Update: Bought a new compression tester since I needed the 10 mm adapter. Slightly nicer unit, but not professional grade. Cost $47, fwiw if anyone is thinking of getting one.
To review, the dealer said my compression values were:
#1 - 155
#2 - 157
#3 - 165
#4 - 152
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My tests:
Dry test, cold engine:
#1 - 165
#2 - 165
#3 - 175
#4 - 160
My numbers seem slightly higher than the dealers. Possibly due to the gauge.
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Wet test, cold engine:
#1 - 180
#2 - 175
#3 - 185
#4 - 170
All up some, but not dramatically, suggesting that there is some ring wear, which is expected, but not a huge amount.
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Dry test, hot engine:
#1 - 169
#2 - 164
#3 - 160
#4 - 155
Oddly, this is the only test where the #3 cylinder isn't higher than the others. I do note that the variation between cylinders isn't large enough to concern me. Pushing the limit of the shop manual's range though.
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After doing the tests, all of which were done with a fresh Yamaha air filter in place, wot, injectors unplugged and the same test gauge, I attached some vac lines to the TB sync ports and sucked in some top end cleaner, then shut the bike down. I don't have the option tonight to leave it overnight, but will go back out later and suck the rest through the engine, then take the bike for a ride, toss some ring free in the gas tank and fill it up, then do some freeway runs with high rpm and wot. Heading out on a ride at 0400.
The idle is still uneven. (It wasn't when I dropped the bike off, though the shop says they noticed it.) The cam chain tensioner is still noisy, more than ever in fact. Bike rides mostly ok, but doesn't seem to want to let the rpms drop when you close the throttle. Almost makes me wonder about air leaks. Both the erratic idle and the not wanting to drop on throttle close would support that. Pull the clutch in and the rpms drop. I did double check that the throttle cable had slack. No issue there.
Erratic idle could be many things, from simple bad spark plugs, to mis-adjusted valves. (there's a scary thought)
Right now, what I'm seeing leads me to believe that more of the issue is valve related. Either carbon build up, or??
Also a correction - My bike does seem to be using some oil. It's right between the hi and low on the sight glass. Normally when full, it's closer to the top mark. This is after 6500 miles though. Never gone that far before between changes. Normally right at 5k miles. Not using a lot of oil, but using some.
More after the weekend and I'll put on 1k or so, then test the compression again. Still waiting on the cam chain tensioner to show up and get installed.