any idea on this

[sick 96 250]

I took off the cyclinder to look at the piston and this is what it looked like.... Is this normal? If not could someone tell me why it is like this. Thank you

http://www.geocities.com/frkyflo/photopagetan.html

is that scortch mark ok or is that a bad sign of something and should the top of a piston look like that?

If this is bad could someone tell me what is wrong or what could possibly be causing this

THANK YOU

 

[Ryone]

The link didn't display a picture for me. It just said:

"We're sorry, but this page is currently unavailable for viewing.
If this site belongs to you, please read this help page for more information and assistance.

For general questions see our main help area, or search for other member pages"

 

[sick 96 250]

The link should be working now, so let me know

sorry for the inconveinence

 

[Bodge]

Looks like a load or crabon. How well did the bike run?

 

[RM 2 fif T]

the bike was extremely strong except when I went from closed throttle to wide open it would bog real bad then finally catch up. If i turned the ari screw all the way in and the idle down it would run great just stall soon as the gas was let off. I put a new piston in today anyways so I will try it out tomorrow after work to see if anything changed

 

[Mephisto]

Everytime i replaced a piston it looked like that on top. BUT if it is burned on the sides of the piston then you may have a problem.

 

[shnalln]

What does the underside/inside of the piston look like? If it's discolored too, then your probably running too lean somewhere.
Go HERE for info/causes of why your piston looks like it does.
Is that a burn mark on your crank? Wow, something is going on. It got really hot for some reason...Cooling system maybe?
Good Luck.

 

[sick 96 250]

the under/inside of the piston looks fine, i was just worried about the top of it and the scortch mark on the crank area. The cooling system seems to be fine but could this be do to the bike running to lean. When i bought it, it was jetted real lean it seemed with a 45 pilot and a 168 main with the needle on the 2nd clip when stock calls for 58 pilot, 172 main and 3rd clip.

 

[shnalln]

That could have done it, have you changed your pilot yet?

 

[sick 96 250]

yeah i put the pilot up to a 52 and main to a 168 so i will clean the carb today then see what happens when i get outta work.

 

[shnalln]

I bet that fixes you all up, let us know how it does.

 

[RM 2 fif T]

well the carb didn't make a difference, same problem. I looked at the spark i was getting by pulling the plug and touching it to the block to see if it was strong and i noticed i had to kick it over with some force to get a spark. How hard or light should you be able to kick it for a spark to appear. Also if it is a low spark with the old piston not having as much compression would it be able to handle the weaker spark and since now it has a lot of compression would it not be enough? Should i get the stator coil re wound or what? Keep up the ideas on this, i really appreciate it. :bang:

 

[RM 2 fif T]

Actually i think some antifreeze may have gotten into the bottom end so tomorrow i am going to remove it, and i bet it solves the problem :bang: :bang: :bang:

 

[RM 2 fif T]

got all the antifreeze out of the bike and it fired right up and stayed running except there was a lot of smoke coming out the exhaust. Could this just be the left over antifreeze burning up. The smoke was a whiting color with a tint of blue. :cool:

 

[monkeybutt]

Check your connecting rod/bearing for verticle movement, your crank should not be discolored on the side like it is.

 

[skagracer]

where are you riding looks like your jetting is way off what oil are you using / mixs what s your plug like the way you dicrib your throttle sounds like your rich on the top end do you have oil dripping out of your pipe

 

[RM 2 fif T]

I ride trails and some tracks that are mostly from sea level to 1000 feet. Running mobile MX2T at 40:1 right now, was at 32:1 and it was way to lean. Thats what i think happened to the top end and how the crank got a scortch mark. Since the new top end i haven't been able to get it out yet but i have the throttle response now so i just have to mess with different jetting. There was very little oil in the pipe so if anything i'm going to go with it was extremely to lean before and thats what cause all this. I think everything should be under control now hopefully