I have been watching a lot of you modifying your quads with various set ups but as I check into pricing out some of the great stuff you all have the cost of upgrading your motors is way expensive. As I have a limited amount of funds to dedicate to my quad I was wondering if there are any mods that can be done to the stock pipe/carb/airbox that will give me improved performance. I have played around with removing the guts of my stock exhaust by I am unsure of the negative consequences associated with this type of messing around. Any comments or suggestions would be greatly appreciated.

 

Proper gearing and tires are the best thing for a stock DS. Try to just change the front sprocket and retain the rear, the aftermarket costs too much and aluminum wears quickly. Pipe mods work almost as well as an aftermarket slip on. A k&N in the box or on the carb and a jet kit with new needle is well worth buying. The response is much better and it wheelies easier.
I tweeked my ignition timing and port matched the intake and exhaust (make sure you don't get anything down past the valves) and I'm hanging with bikes with bigger carbs, exhaust and higher comp pistons.
I hope this helps, my DS was always a little slower than a few other guys I rode with and I have tried alot of litte mods. This is the best and cheapest combo I can come up with with the exception that I also have a cdi.

 

What front sprocket did you use and how did you modify your pipe? Yesterday I toyed with removing all of the guts and I ended up with a very rattly exhaust
Any more help in direction would be appreciated as I have no experience with tuning

 

Yup ditto what mystereid said. The porting may be a bit much for most folks to do. You can actually make it worse if your not carful.

You can get front sprockets at rocy mountain for about 13 bucks. Cheap mod and works great. K&N power kit comes with filter and dyno jet kit. ABout 100 bucks. Great investment. Leve the guts of the stock pipe as they are. Just modify the end cap. Or get one that has already been modified. The performace with the moded end cap has been said to be as good as the aftermarket slip on's only way cheaper.

 

I highly recommend the modified endcap. That was the best single thing I did to mine, but you also have to rejet. I really like my setup, and I try to keep everything as low-buck as possible. Hang around these forums, maybe you can catch somebody upgrading and get a good deal on their slightly used parts. That's how I got my jet kit.

 

What comes with 540HP stock? I have to know [img]i/expressions/face-icon-small-smile.gif[/img]

 

yea, was wondering teh same.

 

My endcap is just like stock but has the two little restrictors taken out of the tailpipes and two replacement tubes welded in place. This lets it flow better than stock but keeps the noise at 92 db for the Oregon coast restrictions and I kept the spark arrestor.
As for port matching, it's pretty easy with a dremel tool and a sanding drum. Pop the carb off and look in the intake, mine was missaligned to the head but ovaling the bolt holes in the intake fixed that. Then I attached and clamped the rubber boot to the carb and looked there. It matched up well until the clamp was tight, then it deforms and gets in the airflow. I sanded it and matched it until it looked right. Then I did the same with the rubber boot to the intake.
The exhaust ports are easy. Remove the exhaust and you will see where they have matched up with gaskets. Pull a plug and poke in a nozzle with compressed air. Bump the engine (ignition off) till compressed air comes out the exhaust and sand away without getting grit down the cylinder. Mine wasn't very missmatched.
My gearing is 14/43 now and works very well. Your gearing should be matched to your riding conditions, which are?

 

Ok here goes my mods, first if yer noise levels permit it of course just pop off the stock endcap and hacksaw off all the tubes and mesh stuff inside, i ended up with a very noticeable increase in bottom end---and it sounds exactly stock since i left all the packing in, i say leave the packing in because all it's for is noise control, and it does'nt hurt to be stealth with yer cheap mods, next i removed all the intake snorkle stuff, even the rubber tubes into the airbox, and while yer there chuck the lid too, add a k&n and you've basicly turned the stock airbox into a nice free flowing splash guard for the air filter.. all good, do the needle mod as in make sure it's not rubbin the side of it, and i increased the main jet to a 175 from a 165 stock. all in all it runs great and will wheelie nicely (i'm learnin still). oh yeah add a steering dampener, it makes the beast alot funner to ride all day, thats almost the most expensive thing i added so far. have fun and all that i've mentioned so far only costs less then $200, (dampener $150, k&n $45, jet $4) lates josh.....

 

I too want to know what has that much horse...[img]i/expressions/face-icon-small-happy.gif[/img]