Torque Specs on Exhaust Extension Plate and Power Head Mounting Bolts Mercury V6

[runninfarmer]

Hi All, anyone know the torque specs for the exhaust extension plate on a 1984 Mercury Black Max 150? There are 3 bolts that use a 9/16 socket, and two middle bolts that use a 1/2” socket. I’ve looked my manual up and down and doesn’t show them. Also doesn’t show the torque specs and sequence for the 10 power head studs, which are also 9/16” socket. Thanks in advance! Here’s a pic:

 

[Dukedog]

tha two in tha middle, (5/16) a little at a time, are 25 ft. lbs.... 3 (3/8) bigger ones on tha rear outside are 50 ft. lbs... tha 10 (9/16) nuts on tha studs are (my version) tight as ya can get 'em with a 6" 9/16 box end (sequenced, back and forth across clockwise, jus like a head)................. merc calls for 20 ft. lbs.....

did you pull any of tha 10 studs?

 

[runninfarmer]

tha two in tha middle, (5/16) a little at a time, are 25 ft. lbs.... 3 (3/8) bigger ones on tha rear outside are 50 ft. lbs... tha 10 (9/16) nuts on tha studs are (my version) tight as ya can get 'em with a 6" 9/16 box end (sequenced, back and forth across clockwise, jus like a head)................. merc calls for 20 ft. lbs.....

did you pull any of tha 10 studs?

Uh oh, I might be a little low on the 5/16 ones. I ended up going off the spec for head cover (same size bolts) which was 150 in-lb or 12.5 ft-lbs. Do you think 12.5 ft-lbs is enough on those? I can lift powerhead back up, but I don’t want to risk ruining my gaskets. Thanks again for the help!

I also got lucky and none of the studs came out.

 

[Dukedog]

you should be able ta lift it enough ta put a little more on 'em jus in case.. a short socket ona torque wrench should go under it maybe.. they probably don't need much more.... jus be careful, those two tend ta break easily........

 

[runninfarmer]

Well I lifted her up and put 25 on the middle 2 and 50 on the back 3. I took pics of the gasket, it got some oil residue on a corner but hopefully it’s ok. I rewiped the powerhead mating surface and spot checked the gasket.

 

[Dukedog]