Head stud replacement

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Peter16

New Member
Jun 24, 2012
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Australia
I am fitting a new top fire head to my HT engine. When unscrewing the head bolts of course each stud came out too. After some reading on here i have learnt the studs and acorn nuts are junk and need replacing. I just want to confirm that you can use fully threaded rods as the head studs. (as opposed to a bar with threaded tips)

while i have your attention what is your opinion on how the motor is running?
I have just finished the run in at 24:1 and put maybe one litre of 40:1 through it. It looks as though there may have been a leak.
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thanks guys
Peter
 
biknut

biknut

Well-Known Member
Sep 28, 2010
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All the stock cylinder studs I've seen were just fine. Theres nothing wrong with the head bolts either, but care must be taken so that the acorn nuts don't bottom out on the stud. If it does, add a washer or two.

Install the cylinder studs all the way into the block. They don't need much torque. 50 or 60 inch lbs should be plenty to seat them in the block, but a little more or less probably won't matter.
 
biknut

biknut

Well-Known Member
Sep 28, 2010
6,631
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Peter16 said:
i probably did mine to about 50 or 60 inch pounds, then i torqued the nuts to 140 iirc
Click to expand...
I think anywhere between 125, and 140 on the head nuts is good. I wouldn't go over 140. I doubt any of the stock 8 mm studs would have any problem with 140 ft lbs.
 
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Peter16

New Member
Jun 24, 2012
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Australia
the new head and gasket is leaking in about 3 spots. This probably explains why the bike was so gutless after i put the new one on.
 
biknut

biknut

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Sep 28, 2010
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Peter16 said:
the new head and gasket is leaking in about 3 spots. This probably explains why the bike was so gutless after i put the new one on.
Click to expand...
If that's the case, it's easy to get sand paper, and glass, and resurface the top of the cylinder, and the head. Don't go crazy on the head.

It shouldn't take excesive torque on the head bolts to seal the head.
 
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Peter16

New Member
Jun 24, 2012
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Australia
is there some sort of compound you can put on to aid in sealing? I find it odd it is only metal and no fibrous material like you find with most 2 stroke head gaskets.
 
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