80/66cc Cylinder jug

Discussion in '2-Stroke Engines' started by adrian101, Jul 30, 2011.

  1. adrian101

    adrian101 Member

    Hi guy,

    I have a 66cc F80b engine which i had a striped hole where the muffler studs goes into, about 3 weeks ago i drilled the hole out, re tapped it and put a dab of JD weld on a new stud before fitting it into the new hole. it had worked perfect until i heard a snap yesterday while riding.

    So now i have a snapped stud in the cylinder jug and i have no way of getting it out. so its looks like i will need to buy a new cylinder jug and so on and so forth lol

    My question is, If i buy a new cylinder jug do i have to buy a new piston including the rings. Then run/break it in again?

    Thanks for reading!

  2. motorpsycho

    motorpsycho Active Member

    i would definitly get new rings for a new jug.
    The old rings are worn to the old jug and if you put the old rings in the new jug, it will probably wear the cylinder funny.
    normally any time you have a new (bored, honed or brand new) cylinder, you want to put new rings in it so they can seat and wear the same.
  3. Al.Fisherman

    Al.Fisherman Active Member

    Let me back up to your original problem...Stud broken off. Have you attempted to drill a small (just under thread size), and use a easy out? The JB Weld is not going to hold and with some heat it will release. Other then that..answered above.
  4. HeadSmess

    HeadSmess Well-Known Member

    theres even a new variety of eziout that doesnt require a hole to be drilled! looks just like a left handed tek screw :) drillls its owwwwwn hole.

    for the guy that snaps HEEEEAPs of studs and is too lazy to change tools?

    or theres "spark eroders" they are all you can use if you had snapped a tap in the hole :) but at $3000 for a basic model...i think you want another option :jester:

    yeah. change rings. then again, if youre stingey and the previous cylinder hasnt had much use yet... leave them? :)
  5. Al.Fisherman

    Al.Fisherman Active Member

    I believe what you are referring (I kid you not) a left hand drill bit...but as you stated..you still need to drill the hole. Now with the fact that JB Weld was used a easy out may be needed. Also some heat needs to be applied to the case area. I hand torch should accomplish this. Cold, with the JB Weld, it's going to be hard to do it.
    Last edited: Jul 31, 2011
  6. adrian101

    adrian101 Member

    hi guys, i got the broken stud out with a easy out. Took around an hour due to the JB weld.. lol I have drilled the hole a little to prep it for re tapping, Have to making the thread "8 M" in size. I have to also mod the exhaust hole and gasket and find a 8M stud with a nut. Wish i didn't have to make the hole that big but its the best i could do.

    Thanks for the help.
  7. Al.Fisherman

    Al.Fisherman Active Member

    Did you need to use any heat to soften the JB Weld so it would release before extracting the stud?
  8. FelipeCobu

    FelipeCobu Member

    Maybe you can have it welded then re drilled and re-tapped.

    But I don't know how expensive it is around there cause I live in Brazil.

    You can also use HTS 2000 aluminium repair.
  9. Al.Fisherman

    Al.Fisherman Active Member

    In MOST cases, the cost of repairing (outside yourself) will exceed the cost of the cylinder itself. Welders usually charge a 1 hour minimum.
  10. adrian101

    adrian101 Member

    Yeah i used a heat shrink gun, after each 5 to 6 minutes of use, i tried to remove the broken stud. after the 12th time it decided to come out.
  11. Al.Fisherman

    Al.Fisherman Active Member

    Let this be a lesson...JB Weld will release when the engine gets HOT.