is it from a ski-doo ??? what type of sled does it come ? not sure how u call it but some doo sled have a fuel ritch lean gadget with altitude ..........they seem not to work very good ?????????????????
3g racing
New member
Looks lean to me but I'm no expert
Mach Z 1000 - 2005 with 5,500 miles on it. It's called a Boon Docker and I do not have one.
roudyroy1
Active member
Calling it lean due to the grey looking carbon and large hot spot under the piston. Not hot enough to cause a melt down, but hot enough to cause the piston to swell and seize.
max17ime
New member
If it's a Mach 1000, don't ask yourself why it blew up...
staggs65
Moderator
That's not how we play here. Please keep the comments constructive
max17ime
New member
Sorry, I didn't mean to be negative. It's just important to acknowledge that these machines were known to have issues. At the end of the day, it may help finding the reason for the burn down.
I can roll with the punches. Still need some more opinions on what is going on with the motor.
YooperWoods
New member
Need to do a leak down test, but since you have it torn down that's not possible unless you put it back together. What side piston went or was it both? What's the story on how it seized, were you running the lake, idling in the garage, what happened?
J
jaydougempire
Guest
Black spot underside looks like piston crown got too hot. Cooling issue or jetted lean. Unless scuffs are on intake side tun you have an oil problem. assuming ales is stock. No advanced timing or high comp. Could be too hot spark plug range
J
jaydougempire
Guest
Sorry my spelling is just awesome
A couple of bucks
VIP Member
Which hole and how are the others?
Both sides look the same. I bought it with this issue and ran it for 500 more miles before the pistons started sticking. My guess is detonation caused excessive heat which burnt the oil. Just not sure why the detonation except for incorrect squish, bad/low quality fuel, etc.
roudyroy1
Active member
No detonation marks though??
J
jaydougempire
Guest
Scuffs are Intake side or exhaust side?
J
jaydougempire
Guest
If the entire piston is scuffed that could be piston to cylinder wall clearance issue. Cylinder/piston out of round or out of Max wear spec.
Scuffs just on intake side. Both pistons look the same. Fuel injected SDI 995 motor. Signs of detonation are on the piston pin. Used stock plug. Motor is completely stock but previous owner had a BRP can which I took out. Oil setting set to stock with BRP Synthetic used.
J
jaydougempire
Guest
Ok try replacing the oil injectors on the back of your crank case. I would say there is definetly an oil problem. Everytime I do a skidoo motor I replace these injectors. You'll need to carefully heat the case around the Injector because they are press fit. Replace with green loctite/retaining compound...ive seen a ton of ****ed injectors on skidoo motors if this era. When you get them out try blowing some air through them and you will see what I mean. I would definetly make sure the sled is jetted proper as the pictures lool like a lean problem... and check your cooling system. Definetly check all measurements when doing top end to make sure clearances are ok... Ring gap, piston to cylinder wall etc...only other thing I can suggest with that sled is to send your clutches out for precision ballancing. They were pretty out of wack from factory. My two cents...You can try this its somewhere to start. Hopefully Mr viper will chime in. Good luck!