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Discussion Starter · #1 ·
I had the new ceramic chrome rings put in my 03 800X 150 miles ago and my compression is only 140 psi! I am kinda disappointed because I was hoping for something in the 150 to 155 psi range. Both cylinders are exactly 140 psi and I am confident that my compression gauge is accurate. These readings are on a hot motor with the throttle closed and the plugs out of both cylinders. I tried it while holding the throttle open and it did not seem to make a difference. I have the 6 hole base gasket and my squish is .073" (73/1000ths). What do you guys think?

1. Is it realistic to expect 150 to 155 psi with an 03 800?

2. Do these new ceramic-chrome rings take longer than 150 miles to break in?

3. Any other reasons that my compression could be low?
 

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who cares what the number is if the sled is running great? It is good to keep an eye on it but you'll sit there and worry yourself to death....Just ride it! I am getting my 03 800 back tomorrow with the new chrome nitrate rings or whatever they are. Your not experiencing poor performance are you?
 

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Discussion Starter · #5 ·
Flipmode,

I am unsure about the glaze. The work was done by a reputable Ski-Doo dealer. I would like to think they did it correctly but you never know. FYI, the engine was not running bad I just noticed the flaking starting when I pulled a RAVE valve. The Mag side did not have any flaking and the PTO side only had what was visible through the RAVE hole. The sled had 2200 miles and the pistons looked excellent so they only did the rings. Also, the rings they used are the 04 race/05 stock rings. I was told they were ceramic/chrome but I think the correct description is what Skidoo'sbest said - chrome nitrate.

Skidoo'sbest,
No notable performance problems but I am not sure what will happen when I line up with another 800. You are right that I should just ride it but I like to squeeze as much performance out of it as possible. I don't race much but I do like to play around with other sleds on the lake now and then.

C-money,
When people post compression readings on here are they usually on cold engines? I always thought it was best to check compression on hot engines.

Also, I probably didn't help with ring seating. For one the dealer obviously loaded it up with assembly lube as it smoked like crazy. I added a half quart of Doo mineral oil to the first tank and I run Klotz Techniplate synthetic.
 

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Test the compression Cold. However IMO its unrealistic to expect 150-155. Yes there are freak sleds that have over 140 in stock form but theyre more of the exception in my experience. 140 psi is normal and perfectly acceptable, enjoy your sled.
 

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Just for an example. I put cudney rings in my 600's this season. I only have little less than 200 miles on each sled and all 4 cylinders read 135-137 on my guage (cold with no throttle). The way they run makes me smile.
 

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I was told the 03 non HO 800 should be around 140 psi. The 04-05 HO 800's are closer to 150. Not sure if its true but it seems to makes sense.
 

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I dont know about the 800's but get this. My 440 with LC domes reads 150/ side cold and 130 after completly warmed up. I would not be afraid of your readings on a warm or hot motor!
 

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chrome rings take longer to seat then moly rings, 150 miles ain't much, check again after 300 miles and I bet it'll be higher.
 

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I got mine back after being reringed and I had 150 per side. I have now ridden it 300+ miles and am going to check again.
 

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I have an 03 800 sport, ive had 150# of compression since i bought it .
It had 600 miles when I got It, now has 3054 miles.
It still has 150# just checked It tonight.
guess Im pretty lucky!!
 
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