will the pistons and rings fit from 04 into the 02 what changes did they make to them if any.???or should i go with the weisco double ring setup.? and i was going to get the pistons coated .do u think that will help with the midrange heat build up. SWRules :thumbsup: :D

In my opinion, just changing out the pistons for a double ring unit will not take care of our lean mid-range problem.

There are several contributing factors to the problem of the rings getting taken out by heat. Combustion chamber design, carburetor design (or lack thereof), timing curve (which has been made nearly impossible for a guy with no connections to get changed), and the make-up of the ring itself.

The best advice I can give anyone right now is: If you want to just keep the 800 in the shape it was new, put in a new set of pistons and rings, shim up the needles by about .010", adjust the fuel screw to compensate, and ride it.

Try to not hold the throttle near the half throttle postion for extended periods.

There are a lot of fixes out there and some of them do help a great deal. Just keep in mind that all of the problem areas mentioned above need to be addressed either directly or indirectly to effectively cure our 'series 3' problem.

We've tried several different things so far and we're still searching for the low cost, keep you up and running, cure-all for this engine. I have parts all over the shop(not a sled shop) and my desk right now with different things we're trying. Guess I'm hoping to become one with the parts by looking at them for a few weeks. :D If we come up with something reliable, you'll see it here first. If anyone has something they have tried and it worked for you, let us know.

Let's get these 800's up and running reliably while maintaining peak HP numbers for more than 500 miles.

I for one have been running 2 ring wisecos, and am quite happy. They took almost the full season to take a seat (hard rings) but once they did, I had much better luck than I had with the stock pistons.

Now, I only wish I had moly coated the skirts and maybe the domes just for some insurance, to make them more to the OEM piston specs.

As with ANY piston you install, check for clearances and make sure you are at least MINIMAL to their spec for clearance.

What I noticed is more consistant power. I think under hot conditions they seal better on top end.

I think you're probably right about the better seal. I guess all I was getting at was for the average sledder, staying with the stock piston kit there are no new things to worry about such as the different rate of expansion with the Wiseco's. Other than that, I'm with you all the way.

As long as proper piston to cylinder clearance is maintained, there should be no issues with scuffing running a Wiseco. They are made to drop into a stock engine, but there are tolerances to consider.

Wiseco will tell ya that any piston will take a "set" in the first 100 miles or so. They will expand and contract more in that 100 miles than they will the life of the piston. Just proper warm up. I have a digital temp gauge on my Digatron for water temp, and I can see when the T stat opens. The temps climb to 100deg or so, then they drop for a minute, then it starts to climb. Upon 110 deg, I'm ready to ride. I just start the sled, then put my helmet and gloves on, once over the sled and by then Im ready to ride.

I just think that the OEM pistons with the moly coat helps with cooling and durability. Yea, the oil is supposed to take the load, but Elko went to moly for a reason.

I'm not at all saying you are wrong Dave. I don't think you should be saying "no issues" about running a Wiseco.

The term "proper warm-up" being key here. You need to warm up any engine before tromping on it. How many times have you been at a drop lot and been setting there shootin' the breeze and in rolls a truckload. They put on their gear, open the trailer doors, fire 'em, roll 'em out, and the doors are closed and they are gone before the smoke in the trailer clears. That can sieze any piston, but is more likely to sieze a Wiseco. At 50 miles or 1050 miles.

Don't get me wrong, I think Wiseco is a great piston. I ran Wiseco's in my drag sled for years with no problems. They were warmed up though. I did have 300' siezures , but we were running a little tighter.

Now the moly coat from what I have read is more for break-in safety than anything else. Most of the coating located in the areas where scuffing is a problem is worn off in the first 800 miles and does no good after that. Feel free to correct me if I'm wrong.

I was just working toward most reliable more than best running, longest lasting.

what is the price of wiseco ring/s compared to the doo ones? not a question. i run the two ring wiseco's as well. i love my doo, but depending on the rideing you do, you will need to re-ring sometime with the stock series three rings. for most people they are fine, but i am kinda hard on my stuff. :D

Good point! No matter what pistons you run, you will have to re-ring sooner than normal in the seriesIII unless you change some other things at the same time.

