I have a 110cc carburetted single cylinder engine. I've been trying to sell it for some time, and well, I can't.

I might as well use it for something, but it's putting out 7hp with a 4-speed gearbox.

Long story short, what are some good ways of increasing the power?

On a car, sure, you can throw on some bigger fuel injectors, a bigger carb, better heads, ect... but you can't really do that with a single cylinder.

And no, I'm not looking to throw nitrous on it.

2 or 4-stroke?

Advance the timing a couple degrees. That and a tuned exhaust.

Skimming off some of the head should also help boost the compression and power. Flatheads aren't exactly known for their high compression ratios. :D

If it's 4 stroke, you could explore boring it out .30 or .40 over. Install bigger valves and rejet the carb.
Maybe get a better flowing muffler.
Anything more probably isn't worth the money.

Titanium valves for sure.

Up the compression by milling the head as much as possible and shape the piston to match the head shape if possible then leave an area for the spark plug so they dont hit. Run like 15:1 with octane booster thatll make killer power (and be a bitch to start)

Go to pick a part and see if you can rig up a turbo froma 1.8L orsomething lmao.

SUPERCHARGE THAT MOTHERFUCKER.

Yeah!

Bore it out, exhaust/intake (ports and filters and pipes) increase compression by shaving down the head or domed piston. Change or rejet the carb. Bigger valves. Advance timing a little.

Not worth it. Is this a bike we are talking about? Use it for a small bike or go kart, but it will never be fast.

I happened to be reading this webpage last night :http://www.dansmc.com/hopup.htm

I am assuming the engine is a 4 stroke.

boring the cylinder out seems to be the number 1 option however maybe bigger carb would work well or you could "grind the heel of the cam." I find it hard to believe it only produces 7hp, that is a pretty measly amount of power. Straight through exhaust could maybe work too?

Is it running properly now?

Check that the valves aren't pocketted, check your valve clearances, check your main bearing, convert to a needle roller if you really feel like dicking around.

Port the head and the carb manifold to suit. An exhaust. Bore the fucker out. Bigger carb. Cam regrind. Get all of your tolerances correct. Either skim the head to raise the compression ratio or get a forged piston. Balance the crank + rod + piston. Lighten internal gears. Cut off your valve guides in the port.

There's a little bit. You can go further if you feel like it.

http://www.bikesales.com.au/as/search/sd.do?recIndex=11&modelID=9&makeID=2&page=0&selectedModelIndex=1&y=5&selectedMakeIndex=2&previousResultPerPage=20&currentPage=1&x=60

what do you think intravenous? it's that or the 250 version im picking up. been riding for years but this will be my first road bike.

Don't get an RS250, the VJ22 engine loves eating its powervalves. Having said that, I own an RS250, ahah.

If you can handle the maintenance, you need to open the powervalve cover after every few rides to drain the gunk out if you don't get aftermarket vented covers from somewhere like thetuningworks.com, as well as the usual two-stroke related bulljiggery, then the RS250 is a brilliant sportsbike. They make you work hard but if you can keep the revs between 8-11.5k then you won't find bigger smiles on any other bike. I've seen 230km/hr on mine, with just a set of expansion chambers, centre-fire plug heads and single-ring pistons. They are not a bike that you can ride to work everyday though.

I'm not sold on the RS125 to be honest. I've heard some not so pleasant things about the build quality on them.

Have you considered:
http://bikesales.com.au/as/search/sd.do?recIndex=2&modelID=882&makeID=42&page=0&selectedModelIndex=130&y=6&state=-1&selectedMakeIndex=44&previousResultPerPage=20&currentPage=1&x=62

http://bikesales.com.au/as/search/sd.do?recIndex=6&modelID=576&makeID=37&page=0&selectedModelIndex=134&y=16&state=-1&selectedMakeIndex=37&previousResultPerPage=20&currentPage=1&x=37

The VFR particularly is an outstanding bike man. Miniature RC30, and the fucker will never die.

I have looked at the kawasakis but not the VFR's. the only honda i have looked at was a cbr250rr which i did actually like.

I have also had a look at this one http://www.allclassifieds.com.au/ac/ac0036?bcid=122142065

thanks dude I have my gear, but I'll read up n have a serious look at the VFR's.