What is this stuff in my engine? *pics*

[Brodie]

Hey guys, I was cleaning my carb last night and decided to look at my top end a bit. I started by taking off my reed cage and noticed all this black flakey material in it. So I then took off the top of my jug and looked at my piston and it looks like that stuff got baked onto the top of the piston along with my spark plug. Any ideas what this stuff is? :-/

Reed Cage

Spark Plug

Cylinder Top

Piston

 

[89custom]

Its called carbon deposits. just normal build up over time. only thing that may not be normal is in the intake ports. maybe the plug too, usually pretty clean.

 

[yfz450bence]

looks like its the that paint just flaking off, see how its not black anymore. definetly some build up on the plug, either blow by from the piston ring or a crappy oil thats mixed too rich, 40:1 is plenty of rich for a good oil like amsoil or redline

 

[Mert]

what oil are you running, amsoil dominator? it has a really high flash point and doesnt burn very clean and leaves carbon deposits like crazy, switch over to klotz techniplate or a castor based oil

 

[Brodie]

I'm running Yamalube R at 32:1 with a block off kit. And yea yfz450bence, it almost looks like the inside of the reed cage was painted and it's flaking off into the cylinder. Are they supposed to be painted?

 

[yfz450bence]

ok nothing wrong with yamalube, but you will get carbon deposits over time, ya they all come painted on the inside and i dont know why, over time it starts flaking off. thats why porting looks nice cause they get rid of that black crap.

i run redline at 40:1, but thats just me of course, gonna do a top end rebuild soon and run redline right off the bat.

 

[lassek]

LOOL its just paint coming off on the intake... the rest is properly carbon deposits... It happens over time..


In the service manuel there is a timetable and guide how to clean it.. Its on regular maintenance...

 

[Brodie]

Awesome, thanks for the replys guys. I was just a bit worried because the previous owner didn't even know you had to put gear oil in the thing, so I was thinking maybe it was one of his drill hole mods or something.

 

[silverlight]

the piston looks alittle damaged, dunno but just looks like it some place at it, like piece is gone

 

[Brodie]

In which picture silverlight?

 

[89custom]

LOOL its just paint coming off on the intake... the rest is properly carbon deposits... It happens over time..


In the service manuel there is a timetable and guide how to clean it.. Its on regular maintenance...

i had no idea they painted the intake. thats stupid. i guess buying it used and buying a 240 kit they had no paint.

 

[seandubya]

Nothing wrong with the piston it's a normal intake skirt from what I can see.