Do Carburetors wear out?

[Beltrack]

I’ve seen lots of discussions recently about replacing stock carbs with Asian “will fit” carbs. What is it that wears such that it can not be repaired/overhauled? Everything is available isn’t it? Needle, seat, floats, throttle shaft bushings etc? Help me understand.

 

[1811Cub]

Throttle shaft bores do wear out, but they can be bushed. Really the only killers to carb bodies are thread damage, heavy corrosion, or cracks. Also be aware that some of the mixture needles get ruined due to overzealous tightening. If you address the throttle shaft wear, ensure needle quality, chemically clean the carb body and blow out all passages, and use OEM carb kits and floats, it most likely will run well.

 

[Beltrack]

Thanks

 

[1811Cub]

Most if not all the interest in the Chyna replacement carbs is centered around only one thing-cost. Most of them are cheaper than a proper rebuild kit from Kohler. Also, they do look good with all of the freshly plated parts. The problem with them lies around inconsistent machining quality and the metal used to cast them. They are a lower grade than OEM, so presumably they won't last as long. I have used a couple of them with good success, but have only bought them to replace a fixed main jet Walbro. Walbros aren't worth a rebuild kit and the time to rebuild them. I make an effort to rebuild the OEM Kohler/Carter style fully adjustable carbs.

 

[Greg Riutzel]

Don't forget linkages. Single cylinder engine vibration is hard on them and after many hours get elongated and sloppy. Loose throttle shafts can allow the butterfly to chafe the bore to were idle adjustments are time wasters.

 

[spndncash]

Thanks

as stated above price, but also the issue is the parts or even complete kits are not stocked as often as some of the asian full replacement carbs are. I have a yamaha G2 gas golf cart that needed a carb rebuild and after waiting on the parts for two weeks I bought a ama%$* chinese carb for less than half the price of my rebuild parts. the chinese carb came overnight and my wife was back to gardening that day with it. almost two weeks later i got the parts, rebuilt the original carb and it now sits on the shelf waiting for china to let me down.

 

[mgonitzke]

as stated above price, but also the issue is the parts or even complete kits are not stocked as often as some of the asian full replacement carbs are. I have a yamaha G2 gas golf cart that needed a carb rebuild and after waiting on the parts for two weeks I bought a ama%$* chinese carb for less than half the price of my rebuild parts. the chinese carb came overnight and my wife was back to gardening that day with it. almost two weeks later i got the parts, rebuilt the original carb and it now sits on the shelf waiting for china to let me down.

At least currently this is not an issue for K-series engines. The OEM carb kit for them is easier to find than aftermarket kits or even whole carbs for some of the newer engines.

Don't forget linkages. Single cylinder engine vibration is hard on them and after many hours get elongated and sloppy. Loose throttle shafts can allow the butterfly to chafe the bore to were idle adjustments are time wasters.

This is fairly easily remedied with some off-the-shelf bronze bushings (at least for the K241-K341 and KT-17 adjustable carbs).

I have this pile of worn OEM carbs I need to get fixed up and sold one of these days. All will need rebuild kits, throttle shaft bushings, and maybe a helicoil here and there.

 

[spndncash]

At least currently this is not an issue for K-series engines. The OEM carb kit for them is easier to find than aftermarket kits or even whole carbs for some of the newer engines.


This is fairly easily remedied with some off-the-shelf bronze bushings (at least for the K241-K341 and KT-17 adjustable carbs).

I have this pile of worn OEM carbs I need to get fixed up and sold one of these days. All will need rebuild kits, throttle shaft bushings, and maybe a helicoil here and there.

I keep the cub cadet stuff on my shelf since I never plan on getting rid of them anyway. As the addiction goes sometimes there is simply a complete back up tractor around…or several in addition to the parts !

 

[hydroharry]

My 169 has the original Kohler #30 carb. I usually have to a needle and seat kit with gaskets ever couple years after it starts to leak around the bowl. I think this is due to me only running it once or twice a year. The last time I put the kit in I realized the main stem (where the jet screws in) was really corroding. I have a spare original #30 I'm keeping just in case that stem corrodes away, breaks off, etc. I suspect the corrosion is due to the current ethanol gas, but I do run the carb out of gas before I shut it down. Should I switch the the non-ethanol?

 

[-CӞ]

i do avoid ethanol fuel with my equipment, operating by the assumption that my equipment just wasn’t designed for ethanol-blend gas. my Cub, boat, mowers, stihl trimmer, stihl chainsaw, etc.
and like you said, i run ‘em dry before storage to avoid stale gas problems and varnishing.
in short, yes, i recommend avoiding ethanol!

