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How does this piston look?

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Looks pretty good. Fairly minimal piston wash. Are those deposits on the crown, or just discoloration, or a mixture. I would say you're jetting is close to ideal, but on the safe side of rich.

Wiseco piston? Did you happen to re-ring it during the 75 hours? I would be interested to see the exhaust side skirt.

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I did not post the skirt because i only wanted input on the burn. I will bost the skirt later.

Well the burn on bottom of the crown indicates you got the cylinder temps to high at one point. But the pattern is minimal enough I would not worry about it. The wash on the top of the piston shows you're rich, and it also shows that the ports flow differently. This is not that uncommon. Also there appears to be minimal deposit formation which means your cylinder temps are high enough to effectively burn off the residual oil, which indicates you're close on your jetting.

Also I notice there is no wash around your boost ports. I would assume you ride in the lower part of the rpm?

Edited by GMO397

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Looks pretty good. Fairly minimal piston wash. Are those deposits on the crown, or just discoloration, or a mixture. I would say you're jetting is close to ideal, but on the safe side of rich.

Wiseco piston? Did you happen to re-ring it during the 75 hours? I would be interested to see the exhaust side skirt.

I would say a mixture but more discoloration. Yes its a Wiseco piston and i did not re-ring it.

Well the burn on bottom of the crown indicates you got the cylinder temps to high at one point. But the pattern is minimal enough I would not worry about it. The wash on the top of the piston shows you're rich, and it also shows that the ports flow differently. This is not that uncommon. Also there appears to be minimal deposit formation which means your cylinder temps are high enough to effectively burn off the residual oil, which indicates you're close on your jetting.

Also I notice there is no wash around your boost ports. I would assume you ride in the lower part of the rpm?

Yes i do ride in the lower part of the RPM's. I ride tight and rockey single track and some times i get it wide open in between trails. What i dont get if im jetted realy well what do i get so much spooge out of the exhaust? Here are the skirts.

2012-02-20_18-33-44_691.jpg

2012-02-20_18-33-34_566.jpg

2012-02-20_18-33-24_807.jpg

2012-02-20_18-33-13_628.jpg

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I would say a mixture but more discoloration. Yes its a Wiseco piston and i did not re-ring it.

Yes i do ride in the lower part of the RPM's. I ride tight and rockey single track and some times i get it wide open in between trails. What i dont get if im jetted realy well what do i get so much spooge out of the exhaust? Here are the skirts

Do you have a spark arrestor on your silencer? What's your mix ratio and what premix are you using.

While you have your cylinder and piston off, peak down in the crankcase below the crank. There should be a pool of premix oil down there. Use a Q-tip on a screwdriver to measure the depth of this pool (or any dip stick). The pool depth should be around 1/4". If it is more than that, you should use more premix in your gas and vise versa.

I would guess you're getting a bit of spooge from lugging the bike around on the tight trails. Your mix ratio might be oil rich.

It looks like you had a bit of blow-by around your rings. It is not excessive for 75 hours though. I would maybe suggest a re-ring halfway through if you're savy about the running condition.

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Looks pretty good to me, personally I would feel really good about that piston if it came out of my bike.

I will second the re-ring half way through the life of the piston. It will help performance quite a bit.

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cookiemonster -

Thanks for the pictures, this is a relatively happy piston. With those hours, it appears that you are taking good care of the intake and watching jetting. There is evidence of heat, but nothing alarming.

Keep up the good work!

Dave

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Yes i do ride in the lower part of the RPM's. I ride tight and rockey single track and some times i get it wide open in between trails. What i dont get if im jetted realy well what do i get so much spooge out of the exhaust?

If your still getting a lot of by product in the exhaust and leaking out of the muffler your still too rich at some point of the throttle angle. You will need to do specific throttle angle tests to find out where. I would guess it is in a part where you do not spend the majority of your time (possibly pilot jet) but since you do not spend the majority or your time making max rpm and heat, the unslightly byproduct will not cook off. I would say you are about perfect for your type of riding but if you want to get rid of the spooge you will need to lean out somewhere and at this point I would not feel comfortable just guessing, I would do the plug chop tests.

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Thx for all the great replies. Here is my jetting:

Main 175

Pilot 45

Needle N3EJ third clip down

Mixture Screw 3/4 to 1 1/4 out

Using Maxima Super M at 32:1 and 91 octane gas

I have tried the JD Red needle in 1, 2, 3 and 4th clip positions (From top) and I have also tried N3EW 1, 2, 3 and 4th clip position and as of right now the N3EJ seems to be the best. The bike runs great but feels slight fat in the mid but if I try 1 leaner clip position or leaner needle it will ping in the mid if I’m slightly lugging it (it’s not chain slap either). I have been thinking going to a 48 pilot because it will lean surge at times at idle and when I start the bike when cold and with the chock on the RPM's will go really high(so I keep my hand on the kill switch). I us to run a 172 main and 42 pilot but it felt to lean for me. When I went to where I’m at now the spooge is a lot better. So I was thinking that now I’m richer it is keeping the engine temps lower and not burning all the oil but letting it drop to the crank case( I might be totally wrong on this). So what do you all think I should do with my jetting to stop it from spooging and lean surging? When i was inspection the reeds to day I noticed that the rubber on one side of the reed block where the reeds seal as a lot of little cracks. From the marks on the reeds it looks like its sealing. It got me to thinking this is my problem with fine tuning the jetting. Here is a picture of the reed block. I hope you all can see what I’m seeing. Also sorry for the long winded post.

12012-02-22_16-27-26_628.jpg

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cookiemonster.

For what its worth, my 06 pinged under a load and when it got colder pretty bad .Even with richer jetting till it was too blubbery.

It all went away after i checked the timing and found it was wayyy off.

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I was just going to suggest raising the clip one position but you beat me to it. I missed that whole sentance. Def. keep your ears open for any signs of pinging though

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cookiemonster.

For what its worth, my 06 pinged under a load and when it got colder pretty bad .Even with richer jetting till it was too blubbery.

It all went away after i checked the timing and found it was wayyy off.

My timming is spot on. That was the first thing i check years ago.

So what do you all think of the Reed Cage? IS it ok to still use?

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I wouldnt worry about it too much, looks like it got a little water on it or something causing it to decay prematurely. As long as it doesnt cause any significant gaps between the petals and the block you should be good to go. Ive seen several cages in similar condition before.

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I wouldnt worry about it too much, looks like it got a little water on it or something causing it to decay prematurely. As long as it doesnt cause any significant gaps between the petals and the block you should be good to go. Ive seen several cages in similar condition before.

I was kind of thinking the same thing since i did not see any gaps between the reed and the block.

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