Wiseco piston thread cont. *WITH PICS*

You can see a small chunk missing at the top...

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2011-06-02_20-26-02_925_Elbridge.jpg

Intake side...

2011-06-02_20-25-50_143_Elbridge.jpg

Exhaust side...

2011-06-02_20-25-34_870_Elbridge.jpg

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This plug was put in before this ride. That is why it is lightly colored but it still looks pretty good...

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This is the plug that I was running all year...

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Head looks pretty good.. doesnt really look like it got hot or anything...

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The cylinder I just had replated is trashed...

2011-06-02_20-16-03_627_Elbridge.jpg

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I actually still had the other two wisecos that let me down... The bottom ring sucked in on all of them.... this time was the worst..

2011-06-02_20-27-10_401_Elbridge.jpg

Last year everything on the bike was stock... I was running a 48 pilot, needle in the stock postion, I did lean the main out to a 165. I ran 93 mixed at 40:1 with klotz r50. I thought the rings were collapsing due to detonation and/or being too lean (even though the plug always looked good). This year the motor is still stock (besides a pipe and reeds) I started running a 50-50 mix of 100 and 93 and switched to klotz supertechniplate and mixed it at 32:1. I put the jetting back to stock ( 48-needle 3rd notch- 168 main) I had no bottom end at all and the plug was black so I went to a 45 pilot and went up a notch on the needle and that its where its at right now... I just dont know how this happend there are no signs of being lean or detonation... I just dont get it...

Um unfortunately its looks like you were indeed running hot.

Just my edamacated guess....

Your plug is white, indicated it was hot.

The crown also shows you were hot and the underside of the piston looks to be run hot as well.

Just as an example, here is what my KX250 piston looked after 80 hours:

bottom.jpg

piston-1.jpg

Head.jpg

All that black carbon means you getting hot enough to "cook" the oil.

That plug looks light because it was just put in.... I took a piture of the plug that was in there all year and you can see it is black. and every motor I have ever taken apart has some black carbon on it... but yes the under side of the piston being so black worries me but I just cant see how it got hot?

The underside of that piston is REALLY black. She got good and hot.

I can see white on the tip, or is that an illusion?

I can see white on the tip, or is that an illusion?

The plug that I had just put in there is half white and half brown... The plug that I have been running all year is black. The white on the tip is from the flash on the camera.

Can you get a better pic of the 2nd plug? Maybe no flash?

Yeah ill try. Its just all black, not wet black but a dry black...

The piston tells the story. How do you know power-seal didn't get the bore right? You have some kind of bad luck with Wiseco but I think you should send those pistons in and get an analysis. They can test the metal and see if it did indeed get hot. Maybe you have been running hot and not known it?

Perhaps powerseal didnt get it right. I have had good luck with them in the past and didnt bother to take any measurements...but im starting to I wish I did. Yes it definitely does look like it got hot I just do not see how or why? The last two pistons that collapsed a ring happened before anyone touched the cylinder.

Lets see pics of the undersides of those 2 pistons.

Normally you get a black spot when it's been running hot enough to do damage. Your entire piston underside is black.

Lets see pics of the undersides of those 2 pistons.

Normally you get a black spot when it's been running hot enough to do damage. Your entire piston underside is black.

I did check the underside of them... they are black as well but not nearly as black as this one. If anything it should have been running hotter last year with the leaner main and the 93...

Even if they were hot I don't see why it would explode the rings. Maybe your clearance and ring gap was just too tight

you're just running too lean.. so it got hot, too hot.

you know on a 2stroke i prefere a black sparkplug.. you'll maybe loose a horse or 2-3

but hey, at least it will never seize!

i run all my bikes just a little too rich, you really don't notice that while riding

and wish i had some pics from my pistons coming out of my rm250 91'

NOT ONE mark on it!

You were running 40 to 1 then went to 32 to 1? Then went leaner on pilot and needle? Wouldn't that lean it out and run hotter?

if my two stroke plug looked like that I would go into full panic mode and start checking for clogged jets

You were running 40 to 1 then went to 32 to 1? Then went leaner on pilot and needle? Wouldn't that lean it out and run hotter?

Yes I was trying to lean it out... It was running very rich so those jetting changes I made wouldnt have leaned it out to the point that something like this would happen..

:ride:

The black spot under the piston is a tell/tell sign of it running lean.

I think it got 'leaned' out.

Have you checked your radiator cap lately. Go to a radiator or auto repair shop and ask them to presure test the cap. Your piston seized on the intake side too, also burned the oil on the underside of the piston. This usally is caused by overheating. Could be a cooling system failure, ignition, or an octane thing too. The shiny spot on the top of the piston in the middle of the carbon is suspect of detonation along with the small shiny pits in the head. Look at it really close with a magnifying glass to look for any deteriation.Since you have the piston and head where you can see them, plug readings dont matter anymore. The best way to diagnose proper jetting is from the burn pattern on the top of the piston. Your seizure is almost the same as what I did to my 03 other than mine broke a ring in the process but didnt seize on the intake side. Your jetting might be ok because detonation can be caused by other factors like ignition timing too advanced or octane of fuel inadequate.

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