Kohler carburetor pictorial

[ebinmaine 68,406]

I had a Kohler #30 carb for my own C160-8 Cinnamon Horse on the bench today. 

This one's been soaking in the lacquer thinner for several weeks along with quite a few sessions in the ultrasonic cleaner.  

Here's a couple "before" pics. 

 

 

 

 

I use a combination of the above soak & ultrasonic cleaner intermixed with wire brushing by hand and machine. 

VERY.... CAREFUL.... USAGE....  of the machine spun brush. 

 

I also use a small pick and/or screwdriver and/or whatever's to hand for cleaning the grit and muck from orifices and corners.  

 

After the greatest part of the grime is gone I use a series of drills in the Dremel tool to bore a 1/8" hole in the welch plug on the side. Pop that out with whatever levering tool is close and works.  

 

More cleaning. More scraping. More brushing. Repeat. Repeat.  Intermix as needed.  

Be sure to get in the area behind the welch plug and clean carefully. Also clean the tiny holes the feed fuel to the main bore. I use a tiny drill bit. Carefully.  

 

All the small pieces also need de-grubbing and anti tarnish treatment.   

 

I use a 3-48 tap to clean the threads of all 4 holes from the throttle and choke shafts.  

 

 

 

Once the body is clean..  I start reassembly.  

 

Here's the complete exploded parts assortment sans the 3/8" welch plug I forgot to set there. 

 

 

 

Welch plug hole shown empty. 

 

Plug setting in but not driven/flattened. 

 

 

Post flatten. I use the bit that's on the carb to indent the plug. Anything roundish and 1/4" or so diameter can be used. The larger bar in my hand is the "hammer/ hammah".

 

 

 

Procedure for driving in the upper throttle shaft bore repair washer is similar. 

One of two in place. 

 

 

Both set in. 

 

 

Here's a closeup. You can see the two washers stacked and stuffed. 

 

 

 

Now I move to installing the throttle and choke shafts and blades. 

I use Blue Loctite. Brand name only.

Four new screws. These are usually 3-48.  

Just the tiniest little dab of Loctite on each screw. 

Get the screws in place loosely then verify proper movement and placement of the blades. Each blade will usually need a little coaxing to set just right.  

Once that's satisfactory, tighten the screws. 

 

 

 

 

Now I install the 3 exterior screws. 

1.  Idle speed control. Small silver colored one. I always start high and adjust the RPM down later.  

2. Upper RPM mixture. Coincidentally that's also the uppermost positioned screw.  

3. Low RPM or idle air mixture screw. 

 

 

Be sure to set the above screws to the factory settings before starting the engine. 

 

 

 

The fuel inlet seat is threaded in next. I have a special nut driver I've modified by grinding down the circumference so it fits in the limited space. 

 

Drop the needle in and slide the float pin through. Check the adjustment. I set floats for these carbs about parallel with the body. 

 

Install the bowl gasket, then the fuel baffle. Center the bowl. Install the gasket and bowl retaining nut. Snug that up well but use caution to not overtighten particularly on original aluminum bowls. I most often replace the bowl with a Briggs and Stratton steel bowl. The older aluminum bowls are almost always crushed and deformed around the bolt hole.  

 

 

 

 

A few more pictures as completed.  

 

 

 

 

 

 

 

[OutdoorEnvy 1,578]

Very nice process and great tutorial EB!  This will help a lot of folks 

[c100rider 141]

Definitely helps me. Carb rebuilds is witchcraft to me. 

[ebinmaine 68,406]

Just now, c100rider said:

Definitely helps me. Carb rebuilds is witchcraft to me. 

 

Understandable.  Patience is key.  

 

 

 

4 minutes ago, OutdoorEnvy said:

Very nice process and great tutorial EB!  This will help a lot of folks 

Thanks....

I'm hoping....

[squonk 41,349]

Bowl nut always leaks. Old bowl , new bowl, new nut doesn't matter. I started using Permatex Aviation sealer on the new nut gasket. The new gaskets are plastic. The old ones are metal. The last carb I did I re used the metal gasket. It's for stock so I still don't know if it's going to leak or not.

[ebinmaine 68,406]

33 minutes ago, squonk said:

Bowl nut always leaks. Old bowl , new bowl, new nut doesn't matter. I started using Permatex Aviation sealer on the new nut gasket. The new gaskets are plastic. The old ones are metal. The last carb I did I re used the metal gasket. It's for stock so I still don't know if it's going to leak or not.

 

 

Keep us posted on the leakage when ya install that.  

[WHX?? 49,175]

1 hour ago, ebinmaine said:

Patience

What's that?? 

I have never taken out the welsh plug. Figured if you was supposed to there would be one in the kit. 

Now you know why I sent you a box of carbs to play with ... 

[c100rider 141]

1 hour ago, ebinmaine said:

 

Understandable.  Patience is key.  

 

 

 

Thanks....

I'm hoping....

I've done rebuilds before. Not too bad. My main problem is the screw mixtures. I don't have an ear for the tuning.

[tunahead72 2,433]

That's exceptional work, Eric, nicely done!

 

[Bar Nuthin 541]

I swapped out my original carb for a Wuhan. At the time I decided a $20 carb would give time find a replacement needle. The PO must have torqued it down too hard and buggered the tip. The only needles I saw at the time were like $75.

I figured at some point I will refurbish it. But now I'm thinking I'd be better off mailing it to Eric! 

Edited Sunday at 03:00 AM by Bar Nuthin

[kpinnc 12,539]

5 hours ago, ebinmaine said:

Thanks....

