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Discussion Starter #1
Well my 97 Sportsman had lost compression and when I pulled the top end....most of the skirt is GONE....I mean GONE....not a trace of any pieces in the crankcase, Cyl is scratched up alittle but 99% cleaned up with a hone. measures out at 3.271 so I lost .001, cheap STD kit to go back in with hopes everything else is ok. never used any coolant, or run hot. with only 1700 miles I need to find the original problem before sinking major money in a rebuild. Its been used more for utility work around the property with some mild riding. Anyone have some input or things to look for.
 

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Just curious to see the piston missing its skirt...can you post pics?

Sean
 

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There was some pics on here not too long ago showing the same thing. The pieces have to be in there some where. Have you had it since it was new. Maybe the previous owner removed the pieces and just put it back together.
 

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Well my 97 Sportsman had lost compression and when I pulled the top end....most of the skirt is GONE....I mean GONE....not a trace of any pieces in the crankcase, Cyl is scratched up alittle but 99% cleaned up with a hone. measures out at 3.271 so I lost .001, cheap STD kit to go back in with hopes everything else is ok. never used any coolant, or run hot. with only 1700 miles I need to find the original problem before sinking major money in a rebuild. Its been used more for utility work around the property with some mild riding. Anyone have some input or things to look for.
Gee I was hoping to see some pictures based on your title. But then I read your posting and got my hopes down. :veryhappy:
 

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The bottom of your cylinder is probably egged shaped, need to thouroghly mic out cyliner to see how much it needs bored,
 

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Piston skirts shrink over time and heat cycles. Then they start to slap more and get brittle and break. Nature of the beast on a 2 stroke. As said, check the cylinder for out-of-round. Also, the stock pistons on them seem to be especially prone to broken skirts. Get a wiseco or other brand of forged piston for it and you won't have the problem again. The cast ones are the weakest.
 

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Discussion Starter #7
heres what I found



I have looked hard for any indication of anything bouncing around in the bottom and see none, the edges of the ports are clean as is the head, but the top of the piston is beat to hell. A friend that raced 2 strokes said I got lucky and it went out the exhaust...cant wait till the new one gets here to compare side by side....

Zimmerra.......Your sick and perverted.....qualities I look for in a friend
 

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I have to admit that I too was a little disappointed:naughty:
 

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Discussion Starter #9
Well its back together, fired up and runs, BUT bogs down at half throttle and back to the original wont shut off/ runs like crap issue....

from 11/2010
97 400L 4X4 wont shut off !!!!!

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at times it goes to running like crap and wont shut off with the key or kill switch, hot or stone cold both. ohm meter shows that the switches are working, and all connections appear tight and clean. bought it this way and replaced the battery and voltage regulator due to overcharging and blew all the lights. hunted back 8 pages in search and only found clean adjust the ECT, ( and the standard check the connections)
anyone have any help or suggestions?
TIA
Darrin
 

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You may want to follow the black wire, either from you run-start switch or key switch , to the cdi box and see if someone hasn't unplugged the wire. This negates the kill switch and will stay running.
Check the secondary coil resistance, you may have a faulty plug cap
 
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