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Management at the site asked me to do a little write-up about my crankcase pressure problem and what myself and all parties did in helping find, and relieve my bike of the problem...so here goes...

The very first indication that my bike had any sort of a problem was when my butt dyno felt that something was a little off. It felt as if the bike was falling flat in the upper RPM's. I thought it might be the jetting. I messed with the jetting for quite a while to try and rid my bike of the problem...all to no avail.

Next, I took my bike to Precision Motorsport's Mobile Dyno in Culpeper, VA to see if Matt could master the jetting and take care of the problem. After trying several different jets, I ended up leaving the dyno with a seemingly incurable dip starting at around 7500 RPM...this was the second indication of the real problem.



Now, I knew the problem my bike had was not jetting related. So with the help of my Dad, I began checking everything that I could personally check.
- electrical connections
- valve clearances
- timing
- spark plug
- obstructions in the exhaust pipe
- obstructions in the intake, carb, or ports
- abnormal wear on any parts
- fluid levels
- chain lube

It was during this time that I found the third indication of the real problem. After removing the exhaust system from the bike, I found an oily film sitting in the exhaust port which was still sticky from the ride I had taken early that day. I thought that maybe my rings were going bad since the piston was a 2 ring design and had been in the bike for over a year. The bike did not smoke at this time, which was very odd; but I dismissed the finding prematurely concluding that the rings were bad causing the bike to burn some oil.

After all those things checked out just as they should, the parts swapping began:
- cams
- ignitions (Thanks Brian @ WPP Racing)
- airboxes
- intakes
- air filters
- clutches
- clutch springs
- engine and transmission oils
- even more jets (just in case)
- re-plumbing of the crank case and valve cover vent lines, replaced the hoses, fittings, and filters with brand new ones

After all of those parts swaps did not make a difference, and after countless calls to WPP Racing and Wicked Motorsports, I personally, could not go into the engine any further. I am a computer geek, not a gear head.

Thoroughly checking all of those things and swapping all of those parts took months of my time. I stayed on campus at a University 1.5 hours away from home taking 9 credit hours of classes and working full time (40+ hours/week). I would come home on Friday nights and start working on the bike pretty much non-stop (just to eat and sleep) and finish up on Sunday afternoon just before heading back to school.

After many months of trying to find the problem myself, Wicked Motorsports agreed to take my bike on to see if he could find out what was going on with it.

He started swapped everything else top end related:
- heads
- valves
- valve springs
- pistons
- cams (including degreeing my current cam in)

During this time he was able to put my bike on a load dyno, and he even threw a Web 208 in to see if it would get rid of the dip.

While Wicked Motors had my bike on this dyno with a load on it, the bike sounded sick and made sort of a gurgling noise in the crank case.

Another tear down revealed that if he took the cam chain off the cam gear, and turned the engine over by hand, using his finger as the "cam gear," his hand would be soaked with oil in just a few seconds, like there was something pushing the oil up from the bottom end. This had not happened with any previous bikes he had worked on.

Wicked Motors knew there was something up with the bottom end at this point. He had exhausted all possibilities from the air box to the exhaust silencer to the cylinder head to the piston. He dove into the bottom end and found the problem. (Pictures courtesy of Wicked Motors)





The first picture is of the relief valve in the oiling system. If the oil cooler gets some blockage, it forces the relief valve open and returns the oil directly back to the crankcase. You can see the black piece of material to the left of the spring in the second picture...this piece was in the relief valve holding it open, bypassing the oil cooler and dumping the oil directly back into the crankcase. The piece of material looked to be a plastic piece off of the timing chain guide....possibly an imperfect chain guide mold...a piece that chipped off and eventually found its way into the relief valve.

This explained the flat spot in the upper RPM's, the dip in the dyno curve, the residue in the exhaust port, the gurgling sound from the crank case, and the oil soaked cam chain.

After the relief valve was unplugged, the oil level in the bike dropped a 1/2 quart. After the engine oil was topped off, and the bike was taken for a ride, it was cured. No more oily film in the exhaust port, no more gurgling, it no longer sounded sick, and...no more dip. The bike ran right. And now the dyno curve looked like the below. (Orange curve...dynojet dyno)



WPP Racing and Wicked Motors really helped me out with this whole thing. If it wouldn't have been for them, I would have never found the problem.

I must give credit where credit is due. Thanks to my Dad, WPP Racing, and Wicked Motors!
 

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wow, interesting... Ive always wondered why the oil design pushes the oil through the filter and not pull it through. Seems safer to me, but what do i know about engine designs? lol
 

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Great catch WPP/Wicked :thumbup: ...I can see how that could have been frustrating trying to track it down :banghead:

Let's hope no one else has to go through the same scenario...but if they do...we now have some great info to help diagnose the problem thanks to all involved. :yes
 

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wow...
thanks
 

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what happened to the pictures? Also i think there may be something wrong with mine but im no sure. Im getting oil in the airbox? Ive heard this could also cause that, anyone hear of this?
 

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Thanks for restoring the pics Gary.:yes
 

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Great catch WPP/Wicked 👍 ...I can see how that could have been frustrating trying to track it down :banghead:

Let's hope no one else has to go through the same scenario...but if they do...we now have some great info to help diagnose the problem thanks to all involved. :yes
I'm going through the same scenario right now on a fresh rebuild. New everything down to oil pump, one way valve and relief valve...burning oil like crazy. Increase crank case pressure.....driving me NUTS!!
 
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