Milky spark plugs

[Bpace1985]

I have a 1997 75 hp force it started fowling spark plugs and I noticed there was white milky stuff on #1 and realy bad on #2 plugs so I pulled the head off and the same stuff was all over the inside of the head and the gasket was fried. could this be just the head gasket or is there other things I need to look for
Thanks

 

[pnwboat]

Re: Milky spark plugs

Either head gasket or exhaust cover gaskets are the most common culprit. Replace the head gasket and test. If no more milky stuff you're good to go. If still milky, then go on to the exhaust cover. Use caution when removing the exhaust cover bolts. They often get a little corrosion and kind of seize up. Use liberal amounts of CRC, PB Blaster, WD-40 or whatever. Tap the head lightly and maybe even apply a little heat. Be patient and you can avoid having to drill a broken bolt out.

 

[Jiggz]

Re: Milky spark plugs

X1 with the head gasket. Make sure you follow proper torque sequence and steps. If not sure how ask.

 

[Bpace1985]

Re: Milky spark plugs

Thanks and that would be my next question how do I put the heads back on

 

[pnwboat]

Re: Milky spark plugs

The 75HP motors are slightly different from the other motors.

Head bolt torque sequence, note the serial number notation at the bottom of the page.




Head bolt torque values, note that they are in inch pounds and that the 75HP has a special notation at the bottom of the page. It uses the "Torque and turn method".

 

[Bpace1985]

Re: Milky spark plugs

Ok my serial # is oe250059 do I us the same sequence or a different one and thanks for the info i did not know all of this

 

[Jiggz]

Re: Milky spark plugs

Based on your serial number you will use the "Torque and turn method" discussed above. However, your sequence should be the standard spiral sequence method (shown below except this is for a 4 cylinder engine but the sequencing should be the same. The one posted above is for 98-99 75HP with serial number OR345000 and above while yours is below or lower than this.

One additional thing is to use 2 or 3 steps torquing. What that means is that you do not start torquing each bolt to its final torque of 120 in-lb instead you take it in steps. For example with a 2 step torquing, you will initially start torquing all bolts up to 60 in-lb and then start all over again and torque them to 120 in-lb. And then double check all bolts with 120 in-lb of torque making sure none will turn more than 1/8 of a turn. If any one bolt turns more than 1/8 then you will check all bolts again starting from the first one until none will turn more than 1/8 of a turn. And then you can finally do the "turn method" which means you will add an additional 1/4 turn to each bolt and you are done, NO NEED TO DOUBLE CHECK AFTER THIS STEP.

And after your first run on the engine in the water (with engine reaching operating temp), after it cools down you will need to re-torque again. Thereafter you should be good to go.