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Author Topic: Kohler Single 490cc Mild Build Help  (Read 1424 times)
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tractorbuds
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« on: November 14, 2013, 05:01:12 AM »

Here's what I have. CV492S

MWSC: new style aluminum flywheel, springs, retainers, racing hyd lifters, copper gasket.

Going to run stock internals, fresh rings, valve job, clean up the head a bit, for a season and go from there.

I am wondering if I am better of running a small block head to increase compression or just shaving the existing head? If shaved, how much? If I do go with a long rod and piston combo next year, I don't want to find myself in a situation where the head has been shaved too much to handle the new displacement.

Also, I've been told not to exceed 6000 rpm on stock internals, what compression number should I be aiming for?

Finally, am I going to get away with running the stock carb, reworking fuelling, or am I better of switching to something else? Gotta stay on a budget though.

Thanks for your help. Just trying something different than B&S for the heck of it!

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Burton for Certain
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« Reply #1 on: November 14, 2013, 09:26:11 AM »

Hydraulic lifters will keep it from going over 6,000. Weakest link is the cam if ya doing anything crazy with it. small block head is fine.  Find a carb off an old k series kohler single.
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« Reply #2 on: November 14, 2013, 10:01:40 AM »

The stock balancer is also a weak point. Don't go any higher than 6k rpm with that in there, or it will be a time bomb for sure. Put the right parts in one of these and it will be a front runner.
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Tyler Cromwell - Cromwell Racing Engines, specializing in Briggs and Stratton Vanguard and Kohler Command V-twin engines, from mild to wild! Built to win, built to last.

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« Reply #2 on: November 14, 2013, 10:01:40 AM »

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tractorbuds
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« Reply #3 on: November 14, 2013, 04:26:14 PM »

So use a small block head instead of shaving? Or, is one going to be way better than the other?

Also, on the K series carb, I assume I'm looking for one to gain fuel mixture adjustment? Is it a direct blt on?

Sorry for al the questions and thanks very much for your advice.

Rods, JR
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Mowerstompin
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« Reply #4 on: November 15, 2013, 05:55:14 AM »

The carb you want is a kohler carter #30 off the kohler k series motors.
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Cody Whisenhunt #83
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« Reply #5 on: November 15, 2013, 09:25:58 AM »

I would just use the head you have. Clean up the ports and do a really good valve job. And yes the #30 carb is the one to use. They can be hard to find but i was able to get a few new ones. Cool A Tillotson HR would be best but not sure if your rules allow that or what class you are building it for.
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Tyler Cromwell - Cromwell Racing Engines, specializing in Briggs and Stratton Vanguard and Kohler Command V-twin engines, from mild to wild! Built to win, built to last.

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« Reply #6 on: November 15, 2013, 12:37:03 PM »

What are you guys doing to remove the balance shaft?
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tractorbuds
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« Reply #7 on: November 15, 2013, 03:51:37 PM »

I wasn't planning to do anything to the bottom end at all, just running stock internals with fresh rings. I realize I am going to have to watch how high I rev it, and I'll play it safe. We run the Honda too, really nice torque, so we don't have to get too concerned about making them scream.
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tractorbuds
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« Reply #8 on: November 17, 2013, 06:11:23 AM »

Hey guys, what are your feelings about the aftermarket #30 carbs on ebay? Anyone tried these.....I have had my fair share of grief with old carbs, sinking time and money into them and unfortunately have nothing on the shelf to start with so I'm in a situation where I have to spend money. For my application, an $80 aftermarket carb is looking pretty intriguing. Your advice appreciated.
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Jeff McKelroy #55A
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« Reply #9 on: November 17, 2013, 08:02:45 PM »

Hey guys, what are your feelings about the aftermarket #30 carbs on ebay? Anyone tried these.....I have had my fair share of grief with old carbs, sinking time and money into them and unfortunately have nothing on the shelf to start with so I'm in a situation where I have to spend money. For my application, an $80 aftermarket carb is looking pretty intriguing. Your advice appreciated.

No midrange for roundy-round.  for pulling, they work great.  I have two new ones, sans choke if you're still interested in one.
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tractorbuds
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« Reply #10 on: November 17, 2013, 08:15:52 PM »

I am running this old Walbro LUA carb from an Onan on my 35 ci Vanguard, a direct bolt on for horz application, simple mixture adjustment and I am half tempted to fab an intake a just try it on the Kohler.
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« Reply #11 on: November 17, 2013, 09:06:14 PM »

The OEM kohler #30 carbs work great for pulling and racing. That's what I would use if rules wouldn't allow a Tillotson.
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Tyler Cromwell - Cromwell Racing Engines, specializing in Briggs and Stratton Vanguard and Kohler Command V-twin engines, from mild to wild! Built to win, built to last.

Love God, Love Others - 4GIV
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« Reply #12 on: November 18, 2013, 12:53:56 AM »

OK. I'll get on the hunt for one.
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tractorbuds
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« Reply #13 on: November 24, 2013, 07:44:49 PM »

Hey guys, I suppose I can call MWSC, but what should I be torque ing the head to when using a copper gasket?
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Burwell555
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« Reply #14 on: November 25, 2013, 11:56:15 AM »

Copper headgasket and fire ring from MWSC, 30 foot pounds
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Zach Burwell
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