2013 R, low compression

Hey folks, I've got a 2013 wr250r that won't start.

History:
10K total miles, though the gearing is way up so is probably 12K. The last 3K were by me.
The bike had intermittent cold slow starts where it would crank for a bit before starting up.
Has FMF header, pipe and fuel programmer.

Bike was running last week. We had just done a ride up around Mt Hood Oregon. About 150 miles of pavement and 35 miles off road. I didn't notice anything in particular that was off. I did an oil and filter change when we got back. I went out to start it this morning and it wouldn't start. The oilchange was probably very overdue and I can't confirm 100% that the level was full. I assumed it was from the last time I checked. It hasn't been smoking or leaking. It does leave me smelling a bit like rich exhaust or maybe a little oily after freeway runs or high rpm off roading.

Tried WOT and that didn't help. Checked spark, its good. Checked compression and its about 30psi with the throttle fully open. I removed the throttle body and checked valve clearances. They are all within spec but on the tight end of spec. With no throttle body and a teaspoon of oil in the cylinder, its about 60psi compression. The motor is cold so I know compression won't be very high, but I typically expect more than that, even cold.

I am an experienced bike mechanic but I don't claim to know everything so before I tear it down to inspect the cylinder and rings, does anyone have any suggestions on what I could try/look for?

Thanks from Portland Oregon!

Interesting...first thing I thought of was tight valves....hard starting is a sure sign of that. Short of taking the top end off and checking everything out (rings, piston, cyclinder) not sure what other options you may have.

Gearing works the other way, so unlees you have a very small rear sprocket, the bike would indicate more than the actual milage.
With 20% off you have 8000 actual miles.

Hope you update the thread with what you find if you decide to open her up.

Cmon guys, I was really hoping for the "You just flip the doohicky an then..."

CRFan1 wrote:

Interesting...first thing I thought of was tight valves....hard starting is a sure sign of that.  Short of taking the top end off and checking everything out (rings, piston, cyclinder) not sure what other options you may have.  

Yes, I was surprised about that as well. I did notice the intake valves were pretty dirty. I think the PO had it programmed rich. Maybe there is just some gunk on the valves and they are actually tight.

Jens Eskildsen wrote:

Gearing works the other way, so unlees you have a very small rear sprocket, the bike would indicate more than the actual milage.
With 20% off you have 8000 actual miles.

Hope you update the thread with what you find if you decide to open her up.

I am gearing challenged. I do know that the PO set it up for lower RPM higher speed and that the speedo indicates 50mph when the GPS says 60mph.
I have completely forgotten what he said the sprockets are and I haven't had any reason to change it so haven't counted for myself.

I will be digging into it in the next week or so and I'll try and come back and post some progress.

So... I figured out that the low compression was me being stupid about the auto compression release. So thats good.
Still doesn't explain the no start.

Someone on at WR250 facebook group said he had his cam chain skip a tooth because of low oil pressure and the hydraulic cam chain tensioner.
Mine looked ok, but I went ahead and pull the tentionser and reset the cam timing and now it starts right now.

Cleaning the throttle body and injector may have also helped.

Basically, I am confused and I don't know why it didn't start.... but it runs now.
Thanks for the input though!