very little compression

[spider_man]

Banshee sho motor seems to have no compression. I can turn the crank by hand very easily. Yes the spark plug is in! There also seems to be a bit of a clunk near top dead center. Is this a sign of a bad big end or crank bearing? Would that also explain the loss of compression?
my mates blata rep has more compression..

[CarterRaceEngines]

I'd say you've shit a ring

[spider_man]

the bike still kicks over and vibrates a lot when you ride it...
im going to stip it tomorrow and put polini parts in it.
know any one in sydney with polini parts??
thanks spidey

[CarterRaceEngines]

We have a great selection of Polini parts wht do you need?

[spider_man]

what im after is:

polini race crank
Malossi piston & chromium ring kit

dats about it,if you know anything else that would make this motor a beast your input would be great..
thanks spidey

[gazza2003au]

hmm thats abit weird the bike still starts but u have no compression this could be a possability the piston has melted (on top) ran down the side and stuck your ring into the piston ive seen this a few times on my bikes and on my jetski or your ring could have popped out (as carter said) and squashed into the piston as for the clonking noise could be anything maybe a ring stuck on top of the piston hitting the head? what ever is wrong with it dont start or ride the bike strip it and have a look i say your top end is rat shit

[spider_man]

the ring, piston and crank look perfect..
does the banshee 49cc have less compression compared with a blata rep 39cc?
what should the squish be set at?
thanks spidey

[gazza2003au]

check the tension on the head bolts

[BoneGraft]

Is your spark plug tight?