Topic: aNother leaking head! -- The 750

[Pecantree]

Thanks for the reply's!

Cycle-x rocks, gaskets were ordered Monday morning and delivered this morning!
Waiting on service honda now.

Ron: I don't think the cam tower studs were ever removed from the head.
If you remove the sparkplugs, turn the head on its side and look thru the plug hole.
You can see the bottom of the cam stud. Helps to shine a light into the well from the top.
I put a piece of tissue on a brush and rub against the bottom of the stud. Tissue came out dry.
So I'm hesitant to pull them to put sealant on.

Mike: The gasket I got was the MLS. The gasket is a bit thicker than a regular gasket. Will this affect compression?
I'm leaving the base gasket undisturbed.

Mark: Sounds like you've had some come back with looser 6mm inner bolts. Fingers crossed that this is what the leak is coming from. That's why I've ordered new 6mm bolts. I'm planning to use blue loctite unless y'all think something else is better. The puck holes in the head are milled flat, not at an angle. Also the oil jet holes are 1.5mm deep and I got a reading on the used o-rings at 1.89mm. I'll look for the smaller o-rings for the assembly.

Lucky: I'll check the height on those. I've seen that mentioned on several other posts too.

Spent yesterday redoing the front forks and cleaning old oil off the engine.
Taking the grandkids to Kerrville for the folk festival this weekend. Gonna be hotter than camel snot. But they want to go. When I get back I'll post a pic of the MLS gasket and do a measurement compared to the regular gasket.

Again, Thanks for everybody's input.
Steve

[MCRider]

Steve: You read me correctly. Certainly if they are dry and have never been disturbed, leave them alone.

[Pecantree]

A little update on this.
This project was finished a while back but I want to leave a complete record and how the problem was solved.


Opened up the box from Cycle-x and pulled out the head gasket.
Hmmmm!
This aint gonna work.

Called Cycle-x at 3pm on a friday, Jim got a new gasket in shipment that day. Thanks!
After the holiday weekend waited for new nuts and bolts from service honda.
The new 6mm center bolts are now without the JIS in the center. Have to use a thinned deep socket to install the 2 center bolts.


Also took off a smidgen from the 8 dowels, Make sure there was plenty of room on the head for gasket compression.
Top row is pre-smidged!

New MLS gasket arrived. But From reading other posts I realized I needed a milled head and cylinder to use it.
Head and cylinder were not processed from build. They are flat, measure at  .002 to .003 gap under a straight edge.
Stashed the MLS for the next engine and pulled out the backup gasket from a previous gasket kit.

After cleaning the old gaskets off I found a divot in the head surface  and the mating surface of the left side camshaft carriage.
I didn't picture it but it was located by the second of the 6 pucks. The indentation was a spiral shape about 3/32" across.  I think I picked up a metal shaving during the first rebuild, probably stuck to the gasket. This kept the head and camshaft carrier just gapped enough to let one or more of the pucks to fail.

Everything has been together now for a while and seems to be holding steady.
Have to give kudos to brandEn's thread.
http://forums.sohc4.net/index.php?topic=107040.0

TL;DR.   Debris kept mating surfaces apart, caused oil Leak

[krusty]

I have a leak that sits on my top fins. I'm keeping an eye on this thread!

Ditto that with my 750F1