I have an 03 Bayou 300 4x4, what can I do to increase performance (horsepower, torque, and such)?

 

a pipe and jet kit, filter upgrade and maybe a clutch kit if u have larger tires. if full time 4x4 try to find a warn 424 front drive shaft.

 

What about boring it out?

 

idk if boring would make the bike any faster maybe more lowend torque. the gearing is the hold back on speed. if u bore it u will need all the other goodies to go with it anyway, so if it has good compression and no smoke i would start with a pipe and jet kit

 

It does smoke! I've been told that I could've put to much oil in it or it could need new rings!!!

 

well since u have to go into it anyway have it bore 10 or 20 over ,don't get to radical cuz u will lose ridability

 

So I'll have to bore it?

 

Cycle Works Racing - The Trail to Your ATV Needs
can put a cam, jets, exhaust, big bore kit, carb, and anything else you want.

best bang for the buck is a filter and a dynojet carb kit.

change the spark plug every time you ride, watch the oil, and ride it till it can't start, even with a new plug, and THEN rebuild it.

if it won't start, swap the plug, first time.

 

Seriiously, there aren't many aftermarket performance mod parts for Bayou 300 out there. Don't get me wrong - the 300 (air cooled 5-spd semi-auto) is a well made machine for its time and does its job wonderfully for what it is. It's just that it is outdated (first came out in 1986, maybe older than some of you) and not popular anymore. You are pretty much on your own to do experiment to find out what works or not, backyard engineering. I would just keep it stock for reliability, save money and use it to replace with more recent/popular quad.