07-03-2010, 04:00 PM #1
Mullered Piston, Whats caused it?????????? More Pic's
Went out on my ski today, still not holding its idle though
Went for a run doing 42 on the MFD then it died, started back up low speed back in, pulled the ski out of the water done some checks, pulled the spark plug and found a carboned up plug on the front mag (near steering)
Here's what i found when i removed the heads
Was it running to lean to cause that damage??, it hasnt damaged the bore so im guessing id get away with just a new piston and ring?? and gaskets??
Is this a easy job, what should i be checking to ensure it doesnt happen again?
Last edited by Cliffy; 07-04-2010 at 06:53 PM.
07-03-2010, 04:06 PM #2
I think everyone is going to say a lean condition. Have you done all the upgrades? It looks like it was trying to burn a hole.
07-03-2010, 04:10 PM #3
yeah i figured as much,
It has a triple pump, checked and clean the carbs a while back, set all carbs to stock position last weekend, run wicked took it out today and this happened, deep joy
07-03-2010, 04:18 PM #4
Are you running premix? If so I think you need to richen up the mixture since oil displaces fuel. If you are not, I bet the mag carb was not rich enough.
07-03-2010, 04:28 PM #5
na im still letting the ski do the mixing as it works well (well i thought it was)
So now im gonna get 1 new piston, can i get a stock one as the bore doesnt have any major scoring maybe a light score in one place but not deep or anything u wouldnt feel the mark unless u used ur finger nail but again its very slight nothing major
07-03-2010, 04:34 PM #6
- Join Date
- Oct 2006
- Cleveland OH
Cen is pretty rich. the PTO doesn't look lean either.
Something is restricting fuel flow to the MAG, or you had an air leak.
Check your carb filters and make sure to do a leak down test after you replace the piston.
07-03-2010, 04:44 PM #7
07-03-2010, 04:47 PM #8
07-03-2010, 06:31 PM #9
07-03-2010, 06:36 PM #10
No, an air leak meaning that the cylinder is pulling in air from somewhere other than the carb. This air doesn't have gas in it, so it leans air from the carb and burns pistons. Check around the cylinder base gaskets, the gaskets for the reeds and intake manifold and the gaskets under the carbs. Also look for any cracks in the manifold or any other possible spots that would leak.
Check your fuel line to that carb, and the carb itself for any restrictions in fuel flow.
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