To start off i can't afford to buy another bike right now (getting my kid a 90 predator), i'll only buy a polaris so i'm adding more to my current bike. I trail ride and race in a flattrack series ( st and tt- won Utility class in 2001 and 2002), to race all i do is change the tires and rear shock. My bike( 1995 Xplorer 400) is currently set up as follows: AAEN mid/low end pipe and silencer, 0.060" over Wiseco piston,slightly ported, 0.10" off the head, #7 plug, Dual Stage reeds, 230 main jet, 35 pilot jet, UNI foam air filter- no snorkel and center down pipe cut in half, 1 lbs off the flywheel, starter removed, injector removed ( 50:1 with Klotz oil), HPD kevlar belt, middle of the color range on both trans pluntums, 30 tooth rear sprocket, 4 wheel drive system removed, Scrambler front rotors and brake lines. For racing i use 18.5" American racers T-22 on ITP rims all around.
Items i plan on doing this winter: 38mm TMX carb, Take the starter teeth off the flywheel (1/2 lbs) and reed cage spacers. Next spring i will mainly be running in the Open Amatuer Class on small tracks 1/8 mile to 3/8 mile and i am looking for upgrades that will work for trails and track. I need some input on trans upgrades that won't kill my top speed (around 80+)and anything you guys and think of. thanks
hunt

 

WOW
That is an awsome explorer.
Just a note on a few things

1.) The reed spacers you plan to install will mostly help Lower end performance. MORE TORQUE.
I think you could actually loose some topend.
2.)You are running a low/mid pipe. Have you thought of going to a topend pipe?
3.)Have you thought of going to a Higher compression race head?
4.) Rear shift drum conversion. I hear the Team Performance unit is the best on the market. AAEN and HPD also have a version. This will eliminate friction from you secondary, freeing some power in thery.
5.) Also I am just wondering, but my scrambler 400 came stock with a 230 main jet. Once I piped it that was too lean and required more fuel, I think I am running a 250 or 260 main.

Sorry, I can't think of anything else, that is one sweet explore you have there.

 

I've been out of the polaris net for a little while,but I seem to recall Mike or Modquad mentioning a bigbore power valved 440 or 411. I am sure that **** hauls from bottom to top.

 

Biggin had a good point.
If you want to Rebuild????????
AAEN has a 440 kit and a 470 kit$$$$$$$$
Also HPD has the new power max kit. It is for a Scrambler/sport but, if you called them thay may be able to work with you. The Powermax will require A LOT of changes, but BIG POWER.

 

I checked with AAEN on a big bore kit but you have to have an engine from 97' up. The 95' case studs will not handle the 440 kits. The torque is what i need alittle bit extra of to get off the line good. Most of the tracks that we run at is around an 1/8 mile with tight corners. Would you guy know of a steel braided brake line off of another polaris that could replace the rubber brake line from my master cylinder to valve block- model and year? I'm also looking for a "gripper" seat cover. thanks for the input .
hunt

 

You might want to check out www.rittercycle.com or call Rick directly. Maybe a more radical porting job is in order.

 

Better porting is my thoughts exactly. I see room for several improvements. Need more compression if any gas is acceptable. Need a top end pipe,and the clutching to match. That thing would scream out of the corners and keep pulling. You need the cylinder to flow better to make good power. PM me if your interested.Bubba

 

I've not noticed much attention being made to handling....

I like ceramic coated pistons. And for racing I'd get an EGT to get it jetted right. Lots of power on the table in jetting. The ceramic just is a CYA against them momentary lean.

The higher RPM suggestions might be right. From what I see now that I have a tach, and from doing some data logging, I sorta wonder what use the bottom end pipes are. Look at the dyno curve of the top end pipes and the low-mi-range pipes. The only time the hi-end pipe is LOWER then the mid-range pipe is below the RPM you're liking running at anyway.

Get a tach and go see just what rpm you really need to have the power at. I'm kinda think you'll find you're running more RPM, even when you think you're pulling out of a corner or jumping off the lines, then you think. I would be darn cautios on porting though, as that's a bit harder be put right if you don't like it.

 

dfischer, Do you know if an automotive tach would work ok with a quad or does it have to be a certain type/class? For racing alot of the tracks we run at are small - 1/8 mile or less with straights of 30 to 40 yards. So i'm afraid if i get a top end pipe i won't be able to fully utilitize it on the small tracks.
So far for handling i have done the following: Fox 1.5 front inserts, 2.5 rear spacers, banchee rear shock-very stiff,moose handle bars, front 4x4 system-rack-bumper taken off to lighten the front, new inner and outer ball joints, race with American Racers 18.5" tall on ITP rims softness T-22. I love to jump on the TT courses so i have not put a front stablizer bar on. by jumping i only mean 3 to 5 feet off the ground.
thanks for any suggestions, i'm just building as i go along.
hunt

 

kyxplorer, you cant think of the top end pipes like that of a manual shift transmission. A top end pipe makes more power at a higher rpm, but you change the clutching to match it. That way when you nail the throttle you are at maximum power and rpm,then the transmission just plays catch up to the engine. Your doing the same thing now, just not making the kind of power you want. You can NEVER go wrong putting more power to these machines as long as the clutching matches. Bubba