Rings break when the end gap is not set properly, because there was not enough clearance. If the factory had some rings that were too tight and your jetting was lean, the ends of the compression ring butted together. When rings butt they loose seal and allow blowby. This unequal pressure on both sides of the ring starts ring flutter and the harmonics cause the ring to fracture into many pieces.

The stock carb is extremely lean in low to mid range. In the early days it was standard to turn the pilot screw out 5 to 6 turns.

 

OMR was saying earlier about ring flutter and harmonics which are related with rpm. Wasn't the 04 x the first with a higher rev limiter? If that was the case, I don't think Rotax would have found that as soon as they did. We know they found it because of the limited models that suffered. The ring end gap sounds most likely but a different vendor of manufacturing or heat treatment could be it. Rotax did have differing ring issues with other motors around that time.

 

To set the record straight on my situation. I am running a stock CDI and ported intake with a full ALBA system. The bike only has a couple hundred hours on it and am paranoid with jetting. 3rd clip and dyno jet 180 at 4750 ft. 190 at sea level and 170 at 6000 plus feet. I rarely run up against the limiter so this seems very odd to me. My 03 DS was run many more hours with the same jetting and mods with no problems! Go figure...

 

Are running with the lid-on or off?
Have you tried any of my mods?
3rd clip from the top down or bottom up?

 

The only one of your mods I did was the shortened air hoses into the air box. I have the box lid open and it is the 3rd from the top clip.

 

no way lean jetting is gonna cause this kind of damage on a 4-stroke stock motor with 9.7:1 compression on gas, you would suffer from such a severe power loss to raise other obvious alarms and questions well before jetting is so lean as to cause this damage - if your bike was running "good" then even if jetting was off it was no way off enough to cause this damage, and any mechanic or dealer who says otherwise needs to go back to school.

sounds to me also like you got one of the bad ones these guys are talking about, 00-06 may all have the same pistons and rings but that doesn't mean there was't a new guy at the rotax plant in 04 that didn't know how to properly set ring gap...IMO either the motor sucked something up through the intake due to failed or poor filter seal or the there was ring failure.

 

I believe my rings are going, its burning oil at a consistent basis, i can smell it when im riding and when im on it hard and get off the gas it smokes slightly. I plan on running it through the summer if it lasts that long[img]i/expressions/face-icon-small-smile.gif[/img] kinda wanna save the rebuild for the winter!!

 

I wouldnt run it anymore.....it can cause ALLLLOT more damage. My jug was completely screwed, my head was bashed to living hell, and some pieces got down in my bottom end. Replace it now and pay 400 or so........ or replace it later and pay thousands.

 

<div class="FTQUOTE"><begin quote>Originally posted by: derrick2v

I believe my rings are going, its burning oil at a consistent basis, i can smell it when im riding and when im on it hard and get off the gas it smokes slightly. I plan on running it through the summer if it lasts that long[img][/img] kinda wanna save the rebuild for the winter!!</end quote></div>

What model year is yours??

I feel for you guys but my stock pistoned 04 has run flawlessly. How many hours are you guys at?

 

Its a 03 Baja, as of the hours im not real sure i bought it used, it was in excellent shape, i kinda knew the guy that owned it he had bought it for his wife and she never rode it, so most the hours are from me i would have to say mabye 60 hours or so?....im just throwing that out there not real sure? Its completly stock, just had the valves adjusted last fall and changed the oil before mem weekend. its weird cause i ran it a few times this winter on the river and lakes and it was fine? The only thing i could think of is that a few times over the winter i used ether to start it cause it was so cold and it was not firing. I know ether is not good for the motor but i never used that much. Ive had the machine for over a year ran awesome last summer and the winter. No maintence accept changing the oil and the valve being adjusted!.