backfire

[C&C Lawn Care]

i recently got a toro 42" ztr with a 16hp b&s and everytime i turn it off when its good and warm it backfires does anyone know how to stop this? iam using 93 unleaded gas. also it is the only one that i have that does this. Lets hear so ideas!!!

Thanks

[Aproct]

Let the engine idle down before turning it off.

[C&C Lawn Care]

doesnt work i have tired that time and time again!

[Aproct]

huh....I usually find that to be my problem...maybe running to rich..why are you running 93???

[C&C Lawn Care]

thats what i run in all of my equipment, do you suggest other?

[Aproct]

I usually only run 87 and really don't have any problems..Also, it is a heck of a lot cheaper.....1.84 compared to 2.20 to 2.25 for 93

[budrock]

Check spark plug gap. could be a quick fix

[C&C Lawn Care]

thanks for all the answers, i'll check as soon as the guys get back with it!!

[hardboiled]

Maybe the idle speed is set too high.

[C&C Lawn Care]

it really doesnt seem to be, but this is my first 16hp b&s

[shortgut]

backfiring

try this idle it down and then increase throttle just a bit above idle and see if that works let me know if it does or not hope it helps Tony twjshortgut@aol.com

[hardboiled]

Just wondering if you solved the problem yet. My 12.5 Kawi will sometimes backfire, if allowing to only idle for a short period, like less than 30 seconds or so after a hard run. The book say 2 minutes, I think. It takes a while for things to heat soak and stabilize without a cooling system(antifreeze). You may just have to give it more time to carry the heat away from the cylinder head and valves via the oil and air cooling. One thing you might try is a synthetic oil of the manufacturers recommended grade. It will most likely allow the engine to run a bit cooler and cool down quicker. In two different v-twin motorcycles I've owned, switching to synthetics has made a difference with performance, particularly where carburation was concerned. On one it stopped the cooling fan from having to come on all the time, and it ran better when hot. On another it removed an annoying stumble on acceleration from part throttle when hot. I'm convinced it was due to the better cooling properties of the Amsoil in both instances.