Continuing Craftsman 18 HP riding mower issues

[user 64972]

I have had an issue with my Craftsman 18 HP riding mower with a B&S Intek motor. I bought an extended service plan that ran out a couple years ago. While it was in effect, the mower would sometimes feel like it had a miss and it would come & go. The service man said it seemed OK but suggested that I change the ait filter, fuel filter and he cleaned out the vent hole in the gas cap. I also replaced the plug and changed the oil & filter. It still had the intermittent missing after that but the service plan ran out. It seemed to be loading up when I let it sit and run and would get a rough idle.



A year or so ago, I had an issue again that was a little worse but still intermittent. Todd and some others suggested Sea Foam and carb cleaner. I did that and it still happened but less often and not as bad. I also replaced the plug, fuel filter, air filter and again changed the oil & filter. I also replaced the magneto at the time with a new one and it seemed to run pretty good until a month ago.



I would be mowing and it would get the rough running that felt kind of like it was missing. A couple times it just quit running. After I would let it sit for a while it would start up and not have any problems. Now the last couple weeks it has started the same thing but when I let it sit and then re-start it it will run rough and quits after a minute or two. It has had a new air, fuel filter and plug the last few years. I run Sea Foam in the oils and in the gas.



Any ideas....I hate to take this into the shop but it's getting to be leaf time and I pick them up for my relatives so i need the mower to be reliable. I'm thinking carb/fuel delivery issues...



Thanks for any tips (again),

Gary

 

[Todd Z]

Hows the compresion..... It maybe a piston ring issue ????



Try a thicker oil.... OR I would adjust the a/f screws slightly on the carb.... IT sounds like it gets rich or lean when it is warm..........



Or some fuel cleaner to try to clean the inside of the carb......



Or adjust the float in the carb, the needle and seat could be hanging up a little...



Todd Z

 

[Brian Curry]

Check valve clearance. Also check for blown head gasket around the area of the push rod gallery, common on ohv motors

 

[Bill Cooksley]

I would suggest pulling the carb. and look at the needle seat and clean the bowl set the float good luck. Bill

 

[David Watkins]

I've seen this before. water in the gas causes the float needle and bowl to get rusty and stick. This restricts the flow of gas and will run out after a minute or two. If you let it sit a while it will slowly refill with gas start right up but only last a minute. Clean out your float bowl and check the float needle.

 

[tom buczkowski]

Neighbor has same mower with same problems and it was a selonoid of some sort in the carb.

 

[David Clary]

Look in the gas tank and see if there is any floating debris. I had a piece of plastic, that I think came from my plastic gas can, that would float over to the hole for the fuel line and partialy plug the hole. There may even be something in the gas line that's flopping back and forth causeing it to block the flow of fuel. It could be the fuel line is collapsing, bad coil ect. My experiance is that it'll be something simple. Good luck!:wacko:

 

[Jim Johnson]

This may seem a little off the wall, but I've had similar problems with my mower, and it turned out that one or more of the various safety switches (seat, brake, blade engagement, etc.) were out of adjustment. Now, one of the first things I do in the spring before using the mower is to adjust those switches so that they work properly.

 

[Gavin Allan]

I got a big-a$$ John Deere garden tractor with a Kawasaki engine and have a trouble-free life now.

 

[Michael Cacioppo]

Gary G, it sounds like you are experiencing fuel delivery problems. The engine is requiring more gas that the system can supply at times. If you run out of gas in the float bowl, the engine will obviously stop. While stopped the fuel bowl will refill allowing it to restart. Your engine uses a fuel pump which uses the pulsation of the crank to pump the fuel. If you are pushing oil the pump will get some oil on its diaphram and reduce fuel flow. This can happen if the engine is getting too hot because of air flow restriction in the engine cooling shroud. Could be a mouse nest in there. Any cause could be a sticking needle and seat in the carb. I would look into the fuel delivery system for the problem.

 

[Keith McElroy]

I'm mainly a John Deere repairman, but the engines are all basically the same.



Check the clearance between the Flywheel/Stator and the inductor of the alternator. Many times the gap becomes too wide when the engine gets hot and the engine will stall. Once it cools, the gap is smaller and it will run again until it gets hot.



Rule of thumb for gap is the width of a business card. You should be able to adjust it by loosening the screws on it. I should point out that the engine shroud will usually have to be removed to get to it. It's an easy fix though.