3TV,

Thanks for the update. I have been enjoying the posts of your quest for the ultimate Scrambler. A shame the airbox mod didn't pan out. Fear not....this too shall pass. It is threads like these that remind what a great resource this forum can be. I almost forget about all of the Trolls lurking about.....ALMOST! LOL

Here is my question. Getting more air to the motor isn't helping then how about restricting airflow a bit? Sounds silly but the reason I ask is I am contemplating snorkeling my bike. We have lots of water and mud down here in Texas and I already have my PVT snorkeled. I recall Gregsims snorkeling his Sportsman and he said that a smaller diameter snorkel size yielded better performance on his bike. Could this airflow restriction cause the carb to give the motor more gas (resulting hopefully in a faster speed) or is my half/@ss knowledge of 4 stroke engines just confusing the issue? I realize a snorkel may not make sense for you in your climate (desert and such) but wonder if this may help you get closer to where you want to be.

Regards,

MrMan

 

My son's EXP 425 finally took off with the addition of a Mikuni 38 mm flatslide carb. It is now dead even with my H.O. in a 100 yard drag race, with him aboard. The H.O. cam and muffler porting, which I have figured out, didn't do anything till the CV carb,
a Mikuni in this case, was replaced with the flatslide. We havn't modified the airbox because it has a pretty large airhorn stock.
The H.O. despite a AAen full duration cam and airbox experiments and muffler mods is still the same. I just returned a Mikuni TM 42mm -6 pumper.
An awesome looking carb, the throttle cable holder won't clear the gas tank. I am awaiting a new Mikuni TM 40mm that the guys from Carb Parts Warehouse think will work.
In the case of the H.O. Sportsman, nothing will improve performance, which is only 1% better than a stock 2000 Sportsman, as long as that CV carb is on. And all of these carbs have had vacuum ports for the fuel pump. The TM 38 came from AAEN with a special top mount for the throttle cable and a vacuum fitting.
The Limiter on the EXP is what is holding it back now. I read the post on disconnecting the Scrambler limiter but couldn't find the same colored wires on the EXP. Any help here would be appreciated. You can be sure I will post when I get the H.O. tricked out.

Silly Later,,,Fourlix

 

Did you look at the wires that come from your override button Fourlix there should be a grey wire with an orange stripe follow it and unplug it it should come to a female connection some where if you do have have the same colored wires there should be one that comes from the button that ends up at a female recepticle somewhere if so unplug it and try it out it really cannot hurt anything if it is not the right one just don't go cutting anything .......lol

Good luck

 

If any one does not beleive that airbox mods will work an a Scrambler 500 will not work then they need to call HPD. We have a 2001 Scrambler 500 in our group with HPD's airbox kit, carb kit, exhaust and clutch kit. This bike kicks ***. Like I have said all along airbox mods do not work without other mods to compliment them. The engine is just an air pump. It does not do anygood to get more air in if the motor cannot get more out. I have seen plenty of bike with airbox mods that work great. The CV carb is not something new to Polaris, it has been around for a long time. Street bikes run these carbs and they run with K&N filters bolted directly on the carb.

Fourlix,
So far I cannot find any information on a rev limiter on the Xpedition. I think one reason why we all have different top speeds is the speedo itself. Last weekend my speedo would only show 40 mph but I had fifth wound out real tight. I am thinking about trying the CDI box off of Scrambler 500. These bikes rev higher because of the HO cam. I have been told by some Polaris mechanics that the bikes do not have rev limiters. If they do have one then it is very different then anyone I have ever heard. Most rev limiters let you know when they kick in. Polaris motors just seem to flatten out when revved high. I think that the CDI box just starts retarding the timing and the motor just flattens out. Gonna try the HO CDI box and see what happens. Gotta get a tach of some kind first so I can see how high the motor revs.

 

You're right...I never could tell who won the races, I just went by the end result. Also, I never did ride your quad. I stand corrected.

That's where I noticed the most improvement on my quad too; mid and low range power. Let me know if you're going to want to try the K&N. Worth a shot anyway. Went to the desert today, huh?? I'm jealous. Looking out the window right now it looks like we're in for a nice little snow fall. 400 may have to take a back seat to the 335 next time. Thanks again 3TV.

 

Shaggy, I see you are running 589's on your Sportsman. I am getting ready to get 26" 589's (kit from Rocky MT on ITP wheels) or 26" Mud Runners on the stock rims. How do the 589's feel on different surfaces? Is there a big differance in ride from the stock tires?

Thanks for any info....

Mark

 

I am having great difficulty believing that air-box mods won't help performance on a modified 500. I cut approximately 2"x8" strips out of the sides of my airbox and drilled about 10 1/2" holes in the top and saw a noticeable increase in mid-range acceleration. This is with a K&N, dynojet kit, IDS2 with all discs in and a 165 main jet. I don't pretend to be an expert on the 40mm carb, but in my mind if you jet rich and have a pipe that can move exhaust out quickly, bringing in more air has to make an improvement.

 

Hellooooooo, Kevin.

I rode with a fellow last weekend who had the HPD clutch kit, pipe, muffler, and carb mods on a 2000 Scrambler. He ran out of gas two times with 41 miles on the odometer. That figures out to about 11.4 MPG. What type of mileage do you get?

To add insult to injury in a lake race he was beaten by a 325# guy on a 2001 HO with no mods.

No flames intended here, but it sure didn't seem to be the way to go. He couldn't take off without roosting snow all over anybody following him and he didn't have any top end. What are the tuning secrets with the kit your friend has?

 

I've ran out of gas once in the last year and I have no doubt that I can reach 70+ on top. The key is trial and error and common sense. I've experimented with the number of discs in the muffler, different springs, different weights, different carb jets, airbox mods and roller clutch settings. I've got it pretty much where I want it now. I gave up some bottom end (the 500 can spare it) to gain some mid and top-end and I compensated by smaller tires and a more radical clutch setup. I have surprised quite a few people with what a 540lb 4x4 will do.

 

3TV,

If you are interested in the mods that are on the bike just call HPD. All of the stuff on this bike came from them.