Carb Failure/All HP Kohler Venturi Sizing

[oliver2-44 9,761]

I went to wake my C81 up from hibernation and no dice!  It would turn over, had spark and would run good as long as I sprayed gas into carb, fuel pump pumped gas with hose disconnected.  So time to pull carb and I found this.  The other piece was still held in place by the nut, but there was about a 1/8" gap between the two.  I imagine it was sucking too much air/gas through there to suck properly through the carb.  On the right side of the break you can see a slightly darker gray area that may have been a flaw or early part of the break.  The mounting nuts were not very tight so its hard to think I over tightened it this much.  This is a aftermarket  carb I put on it about two years ago as it came with no carb.  I bought two at the time, the one for my case 12hp constantly flooded/junk and this one worked so/so but didn't have a lot of adjustment effect when the needles were moved full range in and out.  

 

 

So this failure leads to questions so I can learn more about Proper venturi size!

As you may be aware the after market carbs are so where about 3 sizes fits all k series 4hp-16hp.

I Looked through my various good and spare/parts engines carbs and this is what I have

 

K91  4hp  venturi #18

K141 6hp venturi  #22  ??

K161 7hp venturi #20  ??

K181 8hp don't have

K241 10hp dont have at home

K301 12hp venturi #26

K321 14hp venturi #30 

K341 16hp venturi #30 

 

I did some googling and haven't found a Kohler chart listing hp/carb venturi size.

 

So what size is the proper venturi  (or what size venturi do you have on various K series engines.  I especially need the proper venturi size for the K181.  I'm thinikng of using the #22 off the parts K141 I have or buy a used one to rebuilt

No more aftermarket carbs for me!

 

 

 

Edited April 11, 2021 by oliver2-44

[953 nut 55,321]

Have you taken a look at this.

 

[squonk 41,155]

Good info here too! 

 

http://gardentractorpullingtips.com/a1carb.htm

[ebinmaine 67,627]

1 hour ago, oliver2-44 said:

No more aftermarket carbs for me!

 

Next time I need a carb I'll buy an oe used and rebuild it. 

 

[oldlineman 1,481]

I don't know why there seems to be so many carb problems. I have a 1979 c-101 ( bought new) with original carb never rebuilt only had to put new bushing on throttle shaft and a 1989 414-8 bought used about 20 years ago no carb troubles. Maybe I am just lucky but I do regular maintenance and use seafoam and corn free gas .  Now that I brought this up probable have all kind of problems. Bob

[squonk 41,155]

Things get older. Some are used more than others. They wear out They don't make them (USA) anymore. 

[ebinmaine 67,627]

1 hour ago, oldlineman said:

corn free gas

[oliver2-44 9,761]

Thanks everyone some good documents you've shared. 

 

4 hours ago, oldlineman said:

I don't know why there seems to be so many carb problems. I have a 1979 c-101 ( bought new) with original carb never rebuilt only had to put new bushing on throttle shaft and a 1989 414-8 bought used about 20 years ago no carb troubles. Maybe I am just lucky but I do regular maintenance and use seafoam and corn free gas .  Now that I brought this up probable have all kind of problems. Bob

 

The carbs on my 312-8 and C160 have worked excellent for several years after I cleaned/rebuilt them when I got them.  Each fall I run the gas off and run them dry. In the spring they start right up.  I use ethanol free gas 60%+ of the time and do my best to put them away for the winter with ethanol free in them.  

 

Interestingly the Walmart and Bucky's that I buy from near the farm both were out of ethanal free gas for all of March and I have not been by there in April.  There is a station/marina that sell it near me for double or more what I but it for near the farm.  They also had no ethanol.  

my C81 and Case 180 both came without carbs is why I tried the aftermarket route.  

Edited April 11, 2021 by oliver2-44

[roadapples 6,983]

I thought 14hp was supposed  to be a #28...

[ebinmaine 67,627]

3 hours ago, roadapples said:

I thought 14hp was supposed  to be a #28...

That's reasonable considering my 16 K341 is a #30. 

[squonk 41,155]

On 4/11/2021 at 5:18 PM, roadapples said:

I thought 14hp was supposed  to be a #28...

"This particular carburetor was designed specifically for the early Kohler engine model K321 with specification suffix "A", "B" or "C" (with the smaller 1-1/8" exhaust valve) and for certain early low RPM K341 engines."

 

From Garden pulling tips

[Handy Don 12,237]

3 hours ago, squonk said:

"This particular carburetor was designed specifically for the early Kohler engine model K321 with specification suffix "A", "B" or "C" (with the smaller 1-1/8" exhaust valve) and for certain early low RPM K341 engines."

 

From Garden pulling tips

Makes sense, then, that the carb can't mix in enough fuel to keep the proper ratio at the higher RPM. Running consistently lean can also cause other problems.