I think people should pay attention to the color of your spark plug.  I'm thinking your plug is cleaner than 9 out of 10 plugs on here.  

I haven't pulled mine in 3 or 4 years.  I'm running leaner jetting than most on here and I bet mine still shows more carbon than yours.

Great write up and research as usual.

Is is possible that modern fuels don't create the same color on the insulator that we are use to seeing?

I can remember in the old days of leaded fuels seeing the inside of my exhaust pipe being a light gray color after a long trip where the system had been up to temperature for an extended period......now the tailpipe is always soot black.  Similarly the exhaust valves are ghost white - and I used to think a nice tan color was normal for the valves in a healthy engine.

I had just finished a long ride and reached the 7000 mile mark.  I decided that it might be a good idea to do a “HOT” compression check before I dumped the oil.  I generally do my compression checks cold and had never tried to do a hot check.  So, I pulled into my garage, set the bike up in the stand, pulled off the seat and fuel tank, quickly removed the spark plug, and did a compression check.

Shazaaaam!  That sucker pumped 245 psi.  Either I’ve got a big pile of carbon built up, or that “HOT” check makes one helluvalot of difference.  On the last service, it was 225 psi cold.  Best check compression again (cold).

A quick wipe with a paper towel showed that no significant flakes or chunks were on the drain plug.  The sludge simply smeared onto the towel.  There were no particles that had any visible dimension.  Just sludge/dust.  No indications of gear failure.

The spark plug looked the same as it did at 3500 miles.  It was darker than I would prefer, and the ground electrode was a super-light grey, some would say white.  It’s not the sort of coloration I am used to, but it seems normal for this engine.  No balls of metal.  No melted cement.  No fractures in the insulator.  No tell-tale signs of detonation.  All good.  The gap was .033”.  I left it as-is.

To check the plunger extension with this tensioner system, you must load up the forward side of the cam chain in order to ensure that the rear side is slack.  That’s easy to do.  Just rotate the engine in the normal direction of rotation until the intake valves start to open.  That loads up the forward side of the chain (drive side) and ensures that the rear side of the chain (slack side) is loose.  Now the tensioner plunger is completely extended.

So, position the intake valves about half-open.

I had to turn the jack bolt in 3-turns in order to restore the tensioner extension to 12mm.  That provides 1.5mm (.06”) back-travel on the plunger.  When the cylinder heats up and grows, it should tighten up the chain drive and the tensioner will have almost no back-travel.  As the system wears, the tensioner will extend and the back-travel will increase.  I plan to keep the back-travel below 4mm (.16”) by periodically adjusting the jack bolt.

I still have to be concerned about chain guide wear.  As I continue to turn in the jack bolt, the arc of the rear guide will get tighter.  That will change the angle of entry between the cam sprocket and the chain, and I suspect subject the rear guide to accelerated wear.  These periodic checks will help me project how quickly the plunger extension will increase.

This shows how much I had to turn in the jack bolt.  The distance between the red plastic on the pin gage and the end of the bolt is about 3mm (1/8”).

Things could get ugly real fast if the jack bolt ever came loose, so safety wire is mandatory.