 

[1811Cub]

If you can easily purchase it, buy the non-ethanol "Rec fuel".

 

[Jay Fetters]

Agreed, avoid ethanol in older equipment. For the equipment I don't use much, I've been buying vp engineered fuel. It is supposed to last 3-5 years, and I've not had a problem since I switched. Yes, it's EXPENSIVE, but in the equipment I use it in, it's cheaper than a carb kit and my time.

 

[dgeary]

I'm going to chime in on the ethanol vs non-ethanol topic. I live in rural Illinois where only gas with ethanol is available unless I want to drive an hour to find gas without ethanol. I even have to drive to find premium for my GN. With that noted, I have been running the ethanol gas in all of my vehicles and equipment for over 30 years. I have 3 tractors, power washer, push mower as well as 5 classic cars mainly Olds Cutlasses. All of those vehicles have carburetors. I have never had any issues related to ethanol in any of these vehicles.
I did have to rebuild the carb on my 129 when I first got it but that was mainly because the bore for the throttle shaft was so wore it was a major vacuum leak. I machined the body for new bushings and added a carb rebuild kit. That's been 12-15 years ago and I've only run ethanol gas in that since. It still runs well and I've not had to do anything to the fuel system since.
With all of that said and based solely upon my own personal experience, I'm not sure why folks think it's so important to run only non-ethanol gas in vintage equipment and vehicles. Maybe I've just been lucky?

 

[mgonitzke]

Yes, you have without a doubt been lucky. If the ethanol blended gas sits around for more than a month or two, it will absorb water, which will corrode the aluminum components of the fuel system. There are still a lot of gaskets and seals out there that are not compatible.

I have had 3-year old non-ethanol gas (with stabilizer) remain viable.

 

[Henry Leach]

Ethanol free fuel in my town is a dollar per gallon or more than is regular so I'm going to start using this stuff in my small engines and '76 Scout:
STA-BIL 360 Protection Ethanol Treatment & Fuel Stabilizer - Prevents Corrosion Caused By Ethanol Blended Fuel, Helps Increase Engine Power and Fuel Efficiency, Treats Up To 160 Gallons, 32oz. it's around $15 from Amazon. There are other brands available - this one gets over 5,000 five-star reviews and so I went with it.

 

[1811Cub]

I just had one of the plastic floats in the 1282's Chyna carb completely fill with fuel causing a severe flooding condition. Believe it or not, the old brass float from a Tecumseh 10hp snow king carb went right in and now it runs excellent again.

 

[Greg Riutzel]

. Maybe I've just been lucky?

I wonder if location has an impact. I know living in Western Oregon were humidity can be high and fluctuate rapidly, it can really affect fuels in vented fuel systems and tanks. We had a governor that pushed the green agenda pretty hard and all Oregon gasoline had to have alcohol. It raised hell with 2 cycle engines namely fisherman's marine/water craft and faller's chainsaws. He relented to let non-ethanol be sold at the dock, and then at the pumps for portable equipment. Pretty soon it started going into cars, classic vehicles mostly. I've had small engine shops and dealers say they witness the effects of E10 on older equipment so I took a proactive guard and not use it in chainsaws or small engines in general. My brand new Stihl equipment has it in the manual not to use E10. With the exception of 2 cycle mixes, I've used Marine grade Stabil with good results in vehicles that may set for weeks or months.

 

[rjruchti]

I have used nothing but 10% Ethanol since the day it come out. WITH STA-BIL . Everything for chain saws (3) trim mowers (2) line trimmers (3) riding mowers (2) garden tractors several, my truck, and everything else that uses gas. Not one problem in over 30 years. I don't store or park my equipment outside either and I think that has more to do with it than the blend of fuel.

 

[jstewart]

I went crazy using Sta-bil quite some years ago, put it in several of the H's..........................it seemed to glue the floats in place and I had trouble with the ones that had been treated, the tractors that weren't treated were ok.
Race/airplane gas is the only thing that stores well. The local Honda motorcycle shop stores their collection of bikes this way
The vapor pressure created by warm weather causes the lighter hydrocarbons to flash off, leaving the heavier ones behind, the medium hydrocarbons flash off at a slower rate, eventually leaving only the heavy ones behind...........eventually resembling tar......................there is just no way to stop that, controlling temperature sure does help.