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Lawn Boy mower question!


LawnSite Member
I have a 2 stroke silver series lawn mower that is about 4 years old. I noticed last year and the start of this year that sometimes when you start it, it will shoot gas out the exhaust for ten seconds or so. It also leaks gas out the exhaust hours after im done using it. I dont know if this is a stuck float or what the deal is. ANy help on this problem would be appreciated.:usflag: :usflag:


LawnSite Member
Pittsburgh Pa
No matter what fuel and oil will get into carb. and this will cause smoke to blow out of muffler. I have seen this year after year and all I run is Lawnboys, nothing to worry about yet.


LawnSite Fanatic
Sounds like your float needle valve is not closing (trash/stuck) and filling the cylinder with fuel.

Remove the carb. and take the float bowl off. Check the float valve for trash or wear, clean the whole carb. out with carb & choke spray cleaner then re-assemble. Also check the fuel tank for trash and clean if needed.

Install a fresh plug and you should be off and running.


LawnSite Member
Ozark, Thats a classic lawnboy problem. Do as restorob says then add an inline fuel shutoff. I assume you are working on the duraforce engine? There isn't alot of room but it should fit fine. When you are done mowing shut the fuel off.
Other option is to rekit the carb.


LawnSite Silver Member
Don't stop with a needle and seat repair. No LB carb(with the exception of the Walbro equipped models with plastic floats) rebuild is complete without a float replacement. After continual exposure to gasoline the cork will expand, thereby allowing the float to contact the carb body before the fuel is effectively shut off. If you compare a new float with the one removed you may find the old one to be nearly 1/8" taller.