How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask JohnF2015 Your Own Question
JohnF2015, Small Engine Technician
Category: Small Engine
Satisfied Customers: 1132
Experience:  Owner/Service Technician at S & J Small Engines
Type Your Small Engine Question Here...
JohnF2015 is online now
A new question is answered every 9 seconds

I have a cub cadet GT 50 inch 25 horse V Twin Kohler.

Customer Question

I have a cub cadet GT 50 inch 25 horse V Twin Kohler. Lawnmower has about 30 hours on it and is meticulously cared for. Three weeks ago it started quitting during mowing sometimes after a few minutes other times after an hour or more. I went and got a new gas cap from the cub cadet dealer. Mower has run perfect for last two weeks then yesterday it quit again. I opened up the gas cap put it back on and the mower ran fine for the rest of the day.I thought I had the problem solved now I am even more puzzled.Thanks for any help.
Submitted: 1 year ago.
Category: Small Engine
Expert:  JohnF2015 replied 1 year ago.

Hi, my name is***** will be assisting you.

How old is this machine? Is it a new machine? Or an old machine with really low hours or use?

Customer: replied 1 year ago.
2015 model
Expert:  JohnF2015 replied 1 year ago.

My first thought would have taken me to the fuel cap as well.

This fuel system most likely has an emission friendly vent system which means that it has a carbon canister vent system, if you happen to overfill the machine or get a lot of fuel splash the carbon canister will get fuel in it and can cause this type of issue. You can do one of two things if this is the problem: 1. Allow the carbon canister to dry out, it may take several days to totally dry out and run properly. 2. Replace the carbon canister, which can be rather expensive depending on which style was used.

The amount of fuel that you have in the tank will also determine how long the machine will run without issues as well. If the tank is near full then it will run a shorter amount of time than if it is half full or near empty. You have to be really careful to not overfill or get on to much of a slope with these new fuel systems or this is going to happen often.

Customer: replied 1 year ago.
I have some steep hills that I mow but it always seems to quit when I am on level ground. First time it happened I had only mowed about 40 feet then yesterday it quit after over an hour. I am also puzzled why it has ran perfect for the last two weeks mowing the same terrain then quit started immediately back up and never did it again yesterday.
Customer: replied 1 year ago.
It also ran perfect when I got it last fall.
Customer: replied 1 year ago.
Are you still there?
Expert:  JohnF2015 replied 1 year ago.

I am sorry I had to step away for a little bit.

It could have more to do with the amount of fuel that was in the tank when you started the machine. If the tank was full it would run a shorter amount of time, if it was half full it would run longer before creating an issue. It does sound like the fuel tank isn't venting properly and is causing a vacuum inside the tank after running for various times which is causing the engine to stall or die. When you remove the fuel cap you remove the vacuum which will allow the fuel to flow again and it may run a short amount of time or it may run for two hours depending on the amount of fuel in the tank and how long it takes until all of the air is used up inside the fuel tank and then the vacuum comes back and will not allow fuel to flow out of the tank again.

Customer: replied 1 year ago.
OK John now I have to apologize for being gone. I guess my next question is what should I do about the fuel tank not venting properly like I said it is basically a brand new machine.
Customer: replied 1 year ago.
Also John where is this carbon canister located and what does it look like? Thanks.
Expert:  JohnF2015 replied 1 year ago.

The carbon canister will be located in a line that comes off of the top of the fuel tank and normally runs back to the intake on the engine. If it is a matter of having fuel in the canister it will evaporate in a couple days and the problem will solve itself, if you need to replace it before that then you will need to contact Cub Cadet. I would recommend checking with a local servicing dealer since the machine is so new with very few hours on it, it should be a repair that can be done under the warranty.

Thank you it has been a pleasure to assist you.

Please take a moment to rate your experience.