30hp 1988 - Cylinder head replacement

[jasper60103]

Got myself a J30TELCCE (1988). The excitement quickly wore off though.
I stripped the top spark plug hole! Anyway after several days of kicking myself I decided to bite the bullet and replace the cylinder head. After I got the head off this evening I discovered how I stripped the spark plug hole. The compression tester adapter was too long and hit the top of the cylinder head as you can see in the pic. As a result, the threads on the adapter were buggered from striking the cylinder head. When I unscrewed the adapter, it ruined the threads on the spark plug hole.

So my first question is should I try to repair the ding on the top of the cylinder head or does it matter?

Also, I want to clean up the tops of the cylinder heads while I have it open. What should I use?

And does anyone know the torque spec for the cylinder head bolts?

Thanks,
jasper

 

[marinemech1]

Re: 30hp 1988 - Cylinder head replacement

You may be able to salvage head using a Heli-coil repair kit. If the piston has been damaged(gouged) try to get the rough edges off it. Too clean piston tops I would use engine tuner...although I hear good things about Sea foam.
Wayne

 

[marinemech1]

Re: 30hp 1988 - Cylinder head replacement

P.S. use gasket sealing compound on new head gasket even if gasket says do not use sealer.
Wayne

 

[bktheking]

Re: 30hp 1988 - Cylinder head replacement

That's the piston, not the head and as long as it didn't go through the piston you should be ok. PM me your email address and i'll send you the torque diagram. Once you get it back together do a seafoam decarb to clean it up.

 

[jasper60103]

Re: 30hp 1988 - Cylinder head replacement

marinemech, bk:

oops, yes it's the piston head.
Thanks for the tip. No, fortunately it didn't punch through.

marinemech:
I looked at heli-coil repair kit. It would be cheaper, but I figured that would be best for someone more experienced than myself.
-jasper

 

[torbjorn]

Re: 30hp 1988 - Cylinder head replacement

Got myself a J30TELCCE (1988). The excitement quickly wore off though.
I stripped the top spark plug hole! Anyway after several days of kicking myself I decided to bite the bullet and replace the cylinder head. After I got the head off this evening I discovered how I stripped the spark plug hole. The compression tester adapter was too long and hit the top of the cylinder head as you can see in the pic. As a result, the threads on the adapter were buggered from striking the cylinder head. When I unscrewed the adapter, it ruined the threads on the spark plug hole.

So my first question is should I try to repair the ding on the top of the cylinder head or does it matter?

Also, I want to clean up the tops of the cylinder heads while I have it open. What should I use?

And does anyone know the torque spec for the cylinder head bolts?

Thanks,
jasper

Heli-coiling is easy. Run the piston to tdc and scrape the carbon deposits off the crown. Smooth any sharp edges in the gouge flat with sandpaper, otherwise don't worry about the gouge. Also, carefully scrape the cylinder head and tops of cylinders free of any deposits. Be certain not to use any gasket sealing compound with the new head gasket, simply apply some axle or Triple Guard grease to both sides of the metal rings. That was the advice of OMC Service, and that advice is good. I've always used it, and have had no problem. Extremely important, you must also follow the advised pattern in torquing the bolts, and torque them down a little at a time, not all at once.

 

[jasper60103]

Re: 30hp 1988 - Cylinder head replacement

Update. I found a replacement cylinder head and need to refinish the gasket surface.

Anyone know where I can find No. 180 Emery cloth? Can I buy in hardware stores? I imagine I need a good size sheet to do the figure trick.

 

[mikesea]

Re: 30hp 1988 - Cylinder head replacement

Go to a tile guy and see if he has a broken piece of MARBLE,wrap it with the emery.I use heavier,100 grit,if you can mount the head in a jig ir vise ,your best that way

 

[jasper60103]

Re: 30hp 1988 - Cylinder head replacement

I decided to repair my cylinder head. I did the save-a-thread repair on the bad spark plug hole and I cleaned-up my cylinder head and cover. Btw, the sand paper trick on a plane of glass works great for the cylinder head. Things are looking good. I bought a new tstat too.

One thing I noticed as I was getting ready to button things up is a hole is plugged on the head? Looks like it could be factory. Is this right? Feels like a piece of plastic...

cleaned-up the cylinder head and cover:

 

[flathunter]

Re: 30hp 1988 - Cylinder head replacement

I did the same thing to mine. I got the helicoil done for $20 instead of buying a new one. Can anyone post up the torque spec and sequence? Thanks in advance....

 

[bktheking]

Re: 30hp 1988 - Cylinder head replacement

Pm'd ya!

 

[jasper60103]

Re: 30hp 1988 - Cylinder head replacement

Just wanted to follow up and say fixing the stripped spark plug hole with the
Save-a-thread repair kit was a success. Also, I flushed the cooling system while I had the head off. Installed a new head gasket, thermostat, head cover gasket. The motor is running great now...

http://www.youtube.com/watch?v=wd5TOTrxFSs