Well It is the 500 4-stroke version of the 400 scrambler, ithink its a scrambler[img]i/expressions/face-icon-small-happy.gif[/img]

Anyway my brother owns it, and last night we put a pipe on it, and kow I want to know what jets to put in his carb(what size carb does this thing have anyway). and what would be the best mod to the Airbox(we dont ride in water) LID OFF??? SNORKLE ONLY?? VENT HOLES?? what?? we are about at 1200ft above sea-level. The pipe that was put on is pretty loudand moves alot of air, so we should be able to get by with the biggest jets a stock motor can handle.

Also, do any of you have or can recomend a clutch spring that will give him the best low to mid power? we ride mostly SAND dunes so top end is not important.

If anyone has such a spring that they can part with , he will gladly pay you what you think its worth. I am trying to get his quad at its potential before he goes looking to the aftermarket.


He is a big guy 300+ lbs so you can see why he needs all the power he can get[img]i/expressions/face-icon-small-cool.gif[/img]







thanks,



Bigger.

 

Yes, the 500 4 stroke is still a scrambler. It has a Mikuni 40mm BSR carb. What kind of pipe??? I have the full HPD Powermaxx exhaust. It came with a 165 main jet and turned the air/fuel screw (???) 3 turns from lightly seated. Most people on here that get the mufflers run a 160 main jet. I would start there and check your plug. As for the air box, Don't run it with the lid off. It will run like crap. Get the HPD air box mod. It is worth 2 HP and comes with everything to recalibrate the carb. Since he is such a big guy[img]i/expressions/face-icon-small-happy.gif[/img] he could benefit more from a full clutch kit. I would reccomend the HPD aggressive clutch kit. It comes with springs, weights, and a helix. Mine will wheelie like mad now

 

BigBad,

We when to the local Atwoods,and bought a TRACTOR muffler that fit our specs, it is 14 inches long about a 4" canister, and it fit the stock header pipe excellent, NO welding of any sort took place. The quad sound loud but good, those motors rev pretty quick! I was alittle surprised. Know I want to modify his air box, and jet his carb.

I have the 42mm BSR mukuni that cam off my DS650. I may try to install it on his SCRAMBLER(thanks[img]i/expressions/face-icon-small-wink.gif[/img]) I will tell him to order the HPD aggressive clutch kit. does it leave a large stall before engagement??



thanks for your help!






Bigger.

 

The 42mm should work. A few companies use to offer them but stopped because it was a pain in the **** to jet properly. I dont have a tach but would say that the stall is around 2500 rpm... just a wild guess. As for the jetting, I would try a 160 main and se what that does for ya. I am sure that if you made your DS a little faster than DSMike, then you know a lot about carbs. Unfortunely, I don't. But a 160 main should get you in the ballpark and you can mess around witht he air fuel screw as well. The 500 scrams don't liek to run well without the lid. You can get a lid modification from Hot seat perfromance and do the 42mm carb though. Or some uni vents may help.