 gear now.. im tryin to get him to go to 7.00 and get some one to time his laps.. and then go to an 8.00 and again.. and if the 7 is faster.. slowly go down to se how fast he can get it...
Dylan
03 Modified

www.westernontariooutlaws.com

Wheelhorseracer

  • Guest
Re: Anyone else running
« Reply #13 on: July 06, 2008, 07:40:04 AM »
I might try the 7.00 next weekend at Stonehouse... if my back is up to going under the mowchine...