I'm hoping....

Absolutely beautiful! Makes me wanna ship you all of mine in the future! 
 

Only one thing I would add- I prefer brass screws on the butterflies. I had one come loose from the choke plate about a month after a rebuild. Made the most horrible sound you’ve ever heard in a Kohler. When I pulled the head, the screw was mashed flat. Had it been steel, I’m sure the piston and head would have been ruined. 

Edited Sunday at 06:10 AM by kpinnc

[ebinmaine 68,406]

5 hours ago, kpinnc said:

Absolutely beautiful! Makes me wanna ship you all of mine in the future! 
 

Only one thing I would add- I prefer brass screws on the butterflies. I had one come loose from the choke plate about a month after a rebuild. Made the most horrible sound you’ve ever heard in a Kohler. When I pulled the head, the screw was mashed flat. Had it been steel, I’m sure the piston and head would have been ruined. 

 

I understand your logic and quite frankly, using the steel screws bugs me for that very reason. 

 

I switched to steel a few years ago for several reasons. 

Brass screws were not readily available to me here. 

Steel is a LOT easier for me to tighten properly. 

I've read that Loctite bonds with steel better. (That may be hogwash)

 

Most importantly and most concerning to me. .... I've broken some brass screws while assembling. 

[ebinmaine 68,406]

9 hours ago, WHX?? said:

What's that?? 

I have never taken out the welsh plug. Figured if you was supposed to there would be one in the kit. 

 

 

Your logic is sound there.....mostly. 

The "kit" Kohler makes also doesn't include the gaskets for either end even though you should ALWAYS replace them. 

 

I started removing the plug on EVERY carb fairly recently myself. 

I'm glad I've done this because there's usually a bit of shmootz in that little cup.  

[ebinmaine 68,406]

8 hours ago, Bar Nuthin said:

 The only needles I saw at the time were like $75.

I can check to see if I have any extra needles. The long main one?

 

 

8 hours ago, Bar Nuthin said:

I figured at some point I will refurbish it. But now I'm thinking I'd be better off mailing it to Eric! 

 

Ship it up. 

[953 nut 55,827]

12 hours ago, ebinmaine said:

Also clean the tiny holes the feed fuel to the main bore. I use a tiny drill bit. Carefully. 

I have been using torch tip cleaners for this, works well.          

[squonk 41,349]

So Eric, where are you getting the plugs from? I got a junk carb here I may yank the plug out and see how much shoogatzi is in there.

[ebinmaine 68,406]

17 minutes ago, squonk said:

So Eric, where are you getting the plugs from?

 

I'll post a Pic later. It's a place called Mike's.... something... out in CA.  

 

17 minutes ago, squonk said:

 shoogatzi

 

A technical term?

[Bar Nuthin 541]

1 hour ago, ebinmaine said:

The long main one?

 Yes, sir!

[leabassett@sbcglobal.net 151]

Looks like new. Great job.

[Oldskool 6,653]

Looks brand new. Great tutorial.

I really should follow your process to rebuild one or two or ALL my carbs.

Thanks for posting this.

[fourwheelhorseman 320]

Man Eric, you’ve got this down to a science! Ive cleaned a lot of carbs in my day, but never to this level. The carb I got from Eric looks simply brand new and works like it is. Btw,  and maybe you’ve already revealed this before and I missed it, but what kind and size sonic cleaner do you have? 

Edited Sunday at 02:33 PM by fourwheelhorseman

[ebinmaine 68,406]

1 hour ago, fourwheelhorseman said:

what kind and size sonic cleaner do you have? 

 

Inexpensive one from Vevor. 

 

Mine is a 3 Liter model with good old fashioned round manual knobs to set heat or time.

No digital anything. 

I don't use the heater because I still use the lacquer thinner. I may switch to a less volatile fluid like pine sol. 🤔 

I've stayed with lacquer thinner because I REALLY like the way it works to shine up the aluminum after some light wire brushing. And more importantly,  it doesn't have any negative effects on the main SEAT I always leave in the body.  

 

 

Edited Sunday at 03:39 PM by ebinmaine
Fixing Bear silliness

[tunahead72 2,433]

6 minutes ago, ebinmaine said:

 

... I may switch to a less volatile fluid like pine sol. 🤔 ...

 

I've stayed with lacquer thinner because ... it doesn't have any negative effects on the main needle I always leave in the body.  

 

 

I'll be interested in hearing your thoughts on pine sol as a carb cleaner when you get to it.  I used to follow a motorcycle forum that included a group of guys who used it regularly and swore by it.  And just now I did a quick search and realized there's a group on this forum as well.

 

Also, are you talking about the long mixture adjustment needle, and if so why do you leave it in the body for cleaning (your photos show it removed)? 

 

[midpack 892]

17 minutes ago, ebinmaine said:

 switch to a less volatile fluid like pine sol. 🤔 

 

 

I've used Simple Green in mine. There's an aircraft version but I haven't used it on carbs

[ebinmaine 68,406]

10 minutes ago, tunahead72 said:

 

I'll be interested in hearing your thoughts on pine sol as a carb cleaner when you get to it.  I used to follow a motorcycle forum that included a group of guys who used it regularly and swore by it.  And just now I did a quick search and realized there's a group on this forum as well.

 

Also, are you talking about the long mixture adjustment needle, and if so why do you leave it in the body for cleaning (your photos show it removed)? 

 

 

I messed up that sentence.  

I meant main SEAT.  

 

I'll go fix it.