Couldn't find a simple answer. Can someone enlighten me?

Hello Moto!

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I looked for a straight forward answer to a pretty simple question but was having trouble finding one.

I would just like to know how tight should I torque the head bolts on my 66cc engine?

I've heard 12 and also 15 on the torque wrench but not sure what is optimal? Honestly I got to 12 and became fearful that I was gonna strip something out so I stopped. Any suggestions?

I just gained access to the forum and this is my first post outside of the introduction. So thanks again for access and I look forward to being a part of this forum!
 
When you say 12, 13, 15, I take it you're talking ft/lbs?

That sounds like a bit too much. Particularly 15 ft/lbs. But 12 ft/lbs. sounds pretty high, too. I've been told to go with 120 inch/lb. Even that feels a bit too high to me. When I'm getting those bolts torqued in that range it feels like I'm close to stripping those threads.

So I go with 110 inch/lb. I do it in two steps as well. I'll torque all four to about 70 inch/lb or so and then I'll torque all four the rest of the way.
 
Yes I mean ft/lbs. Those are the only marks on my trusty torque wrench lol. How do you get from inch/lb to ft/lb? If I had an educated guess maybe you just divide by 12?

Yes I must agree with you on the feeling of possibly stripping the threads up in that range. Like I said at 12 ft/lbs it felt like I was tempting fate so I stopped. It has been said that a wise man senses danger and turns back, a foolish man senses danger and keeps going lol.

Anyways, Thanks.
 
One day the studs felt like thay were spinning and thay come straight out the domed nuts head
 
The weakest part is where the stud threads into the aluminum.
So while 15ft/lbs is ok for the stud and nut, it will pull the threads out of the aluminum.
This is a pretty good chart:
METRIC.jpg

Better if you lube your threads. Loctite is a lube too.
There are a huge number of factors involved, but these are safe values.
Steve
 
i go with 12 maximum... anything higher is not nessisarry at all and could cause issues with the soft aluminum head bolts stripping out...
 
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