location of water pressure bolt to remove and install the insert

[mudd minnow]

Hello,
I have a 1998 C 60 Yamaha 2 stroke and I purchased a water pressure guage for my motor. I also, purchased the insert to replace the bolt in the upper water jacket. I don't now which bolt to remove and replace the insert with. Can any one help me by putting up a diagram.

Top of motor looking at from the rear
1 Big bolt-----O
2 bolt---o o----bolts A
3 bolt---o SP o----bolts B
4 bolt---o o---bolts C
5 bolt---o SP o----bolts D
6 bolt---o o---bolts E
7 bolt---o SP o----bolts F
8 bolt ---o o---bolts G


I think it is the #1 Big bolt location pictured but I'm not sure
Thanks,
Mudd Minnow

[boats.net]

Here is the plug to use, the 60 and 70hp engines use a low pressure cooling system and may not show much or any pressure on gauge.
WaterPort60-70hp.JPG

[mudd minnow]

Thanks, I thought it was that one but I wasn't sure. Have a great day.

Mudd Minnow