My avenger phantom hybrid

[Soulfly]

Well got a short ride in not a goid one but it runs. I think that stripped head bolt caused a vacum leak I adjust the idle screw either to much or to little and it wanted to accelerate on its own and on a engine like that on a bicycle it was scary. Other than them head bolt hole being bad the crankcase is good and I really dont want to spend $139 on a phantom 85 crankcase so does anybody have any advice on fixing them head studs? If I go up in size what size and use what studs any help would be greatly appreciated. Thanks.

 

[GW's Motorized]

You could use helicoil and use the regular size head stud

 

[DieselTech]

Buy the long heli-coils you need for the cylinder studs you got.

Then make sure not to drill thru the bottom of the case stud boss/casting.

Then install the new heli-coil with some high temp loctite & then break the locking tab off of the heli-coil.

If the heli-coil is too long once you install it, then buff the remaining heli-coil off with a 3m scotch brite pad & a buffer/die grinder.

 

[Soulfly]

Thanks guys sounds good. I was of the understanding that Id have to go up in size with heiecoil. So I can stay at 8mm?

 

[GW's Motorized]

Thanks guys sounds good. I was of the understanding that Id have to go up in size with heiecoil. So I can stay at 8mm?

Yup, you tap for the next size up, and the heli coil takes up the space so you can thread your stud back in.

 

[Soulfly]

Yup, you tap for the next size up, and the heli coil takes up the space so you can thread your stud back in.

Thanks man.

 

[Soulfly]

Buy the long heli-coils you need for the cylinder studs you got.

Then make sure not to drill thru the bottom of the case stud boss/casting.

Then install the new heli-coil with some high temp loctite & then break the locking tab off of the heli-coil.

If the heli-coil is too long once you install it, then buff the remaining heli-coil off with a 3m scotch brite pad & a buffer/die grinder.

Thanks man.

 

[DAMIEN1307]

Thanks man.

I used this kit myself for this exact same problem...Worked fine and was able to stay using the M8 x 1.25 studs.

https://www.amazon.com/Highking-Tool-Compatible-Repairing-M8-1-25/dp/B07VVKSGK5

 

[ImpulseRocket]

Helicoil, or new cases. https://www.amazon.com/YD100-Bottom-Engine-Motorized-Bicycle/dp/B0BYZBFX1R
New cases are cheap, but it's basically a full rebuild to swap them out.

 

[Soulfly]

Well guyz, I pulled the cylinder and the piston was gouged rite thru the rings Ill get better pics tomorrow in the light my phones camera is crappy at first I thought Id got lucky for once in this but he$$ no and Ill get a pic of this tomorrow the cylinder was gouged rite at the bottom Im not sure if its junk now 90 sum dollars shot to he$$ Im not sure if Im going to replace it. I felt the power it had and was excited but Im not rich by no means and keep on making them d#@n Chinese money for garbage metal. IDK not feeling to good about it. Like I said Ill get better pics tomorrow and the cylinder.