crank case breather

[99_300ex]

I just bought an 05 450 it has a 13:1 piston and a cam i deiced i would start off by changing the oil so i got the good honda stuff and before i even started i took off the fill cap on the trans side and it had pressure built up so i just went ahead and changed it and took it out for a spin and it did the same thing so i checked all the crank case breathers and they seemed fine has this happened to anyone im kinda worried and hope someone out there has some sort of solution thanks.

[99_300ex]

come on guys somebody has to know this it would be very appreciated. all it takes is just to go out start and ride for like 5-10 min and mine will gain pressure.

[ss440ex]

Both of mine do the same thing....
The manual says to remove the fill first. doe`snt it !

One is a new rebuild....and I did ck all the vents-tees-and lines.

[99_300ex]

so this is probably not really a big deal then?

[ss440ex]

I would`nt worry about it....

[ride_red_510r]

i would worry about it. mines doing the same thing you do it long enough and you will get blow by i had a bad oil seal ring on my piston. which eventually caused it to spit out into my airbox becareful man.