I've been following this forum for a little while now and have found out much from the feedback. I am looking to improve the performance on my 2000 500 Sportsman. I love the automatic tranny and the awesome ride, but would like better overall acceleration and speed of course. Have looked at the sites by Highlifter and others, and was wondering if anyone out there has installed a performance upgrade on there Sportsman? Your feedback would be very helpful!

 

I added a KN filter,a HP clutch kit.No real noticeable gains.My top end is at 57mph.Are you [69cobra] saying your top end is only 50mph?Thats not right at all for a 500cc Sportsman.Mine is also equipped with 26 inch Mudrunners to.Your right about the pipe.I talked to a guy at my local riding area,he said he noticed very little differance with the pipe.Im betting the 40mm carb is going to make noticable gains though.====BILL

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It sounds like what is needed is a camshaft replacement. Is the Sportsman camshaft different than the cam in the Scrambler HO?
(I assume it is due to the differences in weight and intended purposes.) So... If it is has anybody initiated the swap yet?

Usually just adding a larger carb will decrease fuel mileage, rob low end torque and deliver no more top end unless the engine was deliberately undercarburated to begin with.

How about it parts managers? Does the HO Scrambler sport a different cam number?

 

My cousin purchased a 99sp500 6 mos. after me. Of course we had to race 'em. He beat me every way possible. In 2wd, high and low. In 4wd, high and low. Oh, to get back at him!

 

Hi SWAC Im also interested in improving the performance on my 99SP500. So far from what I can see there are not many choices. Pipe doesnt seem to offer much gain in performance. Roller cluches are supposed to work well. Im waiting to see how Jack Schultz makes out on trying a 40mm carb. So far that seems to be the best shot. Im looking for more top end, bottom and midrange are fine. My Sp falls on its face at about 40mph takes a week to get to 48mph on hard flat road. In the woods it has more than enough power but would be nice to hit 50 with no problem!

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99 Sportsman 500,00 Trailboss 325

 

Okay Foster, just what did HE do to his Sportsman to make it better than yours?

 

Ok here's the secret, upgrade your carb! I put a 39mm carb and hi flow air intake from the airbox to the carb with a K&N. With just that mod I could bury the speedometer at 60mph where the needle wouldn't move anymore and then it would keep on going! I never did get it clocked or wide open so I can't tell ya truely how fast it is. I bought the whole kit from Four Stroke Tech in PA but I can't find their number. I know AAEN Performance has carb kits (414)552-8981 so you could check with them. The kit I got was featured in I think in a fall issue of DirtWheels in 97 it was the FST Sportsman 500. If you want it to fly than get a carb kit, roller clutch, new muffler, K&N, maybe add an aggressive clutch kit, then you could add some extras like a 2000lb Warn winch with bumper, larger better tires maybe the new Titan 583s, more lights, diamond plate cv boot guards, cigerette lighter adapter air compressor w/tire plugs, small radio for breaks and a GPS to find your way around all of the trails. You might even want stiffer springs for the added front end weight of the winch and bumper. There you have it, one sweet Sportsman 500 custom designed by me!

Anymore Questions just ask,

Steve

 

So are we saying that the Sportsman 500 engine is under-carbed? Not having a spec. sheet in front of me. (the office has the Polaris website Net Nannied) I believe that the Scrambler HO has a larger carb. But does the Scrambler HO have a different cam number too? That would be the key to the question.

 

Thor,
Somebody was talking about transplanting an H.O. cam into a Sportsman about 3 weeks ago on here... He had ordered the camshaft and was intent on doing the swap... I don't know if he's tried it yet, or if the head designs ended up being different. (port design, valve size, piston design)
I would just make sure that with the extra lift, you don't end up with a piston to valve clearance problem.
You might look into the exhaust port design, just to make sure you don't end with more of a fuel charge that you can efficiently get ride of,(out the exhaust port...past the valve)
Oh, If you are going to make this camshaft swap.. Remember that the H.O. Camshaft probably has it power in a different RPM range than the Sportsman.. So initial clutch engagement RPM will more than likely have to be changed..
I wonder if WEB camshafts can regrind the stock camshaft with a more "low end torque" profile for moving these 650 lb.+ machines.. Thats what I'm after.. more low end torque. I'm worried that if I were to go after more mid-range and top end on my Magnum 500.. the H.O. camshaft would sacrifice some low end torque..
I guess its a "give and get" kinda thing...

[This message has been edited by mudmachine (edited 01-15-2000).]

 

Any new SP500 I've been around or ridden that has EBS is plauged with the same problem. They are lucky to get to 50mph on the electronic speed. Those with older mechanical speedos are generall getting wild speedo readings that are incorrect. Those that say they can might have speedo error, since they calculate this at 15% variance on any atv or bike. Don't believe the speedo.

I'll have the 40mm carb on the SP500 by next week and will report back if it works or not. I'm very happy with low end up to about 35 mph when it shifts out and hits the wall and takes a week to get to 50. Our 300 4x4 can run around it on top end.

<A HREF="http://www.godigital-design.com/96Polaris.html">Schultz Motorsports</A>