1990 90hp Lower unit bolt torque

[sjaltobelli]

Does any one know how much to torque the bolts that hold on the lower unit? I have a 90 hp 1990 force engine. There are 6 bolts visible and one hidden under the trim tab. Also, how to I index the trim tab? Is it just guess and check? Thanks for any help.

 

[a1machinista1]

Re: 1990 90hp Lower unit bolt torque

I cant find a factory spec for that either. What sealant are you going to use? Do you have a picture of your powerhead?? I need to see where a few things go. Those are 3/8th bolts arent they?? If so I would go 25 lbs with a thread sealant... 32 lbs if you are just going to oil the threads (not sure what it calls for)

 

[Frank Acampora]

Re: 1990 90hp Lower unit bolt torque

Standard torque for a 5/16 X 18 bolt (1/2 inch head) is 160 INCH pounds. Use inch pounds as it is more accurate than foot pounds. Note that the grade 8 head bolts are the same size and the aluminum block will tolerater 220-230 inch pounds. However, the lower unit bolts are stainless and NOT grade 8 so I would not trust them that high.

 

[a1machinista1]

Re: 1990 90hp Lower unit bolt torque

Sounds good to me