Cylinder and head studs

[graggy]

How many times can you take the head off a 66/80 2 cycle engine. Do the studs have to be replaced after so many times because of stretch or something?

 

[cloakedvillain]

Studs do stretch but because of the low torque spec it should be fine as long as the studs are kept to spec.

 

[GW's Motorized]

The studs dont usually stretch on these, it is usually the aluminum that does.

 

[DAMIEN1307]

It is the threads that expand and contract on both the stud as well as the threads on the recess...This is the primary reason why you only tighten/retorque when motor is totally cold, never when warm or hot as you risk stripping the threads right out.

 

[A. Thomas]

It is the threads that expand and contract on both the stud as well as the threads on the recess...This is the primary reason why you only tighten/retorque when motor is totally cold, never when warm or hot as you risk stripping the threads right out.

Damien, where can you find torque specs for these engines? Are they all different for different models?

 

[DAMIEN1307]

Damien, where can you find torque specs for these engines? Are they all different for different models?

Right here...lol.

Stripped head bolt studs

I bought a bikeberry 48cc kit 2-3 years ago and have had it running off/on. Recently I noticed that my head area is leaking alot of oil and compression is sucky. One of the head bolts is stripped. I don't know exactly what size I need. Does anyone know, for sure, exactly what size bolt I need...

motoredbikes.com

 

[ImpulseRocket]

Even with chinesium steel these studs are nowhere near yield point at 15ft-lbs

 

[A. Thomas]

That’s a relief. I read about stripping them and it does make a bit nervous.

 

[Wrench]

That’s a relief. I read about stripping them and it does make a bit nervous.

It's not the studs ya gotta worry about. It's the aluminum threads in the case that will pull out

 

[A. Thomas]

It's not the studs ya gotta worry about. It's the aluminum threads in the case that will pull out