Sorry for the lapse in time between posts!
On Saturday I picked up a leak-down tester from one of the local shops that I used to have a working relationship with. Actually, since they were cool enough to let me use their tools, I'll give SF Moto
a plug here- all the folks there are awesome. If you're in the bay area, and in market for a scooter, a used motorcycle, or aftermarket or OEM parts, give Eric, Andy, Tony or Thomas a call... they'll treat you right, and it's good to support businesses that care about supporting the motorcycling community, not just about selling bikes.
Okay, back to the matter at hand here... just moments ago, I finished the leak-down test. The results came as no surprise to me, as I've confirmed that everything above the intake valves is good, and everything below the exhaust valves is good.
This afternoon, I tore down the bike for probably the dozenth time since the issue arose. Everything went smoothly, and I hae to admit, I feel like I'm getting pretty efficient at tear-down and build-up of the 950 Adventure. A skill that admittedly, I've never really wanted. I got the crash-bars, fairings, tanks, carbs, air-box, and valve covers off. Pulled the plugs, and set the front cylinder to TDC. I bought one of those bolt-like tools with the allen end to hold the cylinder in exactly TDC a couple weeks ago, but couldn't find it... so I just lined up the dots and confirmed the lobe positions on the cams. Plugging the hose into the spark-plug hole was a cinch, and I hooked up the air to the tester. I could hear that there was a leak somewhere. Just to confirm, I pulled the header from the front of the cylinder. Yep, definitely an exhaust valve leak... a big one too.
Looking at the valves, I was surprised to see how grungy the ports and stems were. There is all sorts of hard, crusty build-up in there. It almost looks like this bike never had an air cleaner on it. I've had a look at probably a hundred or more heads, and have never seen anything like it. Looks like caked on dirt / mud / creosote. Nasty.
Anyways, problem identified. Now what? Does anyone with experience
have suggestions of where to (or for that matter, where not to) take / send the heads off for rework? I'm assuming that it's appropriate standard procedure to do both heads instead of just the one that's giving issues... can anyone confirm this? Since the bike will be torn down to the point where the heads are removed, is there anything else that might as well be done at his time while the engine is this far apart? FWIW, the bike has 12.5K miles on it.