modding briggs ohv 800 series, help?

[fox440]

so the engine still backfires when i let off the throttle. what could it be? lash is good, no vacume leaks, no leaky exhaust... im lost

 

[fox440]

well i put on the stock carbuerator and it ran great. it didnt backfire at all. so there is somthing wrong with my animal carb. what could it be? would the float maybe out of adjustment be causing it? to big or to small main or pilot jet? any help is appreciated!

 

[Le Plat]

did it back fire only when reving or when u let of the gas??

 

[fox440]

it wouldnt go up to high rpms it would just sit there and kinda backfire and pop, the when i would let off the throttle it would back fire to. but now with the stock carb. it does none of that. im lost?

 

[5 Horse Fan]

High RPM backfire is usually cause by a lean mixture condition.
You need more fuel at higher rpms.

Not enought valve lash could cause that too.

 

[fox440]

yah.. i know its not valve lash tho because it dosnt do it with the stock carb...

 

[5 Horse Fan]

yah.. i know its not valve lash tho because it dosnt do it with the stock carb...

Well, without a Tach, you don't know if you are exceeding the rpms of the stock carburetor.

 

[fox440]

huh? i dont think u understand. with the animal mikuni carb on it it backfires but with the stock carb on it it dosnt..