Somewhere at home I have the jet size charts for the horsepower levels for both the nitrous and additional fuel... it would be real easy to add 10 or more ponies to your engine as long as you have
A 12 volt power source... any small battery will do, as long as it can make it down the track a few times between charges
A set of nitrous and fuel solenoids... they do make some nice small ones now
A set of fogger nozzles, 1 for fuel, and 1 for the giggle gas
The RIGHT size jets for the horsepower level you're after, and Yes, you can drill your own
An electric fuel pump capable of 4 psi
a nice blue bottle in the smaller size... They make small 1 1.5 and 2lb bottles that are Easily hidden under a motorcycle tank or seat...
10lb bottle will last about 120 seconds at a 100hp boost level so if the math is correct, a 1lb bottle would give about the same for a 10hp boost... I could be a little off on those numbers since it's been forever since I messed with nitrous, but that's a close guess...
With the nitrous to horsepower level charts etc, it's real easy to manipulate the math for small engines where you wouldn't want to boost like 50hp from a Briggs... it would be fun as **** for about 3 seconds tho, but common sense...
You could try looking on some of the nitrous kit sites to see if they post the power level charts and jet size charts for the fuel and the nitrous, and from there it's not too hard to design a setup. Try NOS, Zex, Top Gun, Nitrous Works, and Edelbrock's sites to see if they got the conversion charts... Somebody's gotta have them online