Z80....Not So Good

Discussion in '2-Stroke Engines' started by Dave C, Feb 28, 2011.

  1. Dave C

    Dave C Member

    I'm beginning to think this motor is a junk pile abortion.

    Pirate Cycle intake bolts too long, had to cut them about 3/16ths shorter.

    SBP head studs don't fit, lower part of stock stud fine threads, upper part coarse. Undersized by enough that the SBP stud will not thread in more that 1 turn. Fixed by thread tap to the correct size.

    Jug to case gasket is different that transfer port opening. It seals but just barely.

    After taking the clutch cover off to install SBP dampener material there seemed to be a *lot* of black rubbery :poop: inside the cover so on the needed parts list I have goes new clutch pads and a puller.

    Next motor I get will probably be a Grubee. They seem to care what is done to their branded stuff better than anyone else, to the point of traveling to China to see the factory. Maybe he impressed the Chinese by going to see for himself instead of buying a shipping container full of whatever:whistling:

  2. Dave C

    Dave C Member

    Ok, turns out they just don't tap to the bottom of the hole, only about halfway. The SBP head studs fit perfectly in their newly tapped holes and their in deeper than the stock ones went.

    Same holds true for the intake and exaust holes, their only tapped in about half. Harbor Freight has a carbon steel tap set that's just under $12. MUCH better than their older sets.

    Tap out the holes and your good to go:helmet:
    Last edited: Mar 3, 2011
  3. retromike3

    retromike3 Member

    Who made the kit?

    Just for information, Who make the kit you are having problems with?

  4. Dave C

    Dave C Member

    boy go fast and I'd say any advertized Z80 motors, I can't say they'd be made any different.:rolleyes7:
  5. retromike3

    retromike3 Member

    Boy Wont Go

    My sympathies go with you. The first kit I bought was a Boy Go Fast kit and that was a disaster. I did on the other hand get to find out the inner workings of these engines. When the next item failed I found out more. I eventually had to replace all of the parts of the kit Now I can take apart the whole motor and reassemble it without to much trouble.

    Boy Go Fast Was on Ebay and it was really cheep and it did work for a while so it was not a total loss. I got a class in two stroke engines and all it cast me was about a hundred and thirty bucks.