Just measured ring end gap and piston/wall clearance. Way out to lunch, so I sent them to my dealer, so far I'm getting new rings on warranty, no answer for the pistons yet. There are new rings available, he tells me that they are chrome coated, is that good? ???
oh ya, he told me that there are no changes for pistons in the 04's :cussing:

The new rings will be better than what we had. They should give you new pistons too. Good luck!

I am using a modified set of Art Pro-X pistons in my 800 doo. These pistons are dual ring and had to be remachined to work in the doo motor. The verdict is not out on the longevity of these yet due to only having around 350 miles on them.

I have the ART pistons as well. I put 900 miles on them last season. The compresson is 152/152. The compression was 150/150 new. I looked at the rings through the RAVE valve ports and they look good. This is kind of subjective since it is so hard to see down the ports.

Those ART pistons, are they the RKT piston mod? I'm still having a hard time deciding on Wiesco or RKT. I think I'm leaning towards Wiesco.

The Arts are from the RKT kit. I am not sure yet about the pistons. They have worked OK (no burn downs) for me but, with so few miles and some other problems I had, I personaly cant yet say if they are the way to go. As soon as the snow flys and I get some more seat time I will be able to say yea or nea.
I have a 02 MXZ 800 and I have had some other issues to work out. Dunkmaster has an 01 and they seem to be working great for him and may work as good for the 03's and up 800's.


Brian

Anyone have the piston kit part # for the '04 800's? Any snocrossers have the part #? Pistons are rumored to be lighter and have the updated ring. Same ring as last years Snow X, but different piston....again.

Here is a picture of the ART piston after RK Tek modified it. You are looking at the intake side of the piston. So far I haven't had any issues. I put 900 miles on the pistons, heads, and porting kit from RK Tek. I am still fine tuning everything but I am getting closer. :D

I also installed them on a buddy's 02 800. I can't report on any results since we ran out of winter before we got the sled back together. ???

I dont know what the ART piston looked like stock, so what were the mods done to it.

hey Dunkmaster, i have a 01 800 mxz with about 3000 miles on it and i was talking to Idooski a while back about freshing the motor.are the ART pistons suppose to last longer ,make more power,seal better,what are the advantages compared to the stock pistons

As you look at the picture I posted earlier, you can see that Kelsey took off some material from the dome of the piston. I also believe that he trimmed a little off the skirt of the piston as well. The ART piston was Kelsey's solution to 2 problems with the OEM piston. The first problem is the OEM ring that will flake off the chrome moly coating. The second is that the skirts on the OEM piston will begin to collapse over time, form cracks, and eventually fail. The twin ring design is to improve the longevity of the rings. The OEM ring cannot transfer the heat away from the piston dome fast enough causing the chrome moly to come off. The twin ring design is supposed to allow the appropriate heat transfer. Anyway, that is what I have read elsewhere.

I pulled my OEM pistons on my 01 800 after 725 miles. These were the updated pistons. The new OEM updated pistons were installed when I bought the sled. I didn't see any evidence of the skirts failing but the chrome moly on my rings was just beginning to come off.

You can make some more power with these pistons if you have Kelsey couple the pistons with his heads and porting work. I have all his mods and I am pretty happy so far!

Originally posted by z24bb@Jul 24 2003, 07:14 AM
hey Dunkmaster, i have a 01 800 mxz with about 3000 miles on it and i was talking to Idooski a while back about freshing the motor.are the ART pistons suppose to last longer ,make more power,seal better,what are the advantages compared to the stock pistons
The Wiseco will also provide you with the same solution.

A note on the ART piston, since the crown has been reshaped, it can only be used with special domes that RK Tech make to work with the pistons. Run those pistons in a stock engine, and you will have serious detonation problems and more than likely do serious damage.

So if one is destoned to use the ART pistons, you have to switch the pistons, head, and add a shim to get to RK Tech specs. Then you have to recalibrate the setup with jetting. You are looking at over $500 and whatever time to get the jetting dialed in. If you are looking for a replacement piston without switching all of this over, the Wiseco is made to drop right in.

I just got the new pistons and rings for my 03 800 and I was told that the pistons are the same as last year but the rings are new. Sorry I don't have a part #. This went on warranty so my dealer took care of it.
the new pistons are not much tighter than the old ones but at least within the wear limits.

