Problem with Carb Kits, o ring gaskets

[Skwerl58 704]

I have rebuilt three carbs this year and each with different kits. One from the ROP shop, 2 Stens and 1 Kohler. The issue I am having is with  the o ring bowl gaskets. I just used the Kohler bowl o ring gasket yesterday and today I tore the carb down and the gasket is soft and swollen so it can't be reused. I use non-ethanol 93 octane gas in my power equipment. I have talked to my local Toro dealer and Kohler has no idea what it is. I have three kits minus the o-ring gasket so what now?  I actually took the one out of my old 414-8 carb and used it in one of my rebuilt carbs, it is still good after 36 years. Crazy but does anyone have any suggestions?

[rmaynard 15,481]

O-ring? Never heard of one. All the rebuild kits I have ever used have a square-cut bowl gadget and splash shield.

[Skwerl58 704]

Yeah, it is the flat round gasket

[ebinmaine 67,525]

Those gaskets can be purchased separately.  

 

I've had them dried up and gone crispy but not smooshy or swollen.  

 

I've had carbs I need to clean two or three times to get all the nitty gritty out. That gasket is usually reusable but I may have some spares here.  

 

 

[WHGuy413 2,689]

What are you using to clean the carb? I have had carb clean and brake clean swell the o rings to the point they don’t fit. I leave them out in the sun after this to get them to go back down to size.

[wallfish 17,000]

Always referred to them as square cut O rings but still O rings none the less

Don't spray them with carb or brake cleaner. remove them first. They will swell but will shrink back but it seems they deteriorate quicker

 

[Skwerl58 704]

I learned the hard way about carb cleaner and some rubber or soft gasket material. The splash gasket curls and the flat o ring gasket swells. I didn't get any on the gasket yesterday which flustered me when it was not usable today. I have ordered a kit and also 6 factory nos flat o ring gaskets so hopefully that will keep me for a while.

[rmaynard 15,481]

I have rebuilt many carburetors over the years, but found lately that rubber bowl gaskets removed from carburetors that were rebuilt within the last 5 years all tend to swell and get larger in diameter. However, I have also found that if I don't get back to a rebuilt, and let the gasket sit for over a week, it returns to it's original diameter. 

[RED-Z06 2,221]

Its been a problem for a while, when tecumsehs were still a thing we had to deal with, it was just understood that if the bowl gasket touched fuel...it was going to swell, i used to wash them and put them in ice water..usually they would retract when dried out.  Its the fuel..its not necessarily ethanol, its just the fuel.