09 XT 25k miles, valvetrain issue

[motoguy]

I just bought an 09 XT with 25,000 miles. Amazingly clean bike. Seller said it stopped running on him during a ride. He took it to the shop and it has no compression in the rear cylinder.

I scoped it when I brought it home and it looks like the exhaust valve in the rear cylinder kissed the piston. Edge of the valve is curled enough to prevent it from seating. So that would explain the lack of compression. I slowly turned it over and noticed I was not getting any movement on any of the valves.

I asked a friend of mine who is more knowledgeable about Buell / Harley land. He said it’s been 17 years since he was a tech so he might be fuzzy, but it sounds to him like a possible broken pinion shaft which caused the valves to hang which resulted in the contact.

I realize at this point I’m going to have to drop the engine and pull theads and check everything out, but I’m not familiar with this pinion shaft situation. If there’s a problem with the shaft, how much of a PITA is the repair?

I have a spare ‘09 engine from the salvage 12R, but if the engine repair on the XT isn’t too disasterous I’d rather repair it.

 

[Cooter]

IMO the easiest thing is to just swap the engine with the one you have available. Much like a bathroom remodel... a re-build will snowball with the might-as-wells, sometimes thats good, sometimes its bad, but it's always more expensive that you want it to be.

 

[Barrett]

2009 SM Fig 3-132 for visual.
2009 XB four cam gears driven by a pinion gear on crankshaft end. 2009 oiling system is NOT driven by this pinion as in pre-2008 model years. The pinion gear is "keyed" to the crankshaft key-way. Simply remove cam chest cover and check for integrity. Very easy to do on the 2008 and up XB's.

 

[Kurlon]

If the pinion gear came free, I'd assume no cams would turn, front or rear? Is it just the rear valves not moving, or has the front stuck as well?

 

[motoguy]

If the pinion gear came free, I'd assume no cams would turn, front or rear? Is it just the rear valves not moving, or has the front stuck as well?

Not sure on exhaust side, but with borescope down the throttle body I have no movement on either intake valve when turning the engine over. I'll pull the cover and check the pinion / shaft situation. With no movement of valves and the PO's statement of "it just stopped running like I hit the kill switch" I'm thinking the pinion / shaft makes the most sense.

 

[Kurlon]

Ooofh, yeah, sounds like cam chest exploration time.

 

[motoguy]

2009 SM Fig 3-132 for visual.
2009 XB four cam gears driven by a pinion gear on crankshaft end. 2009 oiling system is NOT driven by this pinion as in pre-2008 model years. The pinion gear is "keyed" to the crankshaft key-way. Simply remove cam chest cover and check for integrity. Very easy to do on the 2008 and up XB's.

Thank you