Snowblower evaporative emissions retrofit

Question

We have a Murray 1695539 snowblower. Problem is, while it runs fine, when we store it in our (attached) garage, it emits enough fuel vapor that the whole garage, and the breezeway between the garage and the house, reek of fuel, and we even have smaller quantities of fuel vapors entering the house itself. Is there anything we can have a mechanic do, aside from thoroughly checking the fuel system for leaks, to wrestle this beast's evaporative emissions into submission?

(Also: storing it in another place is impractical -- the only other enclosed storage we have is a shed in back, and it'd be massively painful to try to drag it all the way from there into the front yard whenever we use it.)

Answer 1

I would ordinarily recommend closing the fuel valve and running the engine until it stalls after a snowblowing session. This uses up fuel in the carb's bowl, which will otherwise evaporate and make its way out the air intake.

However, the manual for this model reveals that there is no fuel cutoff valve between the fuel tank and carb. This means that fuel evaporation from the carb bowl will take place continuously, and any evaporation will be made up by new fuel from the fuel tank due to the normal function of the float and needle valve. So it will stink of fuel until all the fuel evaporates and the tank is empty after several months.

You're asking about a retrofit, so see if you can dismount the tank and install a cutoff valve somewhere inline between the tank and carb. It can be any fuel-resistant valve, such as one that is used on other outdoor equipment.

If necessary, you can mount the valve some distance from the tank as long as it remains below the tank and carb level, and run tubing to and from the valve as needed.

Answer 2

The easiest thing you can do is remove all the fuel which is in the tank, then run it until all of the fuel is out of it before you put it in storage. No fuel; no fuel vapors; no fuel smell.

Realistically, you shouldn't be getting any fuel smell from the snowblower when in storage, with or without fuel in the tank. I keep my snowblower in my garage during the winter months and never have the issue of gas fumes. This leads me to believe there's probably a leak which you aren't realizing is there. You may want a mechanic to take a look at it and see if there's an issue.