What Caused This?

99669viper

New member
Joined
Dec 22, 2009
Messages
36
Age
58
Location
Soldotna, Alaska
Need some advice as to what caused the center piston failure on my STOCK 2003 SXViper Mountain with less than 1900 miles on it.
 
There are many possibilities. We would need quite a bit more information in order to help you.

Did it fail on the first ride out this season?
What fuel were you running?
I see you are from Alaska. What was the temperature?

Pictures of the piston would be beneficial to us.
 
Did it burn in mid range cruse?? or a long WOT pull(racing/hill climbing
???) are you jetted right for your temp and alt.?? runing good fuel with clean carbs??more info,pics.........
 
Pics

Was easy trail riding in 25 degree temps nothing crazy. First part of the trip sled was running great then it felt like I lost a plug. Checked em and they looked good and continued on until she died. I have a pic attached this time.
 

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Looks like a lean burndown having the exhaust side of the piston melted like it is... Looks to be melted down there quite a bit. Have you cleaned your carbs yet this year?
 
99669viper said:
Was easy trail riding in 25 degree temps
Thats where 90% ot the burns will happen(mid range cruse,on the needles),that temp is cold(runs leaner) but the other two holes look rich?? how did your plugs look when inspected? any air leaks in that cyl?

stock sled and jetting?????
 
pull the jug, and post some pics of piston/cylinder all sides, it looks to me like you lost a ring by the clean break on exhaust side
 
Pull apart #2 carb and look for clues. Just because it didn't blow on the first ride dose not mean it wasn't due to dirty carbs. This year everyting in my carbs looked great except for some little gobs of gew which fromed on the plastic around the main jets. Had any of these gobs ended up in a jet I would probably be taking photos of a burned piston. The main reason I cleaned this year is due to the many stories of burned pistons due to dirty carbs.
 
I am with the guys on carbs...the outside cylinders look rich and the center was not!!! Check your carbs bet they are clogged.
 
Well I fixed my Viper engine problem and bought an Apex that I will be picking up on the 26th. Thanks to all of you that responded.
 
99669viper said:
Well I fixed my Viper engine problem and bought an Apex that I will be picking up on the 26th. Thanks to all of you that responded.


good way to fix problem lollll :letitsnow
 
modsrx said:
good way to fix problem lollll :letitsnow

It was a deal I could not pass up and I wanted to get back on the trail ASAP. This will also allow me to fix the Viper at a leisurly pace without having to panic that winter was coming to an end. When i figure out what happened I'll be sure to post the results. Until then I’ll see you on the 4 stroke side of the forum.
 


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