New Carburetor

[dodge man]

I’ve had replacement carbs not work well. I know one on a Lawn Boy tan terrible until I switched a jet with the original.

 

[EddieWalker]

Update on the carburetor for my Scag zero turn. It's worked great until it wasn't. I was actually enjoying mowing again. It fired right up, and had tons of power.

Amazon.com

Then things started getting weird again. It wouldn't start after running it for an hour or two. Battery is 4 years old and kept on a trickly charger, so I'm thinking it's at the end of it's life. I just want to make it through mowing season and I'll buy a new one in the Spring.

But then it started missing while mowing after just an hour. So I parked it and tried to figure out why. Eventually it was happening even sooner, and I couldn't get it to start. It felt like I was running on one cylinder.

I took the cover over the carb off that connects to the air cleaner and it was soaked with gasoline. I'm thinking that the needle is stuck and I'm flooding the engine. I took the carb apart, moved the float up and down a bunch of times, and watched the needle go in and out without any issues. I put it back together and it fired right up. I mowed for a few hours, and it worked perfectly. Tons of power, very smooth and like brand new again.

So now I know what to look for and how to fix it. Sort of. I'm not sure if it's a bad carb, or I'm getting something in my fuel, past my brand-new fuel filter. If it happens again, I'm leaning towards buying a different carburetor.

 

[ultrarunner]

Carb replacement is number one for the mower shops here… the fuel we have plays havoc with pot metal carbs…

I’ve had to do several myself and picked up some good equipment for free that a carb change cured…

There is some talk the ethanol mandate might go away… it would be wonderful for small engine owners because ethanol free is only available at $30 a gallon from stores where I am…

 

[EddieWalker]

It's probably only been a year or so since I started buying ethanol free gas from the gas station for my small engines. I'm sure that the original issues with the carburetor on my zero turn is from the gas I used to use.

Right now, regular gas is $2.52 and Ethanol Free gas is $3.23 at the gas station that I usually go to. There are half a dozen locations in my area that have it. I've noticed more power and easier starting with it, especially in my generators and log splitter.

 

[ultrarunner]

I filled up with Ethanol Free in Carson City Nevada and recorded the highest mpg ever but as I was going down the Sierra to sea level. I can’t know how much improved mpg resulted from ethanol free?

I do know carbs were worked on or replaced when they wore out from years of use and now they never wear out as corrosion takes them out.

Maybe this is the plan…?

 

[oldnslo]

Update on the carburetor for my Scag zero turn. It's worked great until it wasn't. I was actually enjoying mowing again. It fired right up, and had tons of power.

Amazon.com

Then things started getting weird again. It wouldn't start after running it for an hour or two. Battery is 4 years old and kept on a trickly charger, so I'm thinking it's at the end of it's life. I just want to make it through mowing season and I'll buy a new one in the Spring.

But then it started missing while mowing after just an hour. So I parked it and tried to figure out why. Eventually it was happening even sooner, and I couldn't get it to start. It felt like I was running on one cylinder.

I took the cover over the carb off that connects to the air cleaner and it was soaked with gasoline. I'm thinking that the needle is stuck and I'm flooding the engine. I took the carb apart, moved the float up and down a bunch of times, and watched the needle go in and out without any issues. I put it back together and it fired right up. I mowed for a few hours, and it worked perfectly. Tons of power, very smooth and like brand new again.

So now I know what to look for and how to fix it. Sort of. I'm not sure if it's a bad carb, or I'm getting something in my fuel, past my brand-new fuel filter. If it happens again, I'm leaning towards buying a different carburetor.

Eddy,
If you take the carb apart again look closely at the float pivot points and where the or how the needle connects to the float. It is not common but there can be small burrs on the carb casting catching on the float or sharp edge in the pilot bore for the needle that when moved just right cause it to bind.

What type of filter is on this machine? Simple screen meant for gravity feed systems or slightly better filter meant for fuel pump systems?

Haven’t read the whole post but presume you checked valve clearances. Reason for asking is that I would expect a flooding carb to affect both cylinders unless the is a double barrel carb like used on some Kawasaki engines.

Either way random problems are a pain to fix.

 

[EddieWalker]

The fuel filter is an inline paper type of filter. I also drained the tank and then added a little gas back to it and sloshed it around several times to get anything that might of been in it. I never saw anything, but I wanted to eliminate it as an issue. I have two fuel tanks, but when I replaced the fuel lines, I only ran it from the tank I always fill up. The other tank is capped off and empty.

If it happens again, I could look for burs or something catching the needle or the float. It went in and out really easy, so it's not going to be easy to find if that's it.

I haven't messed with the valves. Once it started up and ran with the carb back in place, I figured everything else was fine.

 

[oldnslo]

Do you have a compression tester? Sometimes if valves are the problem you will notice a change in compression from cold engine to hot engine. Non invasive test that might provide some info.

Agree on it started an ran so why look for other problems or worded another way, don’t fix what isn’t broke…

Wish you the best on getting that random issue resolved.

 

[anomad]

The fuel filter is an inline paper type of filter. I also drained the tank and then added a little gas back to it and sloshed it around several times to get anything that might of been in it. I never saw anything, but I wanted to eliminate it as an issue. I have two fuel tanks, but when I replaced the fuel lines, I only ran it from the tank I always fill up. The other tank is capped off and empty.

If it happens again, I could look for burs or something catching the needle or the float. It went in and out really easy, so it's not going to be easy to find if that's it.

I haven't messed with the valves. Once it started up and ran with the carb back in place, I figured everything else was fine.

I went through a similar experience with my old Wright. Put a cheap amazon carb on it (it was a kit with all the fuel stuff). Ran great for one session. The float failed while parked and it pee'd all the gas out. Replaced the aftermarket float with the original and was back in business for a while.

 

[WinterDeere]

I invested in an ultrasonic cleaner. I have put in carbs that I never thought would run again. Varnish build up due to ethanol is what was killing my carbs.

More often on 2-stroke carburetors, it’s hardening of the rubber diaphragm that meters fuel, caused by ethanol. Soaking it in 2-stroke oil or even non-ethanol fuel usually gets it pliable and working again.

Savings one carb pays for the ultrasonic cleaner.

I wonder if the chemical in your ultrasonic has the same rejuvenating effect on rubber, as non-ethanol fuel?