Bad news!
If you saw my previous post...The oil blowing out of the crank overflow was caused by the disintegration of the cylinder and rings due to detonation. The cylinder started coming apart in chunks and eventually the top ring broke into pieces and smashed around in there until they exited the exhaust. I thought this might be caused by the oil can filter being plugged, which I cleaned in recent oil change but my mechanic doesn't think that. He believes it was either jetted too lean or running regular gas or both. I highly doubt that, as it is my 2nd DS and I ran it the same jetting and gas as my previous one which had no problems. I am alos constantly changing jets for elevation. A friend said it might be the needle is too low and if you ride mid revs maybe this is the cause?
Another opinion I recieved from Ron Woods is that the rev limiter cutting in can cause this detonation and damage but I rarely hit the rev limiter. Any other ideas? I cannot afford to go through this again and would hate to have another member have this happen!

Lesson 1: Always use premium gas and/or octane boost.
Lesson 2: Run jetting on the edge of fat when duning.
Lesson 3: Raise needle to ensure midrange is fat enough
Lesson 4: Check and clean the oil can filter every oil change.


Let's keep this post at the top by adding new lessons so everyone can benefit from my misfortune!

Cammer

 

Bummer....Stock piston/compression?? If so, octane is most likely not your problem. Ive been running 87 for a few years now on my stock top end DS with no signs of detonation.

Where is your needle set and what jets are you running? Were you getting any popping out of the exhaust on deceleration? Sign of being lean.

I have a stock piston with very low hours in my garage. Let me know if your interested......

 

I see you have an 04 x. Mine is the same and I had the same problem. I posted on it a while back. My ring had broke in many small peices and started to overlap in the groove. Then a chunk from the ring groove to the top of the piston broke and I lost power. I discovered all of this after dissasembly. I think your ring broke first then caused everything else. Mine was NOT caused by deto. There were no deto marks on the top of the piston.

Another note: Since new, my oil would be black very shortly after changing (another past post) about a year later our problem happened. I had bought a stock '00 motor from e-bay that I planned on building big. It was hammered but I didn't care because I was building it. Well, before I got to that project, my 04 failed. So I put in the e-bay special. This thing was so much faster than my 04 motor that I asked if the 04's had different cams or timing or something. Plus it was hammered and probably tired. The point is, I think my motor was junk from day one. Especially looking at how long it would take for my ring to "machine" out the ring groove like it did.

 

Welcome to the club of bad ds motors....We had a major topic going a long time back about this......very interesting.

http://forums.atvconnection.co...464772&highlight_key=y

 

That is a good post. Mine is a 8-03 7995 model also. Did anyone find out what Rotax did to make these rings fail? I'm used to car stealerships telling me I'm the only one who's ever had this happen. So I never talked to my Bomb stealer.

 

If i remember right bombardier only admited it was there fault one time....and that was to my local dealer and thats why i got the only warrenty out of the group of bad motors. They never said why they failed just that it was a factory error or such. Once you fix it and get her broke in good....i think you will be very surprised at how good she moves. I am pretty sure i ran with my top ring broke for along time without noticing it or any power loss.

 

2000 thru 2006 same piston & rings,don't blame Rotax!!!I have only seen 2 out of about 200 motors that this has happened too,both had aftermarket CDI and ran 87 fuel.READ YOUR OWNERS MANUAL!!!

 

I thought Cammer was running stock CDI??? I saw no mention of aftermarket...

 

Mine was completly stock at the time. Not even an endcap. I bought it to gas and go. (That didn't last long apparently.)

 

<div class="FTQUOTE"><begin quote>Originally posted by: Boomer84

2000 thru 2006 same piston & rings,don't blame Rotax!!!I have only seen 2 out of about 200 motors that this has happened too,both had aftermarket CDI and ran 87 fuel.READ YOUR OWNERS MANUAL!!!</end quote></div>


Boomer....not to start anything but maybe you should read the thread i listed above. Bombardier did infact say it was there error....since they paid for my repair even though my warrenty was OVER. There are 6 cases listed in the post above of this happening to well maintained STOCK motors ran on 91 octane fuel. It is infact bombardiers "fatal" flaw if you will call it. It is a VERY RARE case it seems but it is out there.