I have heard all the talk of K&N's better greathing et. Here is my problem

Last winter I had a hard time (over a quarter mile) reaching 55mph. Temp was 45 degrees. The thing was a slug. Had carb cleaned belt check,timing et. Only when we hit temps around 65 degrees did it snap out of it. It runs a strong 62-64 in summer temps. I thought I would try and run it without air box cover and it ran like it did when it was cold outside. A slug.

Should this thing have some richer fuel jets?
Why run a K&N when it just gives it more air? I seem to be lean? I would think I could get whatever jets needed instead of aftermarket huh?

Any ideas? I am dreading the cooler weather cept for then I get the tcats out!!

Time for Polaris to put an engine in that needs no mods to make it go.

 

A K&N AIR filter gives you more air, it doesn't rejet your carb for you.

I'm not shore, but I think the colder it gets the richer you have to jet your carb.

Your Polaris comes from the factory jetted for the STOCK filter not the aftermarket K&N filter.



------------------
Arctic Cat 500, Not your average Kitty, The New King Of the Jungle

 

TomCat..
The K&N filter increases your carburetors ability to consume more air.. Wait.. what I'm trying to say is that your stock Polaris(or ANY other brand) filter is somewhat restrictive... And K&N's whole premise is to "tweak" those precious few extra ponies out of an engine.
Why doesn't Polaris(or ANYBODY else,,, automobiles included) put a K&N out of the factory... SEVERAL REASONS:
Cost (K&N cost more than a factory filter)
Throttle noise.. After installing the K&N you'll notice that you hear the carb. more when you gouge on it.)
Maintenance Chores (not EVERYBODY does their own maintenance, and some wouldnt understand the idea of gently washing and oiling a filter.. I can just see some old farmer pouring Quaker State 10/40 on it, then fussing at the service guy a day later.)
Parts Sales..(If you put a reuseable filter on it from the factory, and its serviced right, how or why would you be able to sell replacement filters every year???)
As for re-jetting, you must have just bought the filter... not the complete kit..(like from Highlifter) I believe that theirs comes with the Jet Kit and the Care Kit..
Colder air temperatures require a righer fuel mixture (air is colder=more dense) If you've installed the K&N, you NEED to re-jet.. Its NOT hard to do, and you WILL like the results..!!
Good Luck!!

 

Hey thanx guys I know about K&N's I run them on my tcats. What I was trying to say was that with my cover off even with warm temps it runs lean like it did in the cold weather. So a K&N with more air flow would naturally run leaner and thus put me back into the slug catagory. Even with the cover installed.

Sleds are 2 stroke this thing is four I thought it wouldn't be so finicky.

So on this four stroke what jets would a guy run with the K&N's.

Thanx for the help. Had no problems jetting my 400 scrambler. 4-strokes are messin with me! Thanx again

Mudmachine? Where would Iorder the complete kit? Even then I bet I would have to go richer in the colder temps? Below 50?

 

Tomcat,
Try www.highlifter.com go to their product catalog, and look up their Power Kit.. It'll have a K&N Filter, Filter Care Kit, a prefilter, And a Dynojet Jet Kit..(I think it comes with a sticker too!!!) its about 115 dollars.. They have LOTS of other parts in different sections for the Scrambler 500. You might be able to just purchase the Dynojet Jet Kit seeing as how you already have the filter... they have a toll free number... just give them a call...

 

Thanx guys for the help and websites. I checked out dynojets website and am gonna call them in the AM. Their jet kits are under 60 bucks. Thanx again

 

When I installed my K&N it felt like it was closer to the right jetting than with stock. When it had the stock filter, from idle (in nuetral or gear), going from nothing to a lot of throttle it would cough, unless I gave a little above idle, then hit it hard. With the K&N it runs a lot better, it only coughed a little a few times when letting off from 3/4 throttle to nothing, and that only happened a few times. With the K&N, I can go from idle to any amount of throttle without it coughing.

I talk to Keith at DynoJet about their jet kits a while back. He said the kit has different sized jets in case you ad a K&N, different, pipe etc... I asked about if you removed the air-box lid or somthing similar. He said they tried doing that, and that it actualy did better (even when re-jetted) with the air-box lid on, but with a K&N. He said on the 400's it was different though.

I tried it without my lid once. What was it like? It was a lot louder from where it's sucking air, it sucks a lot of air! It also didn't run as good. Of course maybe the jetting was off with such a huge difference in air-flow.

I haven't ridden my Scrambler in cold weather yet, but this winter when it gets down to around 70-80 I will ride for sure! :-) I heard with drastic tempature changes, re-jetting is needed. My Scrambler came with a spec-sheet and on the back I think, it had a chart with different clutch & jet setups, showing the mechanic that sets it up what to set the clutch/carb at depending on what temp/altitude. I would check that out, if you don't have it, if I can find it, I can scan it for you.

Good luck!

Adam Dowden

PS-Everyone should a K&N if they have a Polaris, I waited to long!

 

Adam, I was messing around today and found that the K&N off of my tcats fit perfect. I tried it out with the stock pre-filter and it seemed to pick up about 9 tenths of a mile per hour. (radar) If you can scan that page and mail it to me (rtic@aol.com) it would be great. I will have to do some more runs to see if there was an improvement or just a better start. So far the K&N seems to give it a tad more. I also found the stock paper filter broken around the clamp. What a cheap filter. I can see how the K&N will work much better that stock. I am going to have to find someone around that runs the 500's in the cool weather 50 and below. Same type of thing with the lid off on mine too! Sounded like it was gonna suck ol mr. Nad right through the seat. lol. I am gonna run some longer pulls this week. Thanx for the response. Always learning with these 4 strokes. I dread the day if it ever happens that they take my 2-stroker snowmobile away!! I would love to see my 200+ HP Tcat engine sitting into the scrambler chassis! Yee haaaaa!

 

Try adding a stip of duct tape to your air filter, this should richen the fuel mixture if this works and your power band comes back your running to lean.

 

maybe a stupid question but I have a sportsman 500 with a K&N filter, am I going to need the carb jet kit this winter? Just wondering before the snow starts.