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Piston and cylinder scuffs normal?

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My bike (2016 YZ250X) now has 30 hours on it and I looked in the exhaust port and saw this.
We can see the cylinder having a vertical darker line at the left in the picture, and the piston has these small scuffs.
Is it a big problem? How is the health of my engine?

I always used Motul 800 2T with premium gas.
During the first 20 hours or so I runned 30:1 mix, after that 50:1 because it was smoking way too much.
I also leaned the bike the 48 pilot, 175 main, and played with different needles depending on temperature. Now running N3CW clip position 1. Sea level

IMG_0238.jpg

IMG_0239.jpg

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The cylinder looks absoloutley perfect, and sure, you'll find a few scuffs here and there but it happens and its not like theyre bad enough to cause loss of compression, I'd just keep riding it if i were you

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Hello Sebas,

50:1 is quite a departure from 32:1, if mostly off-roading at lower rpms & engine load that's no problem

but if you regularly ride MX style / wide open throttle then I feel you'd be stretching your luck a bit (I'm old school...)

 

Not 100% familiar with Motul products but if the 800 is a 'racing' (high flash point) premix,

it may not be the ideal choice for a trail ridden bike and prone to smoke/spooge no matter the ratio or jetting.

 

That being said, those scratches are not too bad but as a comparative

the used pistons I remove from my YZ125 after 20-25 hours look brand new compared to yours.

 

If those were on the intake side I'd blame dirt/debris injestion past the air filter,

out of curiosity pull the carb and reeds and have a look on the intake side.

 

Edited by mlatour
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29 minutes ago, mlatour said:

Hello Sebas,

50:1 is quite a departure from 32:1, if mostly off-roading at lower rpms & engine load that's no problem

but if you regularly ride MX style / wide open throttle then I feel you'd be stretching your luck a bit (I'm old school...)

 

Not 100% familiar with Motul products but if the 800 is a 'racing' (high flash point) premix,

it may not be the ideal choice for a trail ridden bike and prone to smoke/spooge no matter the ratio or jetting.

 

That being said, those scratches are not too bad but as a comparative

the used pistons I remove from my YZ125 after 20-25 hours look brand new compared to yours.

 

If those were on the intake side I'd blame dirt/debris injestion past the air filter,

out of curiosity pull the carb and reeds and have a look on the intake side.

 

Yes the Motul 800 is a racing oil with high flash point so it might explain the smoke since I'm only trail riding (with frequent high rpm for 1-2 secs)
And also some high speed for a 1-2 km to get to the trail, but I do not stay pinned all the time, like, acceleration, coast(decel slowly), acceleration, etc..
On the bottle they recommend 50:1 for MX racing and 60:1 so I guess I'm am good at 50:1.

And when I was looking in the exhaust port, I could see a coating of oil on the piston as I was moving it with the kickstarter.

There is no spooge and with the jetting I'm using currently smoke is almost non-existant.

 

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As mentioned Motul 800 has a very high flashpoint.

I use Motul 710 and ride quite hard mixing it 30:1 when mixing 50:1 my crank last 200 Hours with 30:1 my crank last so far 400 hours. Plus the ring will last longer.  

 

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