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High Compression?

jeremywatco

Well-Known Member
Messages
33
Reaction score
8
Points
47
Boat Make
Yamaha
Year
2007
Boat Model
AR
Boat Length
21
Brought home a low hour 2007 AR210 few weeks ago. Been fun! Pulled the hours. They were at 190. PO said it was serviced in April but didnt have any documentation on it... so I did an oil change and plug change.

Starboard engine, plugs unscrewed with little effort at all. Like none. Used my compression tester on them and got 185-185-193-220. Retested the 220 multiple times and always got 220. Any concern there? On of the boots on the coil was partially missing.. there was enough to cover the plug but here was a good 1/2" missing off the coil

Port plugs were all TIGHT.. i ended up soaking all of them in PB blaster for a bit after hearing of broken plugs. They freed up after that. Port compressions were 190-200-190-200.

I torqued the plugs to 10 ft/lbs as thats the lowest my wrench goes. I hand tightened the coil bolts and gave them maybe an 1/8 of a turn after with my wrench.

Speaking of cylinders.. what is the layout? Is Cylinder #1 the one more forward on the engine?

Also... Starboard engine... 1/2 the plugs were pretty white.. half looked almost new.

Port engine.. all were oily. Not bad but all had oil on the threads. Checked oil level.. looked great.

Just curious about that 220 on the compression and oil on the port plugs. This was my craftsman compression tester.
 
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