Anyone have any ideas as to what might have caused this? MAG side piston/cylinder from a 900 fusion.
Piston/cylinder woes
- Thread starter sloan188
- Start date
whoops...here are the pictures...
Symptoms if anyone is interested are: 3-4 pulls to start, low idle first couple of times you start it (sometimes stalls), high idle 2-3K RPM after you get it going, low end bog, high end you'd never know it had a problem...
Symptoms if anyone is interested are: 3-4 pulls to start, low idle first couple of times you start it (sometimes stalls), high idle 2-3K RPM after you get it going, low end bog, high end you'd never know it had a problem...
What did the adapter boot for that cylinder look like, is it cracked?
maybe I missed it, but is it a 05?
little crack but not all the way through...should last the rest of the winter...but if I can get them before I get all the other parts I'll change them out now.
It's a 2005.
Seemed to happen just after/while breaking a belt a 3/4 throttle. Actually it was more like obliterating! The belt blew into a million pieces except for one long strand that managed to wrap around the crank shaft and the secondary at the same time stopping the motor...sure was fun to get that out at 3am on the trail. There is no problem with the crank.
It's a 2005.
Seemed to happen just after/while breaking a belt a 3/4 throttle. Actually it was more like obliterating! The belt blew into a million pieces except for one long strand that managed to wrap around the crank shaft and the secondary at the same time stopping the motor...sure was fun to get that out at 3am on the trail. There is no problem with the crank.
What does the reed look like?
Didn't look at it. I'll check in the morning...
crank seal out!!!
Crank seal is bad. when you blew the belt the kevlar cords got wrapped up behind the clutch and cut the crank seal. thats the problem. Need to reseal the crank case.
Probably screwed your crank. Do not start or run it any more!
Crank seal is bad. when you blew the belt the kevlar cords got wrapped up behind the clutch and cut the crank seal. thats the problem. Need to reseal the crank case.
Probably screwed your crank. Do not start or run it any more!
He said mag side?
I don't have a problem with the crank or the seal...there no sign of any problems there. The crank was already upgraded to the larger size 4-5K miles ago...probably the only reason it's still in tact now.
Any chance that something could have fallen down out of the VES system and caused this? The fork looks ok (clean them regularly) but I'm wondering if some exhaust gunk from the VES walls could have fallen off and caused this?
Any chance that something could have fallen down out of the VES system and caused this? The fork looks ok (clean them regularly) but I'm wondering if some exhaust gunk from the VES walls could have fallen off and caused this?
J
jskattum606
Well-known member
I dont think it would have been exhaust ressidue. I would say it looks more like a cold seize. Do you always let the motor wram up before taking off?
CANT SEE THE TOP OF THE PISTON TO WELL IS IT BURNED DOWN ON THE TOP SIDES? LOOKS LIKE A LEAN CONTION TO ME.OR LACK OF OIL .
Reeds look fine...
Could have been lean...oiler lines were slightly off but the plugs looked great; no sign of a lean burn.
Anyway, Polaris piston, o-ring and gaskets should be here by tomorrow. I didn't get the cylinder apart until last night and it was scored a little so I ordered one from Adrian Bernard; it should be here tomorrow. I also ordered throttle body boots. I'll set up the oiler while the engine is out (I know I didn't have to take the engine out but wasn't that much more work and makes it alot easier to get at stuff). Also, I'll clean the VES again.
BTW, compression was equal on both cylinders before I took everything apart (approx 125 psi: tested warm engine, both plugs out, WOT)
Could have been lean...oiler lines were slightly off but the plugs looked great; no sign of a lean burn.
Anyway, Polaris piston, o-ring and gaskets should be here by tomorrow. I didn't get the cylinder apart until last night and it was scored a little so I ordered one from Adrian Bernard; it should be here tomorrow. I also ordered throttle body boots. I'll set up the oiler while the engine is out (I know I didn't have to take the engine out but wasn't that much more work and makes it alot easier to get at stuff). Also, I'll clean the VES again.
BTW, compression was equal on both cylinders before I took everything apart (approx 125 psi: tested warm engine, both plugs out, WOT)
Just because it doesn't look lean now doesn't mean that it wasn't lean at some point. I don't see any wash on the top of the piston, is it there and the pic just doesn't show it?. The fact is, at some point the piston had to get hot enough to expand and seize (Causing those black streaks on the piston and cyl.)
Good call on the wash, I was noticing that too.
If the TB boots aren't cracked through, then how would he be running lean? I was under the impression that the 900 fuel maps were pretty much dead on...
Could a clogged injector cause this with the symptoms mentioned?
Thanks guys. Seems like popular consensus is directed towards a lean condition...if so, it may have been the oiler lines being off a touch like I mentioned earlier. I'll tune them before I put it back together.
BTW, someone was asking if I let it warm up before riding...the answer is yes! I always let it warm to at least 100 degrees F prior to riding and never let her have it until I've been riding for a bit (unless of course it's already warm).
Just got the pistons, o-rings and gaskets...Cylinder should be here tomorrow and the other parts should be here Thursday.
She should be ready to go for a trip up north on Friday!
BTW, someone was asking if I let it warm up before riding...the answer is yes! I always let it warm to at least 100 degrees F prior to riding and never let her have it until I've been riding for a bit (unless of course it's already warm).
Just got the pistons, o-rings and gaskets...Cylinder should be here tomorrow and the other parts should be here Thursday.
She should be ready to go for a trip up north on Friday!
I can't say that I could tell the difference between normal/abnormal piston wash. Does anyone know where there are some good pics demonstrating the differrence?
A clogged injector could. Also just having an old fuel filter WILL cause it to go lean under certain conditions.
Post 4 shows what good wash looks like.
http://www.snowestonline.com/forum/showthread.php?t=110110&highlight=piston+wash+pic
Similar threads
