Replace what other parts when replacing head gasket?

[mmaddox]

I have a Johnson 1969 40-hp electrostart outboard motor and am putting a new head gasket on it. What else do I need to replace when I put on a new headgasket?<br /><br />Is there anything I need to be careful to do or not to do?<br /><br />Thanks.

 

[wilde1j]

Re: Replace what other parts when replacing head gasket?

Make sure the head is flat (not warped). If motor overheating was cause of head gasket failure, the head may likely be warped, in which case it needs to be surfaced. See shop manual for details. Have you also removed the head cover?<br /><br />New gaskets go back on dry and fasteners should be tightened using a torque wrench to proper values.

 

[mmaddox]

Re: Replace what other parts when replacing head gasket?

Jim,<br /><br />I believe the head gasket gave way due to age and usage.<br /><br />What is the best way to tell if the head is warped?<br /><br />I've already removed the head, cleaned the surfaces, and am about to put the new head gasket on. I did not have the head resurfaced though.<br /><br />Mark

 

[ob]

Re: Replace what other parts when replacing head gasket?

You can use a good precision straightedge and a feeler guage and check several locations of the head surface from varying angles.Imperfectios and warpage should not exceed .002".

 

[mmaddox]

Re: Replace what other parts when replacing head gasket?

Thanks very much to both of you!