49cc head gasket, torque?

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jmperry55

New Member
Dec 3, 2010
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Fort Myers, Florida
I built a 49cc, w/NTTC carb for my Grandson. For reasons I won't go into, he removed the head and put it back on. I found a problem with the spark plug cap which I can fix. But can anyone tell me what to torque the head bolts to? And will I need to replace the head gasket or can it be reused? Given what he has done, anything else I should be aware of or watch out for?
Don't know what I would do for answers without the kind and helpful folks on this forum.:-||
 

bigbutterbean

Active Member
Jan 31, 2011
2,417
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38
Lebanon, PA
Your manual should say what to torque the head bolts to. Honestly, I never used a torque wrench to tighten my head bolts, and I never had a problem. What I did was go in an x pattern and tighten each one a little at a time, repeating the same pattern until all four bolts were as tight as they would go. You will find when you torque them that they won't go past the recommended amount of torque anyway. I know that from the one time I did use a torque wrench. Just loosen all of them, and with your fingers, tighten them until they just touch the head. After that, use a socket wrench and repeat the x pattern. The gasket is reusable. If you want, you can replace it with the spare that came in the kit, but the one that's on it should be fine.
 

Al.Fisherman

New Member
Sep 9, 2009
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Calera, Alabama
The manual misses that part, at least in every one I've read.

To answer your question on torque and not a WAG.. here are the recommend torque. I got these online using steel studs in aluminum. Have never blown a gasket in 5 engines, have never stripped a stud hole or stud.

8mm torques to 150 to 204 INCH POUNDS
6mm torques to 50 to 60 INCH POUNDS.
Some engines use a 6mm head studs, I have one.

Most likely the head wasn't torqued to those specifications from the factory. If not use the head gasket and torque to above. I have used head gaskets more then once without leaking. Before you install the head, mill it. I have NEVER seen a true head. Using a piece of glass and 280 sand paper, sand gasket surface. Only remove what is necessary. The sanded surfaces will stick out apart from non sanded surfaces.
 
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jmperry55

New Member
Dec 3, 2010
21
0
0
Fort Myers, Florida
The manual misses that part, at least in every one I've read.

To answer your question on torque and not a WAG.. here are the recommend torque. I got these online using steel studs in aluminum. Have never blown a gasket in 5 engines, have never stripped a stud hole or stud.

8mm torques to 150 to 204 INCH POUNDS
6mm torques to 50 to 60 INCH POUNDS.
Some engines use a 6mm head studs, I have one.

Most likely the head wasn't torqued to those specifications from the factory. If not use the head gasket and torque to above. I have used head gaskets more then once without leaking. Before you install the head, mill it. I have NEVER seen a true head. Using a piece of glass and 280 sand paper, sand gasket surface. Only remove what is necessary. The sanded surfaces will stick out apart from non sanded surfaces.
Yeah, not in either of my PDF files that serve as manuals. Thanks for the info.
 

dmb

Active Member
Dec 4, 2010
1,354
3
36
lakewood ca
crown nuts could pull the studs. i use flange nuts or you could use nuts and washers. don't use lock washers. and re torque after a few heat cycles. good luck