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Hello

Just working my way through spankys jetting tutorial and I see this greyish goop dripping out of power valve discharge hose. Anyone else have this? I also have exhaust coming out of that hose all the time is that normal?

Bike is a Image1490995230.794501.jpgIMG_6294.JPG2017 250x

Thanks!

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The YPVS vent usually drips out darker/non foamy oil but since you've

no doubt been riding your bike in somewhat cool ambiant temps (Feb/March in Alberta)

 there is likely some moisture mixed in there as well from the engine's heating/cooling cycles.

Edited by mlatour
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It's just a drain for unburned premix.

I never thought about it but mlatour is right. Mine drips black in the summer and grey in the winter.

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I just got an X last week. I notice the "drip" after my first ride (after breaking it in). It was the same color as in your photo. It was like that for a few days.

Yesterday, I noticed the "drip" was a darker color (like normal spooge) and less of it. It was warmer yesterday, and I was using a different premix.

 

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Even Amsoil Interceptor which is known to have a low flash point / clean burning

will puddle up and leak out my 'jetted to almost perfection', not raced but still spirited MX ridden, high revving YZ125 YPVS drain hose.

I imagine in a lower revving, trail/off-road ridden YZ250X, the choice of a low flash point premix is even more important.

 

Add the fact that most YZ250 / YZ250X have a less than optimal squish band height, 

(to perhaps lower the octane requirement?) making combustion less efficient and more prone to spooge.

I've corrected that on my 125, shaving 0.20mm off the head, going from 1.35mm to 1.15mm

(it also bumped up compression 5psi). It made an already crisp running engine run even better.

Edited by mlatour

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All of my YZ250's have done this. My truck bed has a permanent dark spot in the bed from the hundreds of rides home. I keep a small cloth spill pad on the garage floor for the Monday morning drips.

One thing I've always wondered, where do other bikes deposit this spooge? My KTM's have a breather tube coming off the PV area but they exit the cylinder from the top and disappear up under the fuel tank. Do the other bikes simply dump the spooge into the exhaust to be burned off?

Edited by Texasxcrider
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2 hours ago, Texasxcrider said:

All of my YZ250's have done this. My truck bed has a permanent dark spot in the bed from the hundreds of rides home. I keep a small cloth spill pad on the garage floor for the Monday morning drips.

One thing I've always wondered, where do other bikes deposit this spooge? My KTM's have a breather tube coming off the PV area but they exit the cylinder from the top and disappear up under the fuel tank. Do the other bikes simply dump the spooge into the exhaust to be burned off?

Good question. My KTM has a tube running down the left side, but I never see any leakage from it. Just spooge out of the silencer. I've got to adjust the jetting on it a little.

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