The list of improvements done to my wifes quad:

Added a rear shock from a mid 80's cr80
Alum wheel spacers, 1" per side in rear, 1.5" per side in front.
Modified answer S/A pro muffler and bracket.
Replaced all wheel/axle carrier bearings.
Added UNI air filter.
Added ice chest to rear grab handle.
New disc and chain adjuster guards.
New chain guard on right side of quad. (I just hated the stock one)

 

The aftermarket exhaust I bought came with the i.d. the same as the exhaust port, much larger than the stock one.

The work I did to the head was milling .035" off to boost compression, because I switched to a head with larger valves and larger combustion chamber it lowered compression. Milling the head will increase that bottom end grunt making it accelerate off the line and climb better. raptoraz milled .050 off his stock head with good results also, I haven't had any problems with detonation. I doubt I will even when summer gets here, these air cooled engines run hotter so there is a limit to how much compression you want though.

Also, I did some porting, smoothing out a lot of machining around where they machined for the valve seats and the intake and gasket needed matching.

There is NO hill it will not climb now, except where traction is limited. Keep in mind my buggy weighs a little under 500lbs so I am pulling a lot more weight, you may not even need to do that much to yours unless you like to tinker like the rest of us!

I know my stock intake was very restrictive, the tube running from the airbox was a bottleneck, the kit I got completely replaced this with a large tapered steel tube. I have noticed when I remove my air filter it makes no difference in jetting, when I remove the metal tube though, it does. You would think the air filter was more restrictive than the tube alone but not so. So there must a large improvement when replacing the stock skinny rubber tubing between the carb and filter. Then again I'm no expert, I hardly even have time to tinker anymore.

mywifesquad, don't you know those bikes are gonna get you hurt! my left shoulder is hurting right now! Not that quads are any safer (I prefer bikes). My son is already asking for a motorcycle and he still has training wheels on his bicycle.

 

Kell, I have been riding on 2 wheels since 11, I am now 45. I dont want to offend anyone, but I am not old enough for a quad yet.v I still havn't even broken a bone yet. I made it to the A class in enduros at 23 and even rode a 2 day qualifier once for fun. At this point in my life I know how fast i can go in any situation and pretty much dont fall down at all. i am way too old to go for that if your not crashing your not trying hard enough line. At my age i think if your falling down a lot you need to move onto something safer. The little woman even rode dirt bikes until 4 yrs ago. Turned 40 and didnt want to even have the opportunity to fall down. She had broken her shoulder, not on a dirt bike. And that shook her up a little too. I still feel safer on a dirt bike at speed than on a quad, i dont need to hunt for such a wide line. Main thing is that i still get the same feelings (Rush) on a db that i did 31 yrs ago on my first 2hp no suspension mini bike.
I told my boys no db until they could ride a bicycle with out training wheels, oldest did it by 3 yrs 3 mos. That still amazes me to this day. Kid really wanted to ride bad. Never wanted to even deal with the whole CPSC nonsense. I did build them a 2 seater mini buggy that was fully caged, seat belted, fully padded inside. Powered it with a 2 stroke chrysler honey bee 5hp motor. ran a jack shaft and geared it way down and put a throttle limiter on it. At first it only went about 10 mph, at the end it was up to around 25 mph. made a steerring setup like a honda odysey but used a throttle to train them young.

 

I tried the quad thing for a while and found out you have 4 wheels to hit bumps and ruts with, very punishing. I kept thinking if I had a dirtbike I would be ramping off everything in the trail! Went to a motorcross race when I was younger (I'm now 36) and quickly found out I wasn't in as good as shape as I thought! I then took up mountainbiking to get in shape and got sucked into racing that. Had a good time, most of those people have no idea how to ride fast downhill, course, they would kick my you know what up the hill! I did well on that, and still rode dirtbikes then got into road racing and that was a money pit. Only got a broken rib out of that. My absolute worse crashes have occured on bicycles. I literally nearly broke my neck, well that was enough, the Lord was definetly telling me something at the time and I had to give up all that garbage. My finger is still numb on my left hand, I couldn't do a decent push up for a year.

I keep trying to sneak bikes back in, my last one was a ttr125L yamaha that I was going to race in the maddog (middleage guys like me on small bikes) flattrack and tt races. I always liked cornering and passing better than those ridiculous triple jumps at a track. My wife made me promise I wouldn't get hurt and next thing you know one of the guys breaks his ankle really bad so I sold that. I never learn.

Now I have a super happy family fun machine that I can take my oldest boy along and enjoy my family! (and no more knee and shoulder injuries)

I know what you are saying about knowing your limits and riding in them, I just always had a problem trying to ride right there all the time. In conclusion, I really don't know what the huge quad craze is about, you can take a bike and run twice as fast, twice as cheap, less garage room, I could go on and on, however I do like sliding sideways, and a quad gives you that car like dukes of hazard sliding everywhere feeling.

(hope I didn't offend any quad riders, I still like them, I like just about anything with and engine and wheels)
Kell

 

I have absolutely nothing against quads at all, to each their own. Just have been able to as you say ride within my limits. Even when racing enduros occasionally now. It is when i fall down 95% of the time, I just push more racing than I do riding. What I get my biggest rush from now is saving a crash. When you have fallen as much and as many ways as I have in my life, you learn a few tricks along the way. For me the best part has been going camping riding with the wife and boys all these years. Sons are 17 & 19, oldest just got married in jan. Both still ride, were going out tomorrow for the day. The "new wife" has 2-3 times on the mini trail and is hooked, her dad is speechless over it. Just cant believe his daughter would want to ride off road, pretty cool I think.