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Discussion Starter #1
anyone who has an mxzx700 might have a big problem i noticed  when i first got my sled that the right cylinder is leaning out in the mid range i thought my dealer might have done the recall wrong so i had another dealer look at it and check the recall update to make sure it was done correct it was done right and the sled was still running lean in the mid range i have a digitron system which tells me my exhaust gas temps and they are climbing above 1250 degrees in the mids on the right side  it only hits 1120 on the left and holds about there at wide open it is ok it drops back down to a safe level around 1150 or so i thought it might be my sled only but the guy at the dealer shop is a friend and called me today and said he just got another sled in that burned up the right cylinder i brunned mine up a few weeks ago since then a few of these sleds have been in for right side cylinder burn up i dont know what i am going to do yet but the repair guy at the shop is going to mill down my needle in the mid range part of it to richen the cylinder hopefully this fixes it skidoo has said nothing to anyone i wonder if they even know about it and if they care about also i hope anyone with this sled is carefull do not run it in the mid range to long you will probably burn up the motor i have seen 4 engines personally with a right cylinder burn out so far i suspect there will be more
 
 
 

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It doesn't make sense to me that one side could be
hotter than the other. Yes, I understand with the
rotary valve why one side is hotter, but not with these
engines.

I did have one side running hotter, but it was because
of a kink in the vent hose from the airbox to the carbs.
I took that off and also cleaned the carbs and everything
seems to be in line now.

I've often thought that all vent lines (DPM or non DPM)
should be exactly the same length to give the same
results across the cylinders.

I'm curious with other's experiences.
 

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My '01 800  twin has extremely high mid range temps in the exhaust according to my digitrons. Around 50-60 mph the temps at a steady throttle will climd as high as 1400 degrees.
Full throttle temps are good around 1190 to 1200.
Couple weekends ago I held it at 60 mph for about 2 miles and nothing happened. I thought I heard some people talking about it giving a false exhaust temperature reading on the 800 twin. To me its seems that you can't get a false reading cause its just a temp probe right? if it reads off it will read off at any temp not just at one particular temp, but thats what I heard earlier in the year. I think it might have been on snowest.com though, not sure.
josh
 

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Yep, it's good to see others with EGT's. I have been seeing the same thing with my 800x2002. The mag side will climb to temps that are very concerning. I pulled the plugs many times at 7000rpm after a long run and they are in the danger area. The mag side is the worst. The needles are not adjustable on the 2002 800's.  
I heard the same thing that your gauges are off. I don't really care what the temp reads beacuse I read the plugs/piston wash and then reference the gauge. When there is a 200degree difference bewteen WOT and the midrange, there is a problem and it is a lean spot, mag side being the worst.
I added an extra washer under the needle to lower the temps but it still has a lean spot at 7000rpm. I have talked with the dealer and Ski-Doo and they admit there is a problem but still don't have a fix. I have run down to -20F already but never hold it at 7000rpm very long. I seen a drop of 100 degrees after adding the washers but it makes the sled very rich from 5000 to 6500rpm. Current setup is 500's mains and .036 extra washer under the needles. I have tried 3 different settings on the fuel screws. It's safe but the milage has suffered slightly and the after a hard run for 1 mile or so, I have a flame thrower for about 3 to 4 minutes after the run.

I brought the carbs to the dealer and we verified that the needle jets were pressed to the proper position per the Ski-Doo bulletin. My dealer has been helpful and has called Ski-Doo several times while I was there. Hopefully there is a fix soon! And yes the sled is out of breakin, I have just under 1000 miles on it!!!!!!

MidMich800twin and doodoo let me know if you made any changes to the fuel system and if you had any good results!!!
 

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I realize that  it is importantto keep moter stock

But.  
I highly recomend sending pistons to swain tec for ceramic coating

I realize that stock pistons come whith a coating on them but  in my
opinion the swain tec coating is far supirior.


whith swaintec coating and ams oil   it is allmost  imposible to burn
down a piston.........
 

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Discussion Starter #9
the needles are not adjustable i put a washer under my needle also to raise it i had the probes tested they are super accurate they are also placed in the correct spot a motor should melt down at 1380 degrees i am going to shave a thousandth off of my needle in mid range i will let you know how it goes
 

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Nothing new guys, The MachZ,s have always had a 6000-7000 rpm lean area. I always thought it was something to doo with the rave valves opening. Dino.
 

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Has anyone had or heard of this problem with any of the 600s.  Will the dealer repair the engine at their cost since it seems to be a product failure or are they trying to say that it is not their fault?
 

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Discussion Starter #12
they fixed my seld at no cost but it is still under warranty i heard as soon as it is out of warranty that they will not cover it
 

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I installed the probes as to the skidoo racing hand book with two probes for the single pipe. 1 cylinder is atleast 100 degrees hotter for whatever reason. Rode a couple weekends ago and held it @ 68-7000 rpms for about 2 miles figuring that if it went it would go and it never did. Not sure why it will pull 1400 degrees and not burn down, skidoo must know what they are doing I guess.
 

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My God I spend to much time at this computer !
Do you guy's and Gal's have Dpm's on your machines ?
Have you had the main jet updates that includes RAVE, oil pump cable adjustments and reprograming the MPEM.
I just seen a post on Snowest about Polaris 800's having a lean spot up to 1400 degrees (still running) so I guess it's not just a Ski-Doo problem,Polaris and Ski-Doo "USE THE SAME PISTON COMPANY"
Polaris uses the standard 5 position e clips jet needles too !!!
Better mpg mean less gas, less gas means hotter cylinders and yet if something happens with the engine its the oil fault if you use a different brand than OEM !!!!! YEAH RIGHT.
 
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