Snow blower Toro 721 stalls when wet

naimc wrote: ↑ Have a problem with my Toro 721. I keep the blower in my garage at room temp about 12c. Blower always start on 1st pull when warm my dry. The stall issue occurs during big snow falls, ie winter storms after I bring blower in, covered with snow, for a few hours and it has not fully dried out. I will bring it back out, start it , and it will we run for 30 seconds to 1 min before stalling, like a lack of gas, pulling choke out half helps it bit but it will still stall. I cleaned the carburetor a month ago , change the spark plug and have been adding Seafoam to my gas.

Last time I used the blower in same conditions, a few hours after it was still wet the same issue occurred.

When I just use the blower and fully let it dry out no issues after.

Any ideas on what I should check next ?

Gas vent blocked by ice?

Carb icing maybe?

When you took it apart, did you notice a sheet of rubber under the outter housing that the choke pokes through? That keeps moisture out and off the carb

With it being fine when dry, I'd check the ignition side, how's the insulation on the spark plug wire & boot?

My 721 also stalls when theres a lot of snow and im trying to clear it and when i put the neutral lever out.

Thank you all for the suggestions. I will be taking my blower apart again soon. The 721 is covered in a plastic and has to undressed before anything meaning full can be done.

Suggestions from this thread :
Gas vent blocked ? -- A Not sure what to check this would be something on the gas cap ?

Carb icing - When you took it apart, did you notice a sheet of rubber under the outter housing that the choke pokes through? -- A I only took the bottom bool off, given it was very clean I did not take the entire card appart which is something that is on my list if simpler steps don't resolve the issue.

With it being fine when dry, I'd check the ignition side, how's the insulation on the spark plug wire & boot? I was getting a good spark and I also replaced the spark plug the 1st time issue occured. ----- A Next time I should spray some WD40 on spark plug to see if moisture related. Or wet the entire blower when running it see if it stall ?

Everytime I play with carburetor I get gas everywhere. I ordered some parts to put a T in the gas line, which will allow me have shut-off and drain connection. The valve kit came with a fuel filter which I also will be changing

I have to jam everything up in here :


I am wondering if the stalling problem might be caused by a dirty fuel filter.

I also called a local Toro repair shop and was told that a worn drive belt could cause stalling :



The belt looks ok to me.
When I opened the unit when the motor was stalling I did notice some water in here due to condensation and melting snow. Still don't understand how something wrong here could cause the motor to slip.

When wet, runs for 30-60s before stalling? Sounds a LOT like fuel delivery issues, and since it normally runs fine, it DOES kindof sound like the gascap isn't venting (or wherever that vent is).

Next time you have this issue, after it stalls, try to start it; hopefully it starts for a few seconds then stalls again (or just won't start). Open the gas cap (you might hear a lot of hissing air), and re-tighten it. If after this you get 30-60s more of runtime, it's almost definitely that vent (or, again, an issue with the vent if it's somewhere else), and you could potentially resolve it by wiping the snow off it before storing.

And the resolution to to problem : Fuel cap ( Which of a few of you suggested spot on !)

I tried out the new Tee drain I installed to empty fuel tank without a fuss. Fuel is barely making it out, un tighten the cap and we have a flow.

OP, can you please show how you install the Tee drain and where did you buy that Tee drain? -- thanks
I have the same Toro and would like to do the same on my machine.

I should have visited a shop where the fix snow blowers I might have found only the parts I needed.
I just bought everything online and at the time purchased what available on Amazon.

Could not find a single T so I purchased this kit :
https://www.amazon.ca/gp/product/B002ET2LLQ

This for the extra fuel line and shut off valves, I purchased this kit :
https://www.amazon.ca/gp/product/B07CJZK8VH

I used the two valves one right after the tank and the other after on the bottom of the T. That 1st valve is currently un- accessible without removing the cover, I will cut on round hole in the plastic to access it.
I change the route of fuel line as the original line route is too close to pull cord.

OP, thank you very very much, I'll try to do the same.
But why you put a fuel filter for your drain hose?

tsatsa wrote: ↑ OP, thank you very very much, I'll try to do the same.
But why you put a fuel filter for your drain hose?

Here is my detailed plan. Don't laugh it took me hours to draw at scale.

The fuel filter is on the main line, I replaced the tiny one that is allready on the line with one I got in the kit I linked.



The part you see sticking out is the bottom of the Tee and final drain valve.

Thank you OP.
I'll try to get some of these parts and do the same for my machine.
thanks again.