I have a briggs and stratton 12hp i/c that i have laying around that burns alot of oil. the motor thats in my tractor know is a 8hp briggs and stratton. what i want to know is if i put the carb off the 12hp i/c on the 8hp will it have more power.. just wanted to know before i took it apart. thanks

I cannot speak as a qualified source, but since I see no other replies, I will give you my opinion. Carb venturi sizes are designed to handle a certain number of cubic feet of air per minute. Since I do not know how much the two engines require, based on the differrence in hp, I would think the 12 hp would be way to large to properly operate on the eight, therefore I would not suggest that you waste your time.

As tom said, don't bother doing it because the lowered air resistance through the bigger carb won't make any difference. It may even run worse...

well thanks for the replies. Just a random question and wanted to know if it would work before i changed it.. but another question,, i had the 8hp on the 12hp i/c because the 12hp one was messed up for awhile.. just wonderin,, thanks

Wouldn't work.... as for the engine using oil, you could either rebuild it or throw some straight 30 weight with a bottle of blue stp oil treament in it to slow it down.

can you tell me more about the blue stp please bugman. because i have a 8hp briggs that i really want to put in my tractor,, it only starts to smoke after about 15-30 mins. of use and it smokes when there is a load put on it.. plus just to add i had a string tied to the carb and was holden'er.. will the blue stp still work with straiaght 30weight oil in this.. plus it just smokes alot.. it doesn't burn a 20 ounce jug in 5 hours or anything,, i would really like to use this engine.. would this work bugman,, thanks for your replies

The stp is just a oil additive..... really all it does is add the antiwear additive zinc, and thickens the oil (alot)..... makes a 10w-30 a 15w-40.... so it might only need about half a bottle to make 30 wieght a 40 or so.