scraped piston possibly from lean jetting?

[pasedogg]

when i looked beyong my reeds on both pistons they have identical scrapes in the exzact same spot, i found this pis on a website, my scrapes look about the same as the scrape on the left.what should i do. i have not compression tester.Im gunna hone i think or bore, get new pistons.hopeflluy its from jetting and not sand as the airbox was filthy with sand past the filter.

Edited February 15, 2008 by pasedogg

[pasedogg]

heres the site i got the pic, its a good one. i got one scrape that i can see on each piston

http://www.smellofdeath.com/lloydy/piston_diag_guide.htm

[violentholeshot]

heres the site i got the pic, its a good one. i got one scrape that i can see on each piston

http://www.smellofdeath.com/lloydy/piston_diag_guide.htm

 

had a left one do the same thing to me,the bike tossed a plug while riding,you say it's both cylinders,could you have an air leak? base gasget or intake

[Lepew]

I agree with the website on the issues that cause that type of scuffing. Was the piston skirt slapping? If you measure the skirt I bet you will find it is deformed. I had scuffs on the middle of the intake side when I purchased the bike then the next set of pistons I replaced had the four corner scuffs. I contributed it to cold seizure on both cases, I think on windy days on the dunes the bike cools too much on breaks between rides and should be warmed up before riding it hard again.

[dajogejr]

I was gonna say 4 corner seize... Are you letting it warm up before riding it?

[pasedogg]

ya i just got it, it came like that. i drove it maybe 5 minutes and its been parked since.i parked it because the jetting was way off. and while it was parked we decided to gut it since it was new to check everything out.then we saw the scrapes.so now its time for a rebuild..,this thing is parked until im satisfied its not gunna blow up on me..my buddy has horror storys with his banshee.all because he eqnored problems.

[Fireroad Express]

it kinda looks like a cold seize from not warming the engine up before you ride.

[FireHead]

I agree with the website on the issues that cause that type of scuffing. Was the piston skirt slapping? If you measure the skirt I bet you will find it is deformed. I had scuffs on the middle of the intake side when I purchased the bike then the next set of pistons I replaced had the four corner scuffs. I contributed it to cold seizure on both cases, I think on windy days on the dunes the bike cools too much on breaks between rides and should be warmed up before riding it hard again.

That picture shows a piston to bore fitment problem. Either the piston was not the correct size for the bore or the bore was not machined to the correct dimensions for the piston.

 

Technically speaking, there is no such thing as a cold seizure. Cold seizure is something that happens when a bore or piston is not the correct dimension in relation to each other, but is close enough to function relatively properly under normal circumstances. :geek: