Riding mower woes...what's the science?

[KeithASanford]

I just spent my day in my backyard and on Youtube and Google, trying everything I saw and read to get my Mtd 13.5 HP mower to run. I'm not purely the mechanical type, but I'm a bit of a Zelic; I kinda become what I'm immersed in.

So I drained the old gasoline out, checked, drained and added new oil, adjusted the valves, bought a new battery and took the carburetor off and cleaned it and the bowl. I attempted to fire her up after each treatment and all I got was a strong turn but no start. I took the air filter off that I had cleaned in this process and shot some quick start in there and it started right up, but puttered out when the quick start burned. I was pretty sure it was the fuel not getting past the carburetor.

When I was servicing the carb, but I noticed when I had the float out of the bowl, I had no trouble blowing through it, but when the float was replaced, I could barely get air pressure through. The needle on the opposite end of the float is in good shape and the seat of the needle seemed to be fine as well, but somehow the needle sits too low in the seat, sealing the hole even before the bowl has fuel in it. I guess I will just get a rebuild kit but I was hoping someone could explain the science to me. I've seen the needle and seat leak, what would cause the needle to seat too well? Can the seat swell as it wears out?

It's a non adjustable Tecumseh Series 7 carburetor.

 

[us AAirways]

Did you try a new spark plug?

 

[docmirror]

Do yourself a favor. Get the unit number off the mfg tag under the seat, or on the back of the chassis and go buy a carb for it. Make sure the fuel is getting to the carb, and just replace the darn thing with a new fuel filter. Following that, when your last cut of the season comes, drain the fuel from the carb completely and run it dry, or add some Sta-Bilz to the fuel run that through. The Alcohol in fuel gums the carbs up each season.

 

[KeithASanford]

New spark plug, check. Carb ordered, check.

I will put her away the right way this fall. I was gonna buy a new one and something told me to try and revive her. I'm learning an awful lot, though.

 

[JHW]

forget the stabil, put it away with 100LL in the tank and carb

 

[Alexb2000]

New spark plug, check. Carb ordered, check.

I will put her away the right way this fall. I was gonna buy a new one and something told me to try and revive her. I'm learning an awful lot, though.

New plug but are you getting spark? Visually verified?

Air filter clean?

Exhaust flowing freely?

If yes to all, shoot a little shot of starting fluid in there with an open choke. It should fire briefly. If so then continue with a fuel system problem.

+1 on 100LL, best thing for small engines.

 

[JasonM]

Does your mower have an inline fuel filter? if so, go buy a new one at lowes and give that a go. I spent 2 days tearing apart a zero turn mower I have last summer to find that was the problem.

 

[Sac Arrow]

Totally a gas filter issue. Gummed up.

Don't run 100LL that will just foul it further.

 

[Foxhole]

I do a ton of small engines. Mowers, Trimmers, Blowers. Probably 5-10 a month. It has turned into a small side business for me. 90% are ethanol caused issues in the carb. It is much easier to order a new carb. Often the carb is about the same $ as a kit. Make sure you get the carb to engine gasket sealed. Some gaskets only go one way. I like to add a fuel filter. They sell a clear plastic filter at Lowe's for about $5.00 that is what I use. I also change all the fuel hoses when I am doing it. The ethanol fuel will degrade some of the cheaper fuel hoses from inside. Then you wind up with pieces of rubber goo in your brand new carb. I am religious about blue stabol. The blue is the marine grade and seems to last longer than the red stabol. Anything I can do to help let me know.