CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Garden tractor

I have a 1991 model 210-5 toro wheel horse garden tractor, and whenever I turn the engine over with the air filter off ( I have to do it pretty frequently because it usually won’t start with the air filter on) it will emit a sort of fuel spray out of the carb. it has been doing this for at least 5 years.

If it won’t start with the air filter on, then something is probably not right inside the carb. It may be clogged/gummed from years of sitting over the winter with stale gas in the gas tank/carb.

The carb may need rebuilding/cleaning.

What brand engine and what horsepower. Also, is the engine horizontal or vertical? My first guess would be a sticking valve but I won’t put any money on that.

If it won’t start until you take the air cleaner off, the card is too rich. Start by cleaning the carb and turning the fuel mixture screw in a 1/4 turn at a time until the idle quality degrades and then back it off 1/4.

Yep, by taking the air cleaner off, you are allowing more air in to lean out the fuel mixture. This means it is too rich. If you can’t adjust it down, you need to do a little carb repair. Just get the overhaul kit and give it a good cleaning. I think that would have been either a Wisconsin or Briggs engine. Piece of cake. Oh and get a new air filter.

It is a Briggs and Stratton engine, 10 HP. The odd thing is that when it is cold outside I can put the choke on and it will start very easily.

And the engine is a vertical shaft.

Engines need a richer mix when cold. So what is too rich with warmer temps might be closer to about right for the colder temps.

Took the carb off, looked at the valves, valves were in good shape. Adjusted the mixture, and it runs great. Thanks for all of your help!

Cold air is also denser therefore it contains more oxygen molecules than warm air.