91 40HP johnson power head torquing

[blgrams]

I am rebuilding the power head for my 40HP johnson and I have both the seloc and clymer manuals. my question is about torque values and order for crankcase to block bolts. There are 6 larger bolts that are on either side of the berrings and 8 smaller ones around the "shell". It appears ( according to the seloc apendix)that I torque the larger ones to 18-20 ft lb and the smaller ones to 60-80 in lb. the clymer seems to indicate that all go to 60-80 in lb. I intuitively think that I should do the large ones around the berrings completely first alternating the pattern from the center then do the smaller "shell" ones alternating the pattern from the center.<br /><br />any thoughts?

 

[Hooty]

Re: 91 40HP johnson power head torquing

Yep, sounds like the hot ticket ta me. Start with the center bolts and tighten in a circular pattern and in three steps. i.e. First time tighten to 14ft/lbs. Second time 17ft/lbs. Third time 20ft/lbs.<br /><br />c/6<br />Hooty

 

[blgrams]

Re: 91 40HP johnson power head torquing

how do you feel about re-using connecting rod bolts during rebuild?

 

[Hooty]

Re: 91 40HP johnson power head torquing

I don't do it. First, you don't know how tight they were tightened when they were installed so you don't know if they're stretched or not. Next, you don't know if they were new when installed or not and thirdly, they're a key component and it's just good practice to replace 'em. <br /><br />c/6<br />Hooty

 

[Walker]

Re: 91 40HP johnson power head torquing

And forth, they don't cost that much.

 

[blgrams]

Re: 91 40HP johnson power head torquing

thats what I thought unfortunatly it will cost me another week without my motor in what is already a short fishing season in the great north. your reasons are much better than my "just in case". especially the how many times have they already been re-used and possibly over torqued.<br /><br />much appreciated!!!<br /><br />Minnesota: many are cold but few are frozen!