i have a 400 explorer and i was wanting to make it faster by adding all the stuff for a 60 horse kit until i read were someone with a scrambler had similar mods and kept burning his engine up at half throttle.is this common or was he tuned wrong?i want to be faster but i dont want to rebuild it after every ride.

 

The 400 2 stroke engine in the Xplorer is the same as the 400 2 stroke Scrambler. I have seen an after market pipe for this but can't remember the name nor company. Let me do some research and I'll get back to you. Vforce Delta Reeds, K&N & Pipe will really wake this beast up. If and when you do a top end rebuild, do a porting job on the jug to add some HP's also. My price was as follows:

HPD Pipe: $179
K&N: $35
VForce Reeds: $149
Self Porting: FREE

Once you get the upgrades done, you'll need a clutch kit to really plant the added power. And yes, you'll have to rejet after a Pipe or K&N. Sound like that other guy was way (SUPER) lean if he blew it up after half throttle. I've only blown my scram up once, that was due to a piston failure - stock I might add. Since the Wisco, no issues for over a year.

Good Luck

 

you have to re-jet after K&N? I have a k&n in my xplor and you really have to rejet? why and to what jet setting?

 

I run K&N in everything i drive my old 400 scrambler to my new 400 explorer and eeven 2 500 H.Os I have never rejeted them they run just fine. Maybe i am lucky, NOT. Ask my wife She married bad luck.

 

I would go with the hpd exhaust. I bought my exhaust for the 2000 scrambler 400 adn it bolted right up to my motor. You will have to make your own bracket for the rear but it isn't difficult. I went with the msa spark arrestor from hpd. It is almost as quiet as stock. Get the delta v-force reed cage. If you don't have the extra money just get boyeson carbon fiber reeds. They almost give you the same performace for half the price. Get a k&n filter to help it breathe. Get a new carb. I put a 39mm kehihn pwk carb on mine and it gave me lots more mid to top end power. Get rid of that polaris piston and get a .20 over wiseco. Have your cylinder ported and polished and shave the head. Then get rid of that stock polaris belt and get a goodyear powerstreak belt. They are tougher and last a lot longer. Finally you will have to get a clutch kit. I have a hot seat performance clutch kit on mine and haven't had any wearing or problems with it at all since i bought it a year and half ago. I don't know how well the heel clicker clutch kits do but they sound awesome. Either way you have to be able to get the power to the ground so you need a clutch kit.

2000 xplorer 400, too many mods to list

 

You guys offer good advice.Id like to share some as well.Stay completely away from DYNOPORTS pipe and silencer for the Xplorer.Of course the owner [Rich] will tell you how great his pipe/silencer is and that you dont have to re-jet or install a clutch kit,however,he forgot to tell you that you really dont gain that much over a stock pipe,and the silencer fit is horric at best.His pipe does not meet current DB sound levels either,mine hit in at 99db,5db over the sound limit for Michigan.

Then when you go to return his JUNK,he all a sudden has a ''no return'' policy.This guy is a jerk and could care less about what he sells his customers as long as he sells,BUYER BEWARE!
Bill

 

Bill, did you get your sprockets and chain yet? I would like to know what you think of them. By the way, i am running a 42 tooth rear sprocket. I thought it was a 38 but it says 42 right on the sprocket. So you shouldn't have to worry about the 38 tooth messing up your bike. Let us know how big of a difference it makes.

 

Meangreen,
the sprockets came in yesterday.Im waiting for my NEW primary clutch to get in.I asked my parts guy at Polaris if the 38 tooth sprocket would hurt anything?He checked with Polaris and they said it will work but they dont recommend it.Im going with it anyways.As far as I can figure,it can only make my AWD system engage quicker than normal,thats no biggy.I need a little more low end anyways with them 26 inch Mudrunners.I'll keep you posted,
Bill

 

Muddy & Dazed ~
My reply to you questions and answers are these: In stock form, your 2 stroke is jetted rich from the factory. You'll be able to run it from FL to MI, CA to MA just about any time of the year without it blowing up or blubbering to much. But once you add a pipe(makes it a little leaner), K&N (a little more), winter (a little more). Now with a little luck, you may not seize it. But you won't be getting the most out of your engine either. With this I mean, power, life & mostly proformaence. Now granted it's more important on a 2 stroke than a 4 stroke, but it's still needed on a 4 stroke.
IE: I used to change my jetting on my 400 scram 4 times a year, sometimes more. Seasonal or 30+ degree change. And I never got beat but a same mod scram, along with very little engine problems.
Now my DS I rejet only 2 or so times a year, needle about every 3 or so months.

 

DSLOVER,
Im running a PSI pipe w/stock Scrambler silencer.I have Delta V-Force reeds/spacer kit.I also have a KN Filter.I just had a Heel Clickers Clutch kit installed too.I have RcR airbox mods as well.I just went from a 36 tooth rear sprocket to a 38 tooth rear because im running 26 inch Mudrunners all the way around the beast and I'd like to climb out of the hole a little better.

I did rejet.Currently[summer] im running a 220 main,in the winter [below 40*] I run a 240 mainjet.I have never fouled out a plug and I have 1500 miles on the Xplorer right now.
Bill