800MXZ is right on the money. This is not a direct OEM replacement. I wanted a little extra so I went with all of Kelsey's mods for the 800. I'm getting around 150 hp with mileage of around 15-16 mpg. I'm very happy so far with these changes. I love to tweak so I'm still dialing all these changes in. We just need a lot more winter to play. It takes a real close look to see that it isn't stock! :D

idooski,

The '04 part # I've seen is 420 815 218 (revised 07-30-03).

SummitAK

Originally posted by Dunkmaster@Jul 23 2003, 10:44 PM
Here is a picture of the ART piston after RK Tek modified it. You are looking at the intake side of the piston. So far I haven't had any issues. I put 900 miles on the pistons, heads, and porting kit from RK Tek. I am still fine tuning everything but I am getting closer. :D

I also installed them on a buddy's 02 800. I can't report on any results since we ran out of winter before we got the sled back together. ???
Just wondering? Whats the deal with the hole on the intake side of piston? What does that accomplish?

Thanks
Todd
:)

Originally posted by SDRENE800RER+Aug 17 2003, 04:24 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (SDRENE800RER @ Aug 17 2003, 04:24 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-Dunkmaster@Jul 23 2003, 10:44 PM
Here is a picture of the ART piston after RK Tek modified it.* You are looking at the intake side of the piston. So far I haven&#39;t had any issues. I put 900 miles on the pistons, heads, and porting kit from RK Tek. I am still fine tuning everything but I am getting closer.* :D

I also installed them on a buddy&#39;s 02 800. I can&#39;t report on any results since we ran out of winter before we got the sled back together.* ???
Just wondering? Whats the deal with the hole on the intake side of piston? What does that accomplish?

Thanks
Todd
:) [/b][/quote]
On the power stroke the piston is compressing the crankcase. As the holes opens to the intake port, the gasses in the case are pushed through the hole. In doing that the mixture from the case is cooling the wrist pin and the underside of the dome on it&#39;s way to the hole.

So this is done for cooling purposes and not for performance?

Thanks
Todd

Originally posted by SDRENE800RER@Aug 18 2003, 05:09 PM
So this is done for cooling purposes and not for performance?

Thanks
Todd
Depends on how you look at it. There is a minimal amount of direct gain, but there is more indirect gain in performance. Heat kills! Better cooling equals better performance and longer engine life.

Originally posted by idooski+Aug 19 2003, 01:13 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (idooski @ Aug 19 2003, 01:13 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-SDRENE800RER@Aug 18 2003, 05:09 PM
So this is done for cooling purposes and not for performance?

Thanks
Todd
Depends on how you look at it. There is a minimal amount of direct gain, but there is more indirect gain in performance. Heat kills! Better cooling equals better performance and longer engine life. [/b][/quote]
Okay, I can see that point, everything in the right direction helps at the end. It makes me wonder if that hole would let the piston travel on its downstroke with less effort by giving the trapped pressure somewhere to go?

Thanks
Todd
:)

EDIT...I get to see them up close and personal...I just placed my an order with RKT for the whole 800 package....pray for lots of snow now

I have looked at all the options and Kelsey at RKT knows this engine the best and has the best set up. His 827 kit rocks and is very very reliable. Call him up

I now have 2,000 miles on Kelsey&#39;s ART pistons. I still have 150 lbs compression on both cylinders. I removed the Y-pipe and looked at the rings. They look real good. No pitting...what a concept!! I&#39;m still playing around with the timing trying to find the "sweet spot".

:cool:

are these ART piston kits dunkmaster and others are talking about for stock bore...ie NOT the 827 kit?

Yes.. This is for the stock bore 800 not Kelsey&#39;s 827 kit.

anyone have a price on porting pistons and head? why isnt this on the website? is he not selling the stock bore pistons anymore becuase he has the 827 now?

i have the wiseco 2 ring pistons in my motor now had them ceramic coated on top and teflon on the sides ..2000 miles on these and no problems ..you need to let them warm up .....i see cudney racing has a piston kit for stock 800 give bill a call ........www.cudneyracing.com