First ride on single speed I built and it keeps jilting when I the pedal hard

softly pedaling = no problems, soon as i start pedaling hard it starts jilting. any ideas on how to avoid this

explane "jilting"??

http://www.youtube.com/watch?v=iN45OjB-cCU

when im pedaling it feels like its missing a tooth on the cog and shifting forward

i got jilted once, wont happen again I can tell you.

is it single speed (free) or fixed?

sounds like the inside pawls might be going, replace freewheel

Do the cranks wobble left to right at all?

does it shift back again or keep shifting forwards?

sounds like the inside pawls might be going, replace freewheel

This one, especially if its dicta ss freewheel or similar cassette freehub like quando or promax

the free wheel is brand new

Old chain?

the free wheel is brand new

What size? 1/8" or 3/32"

and what size chain are you using with it?

could be the cranks are moving on the spindles. as suggested by jonlubi

i dont know anything about ratios, its a 1/8 chain and a bmx cog

speak to emoxfag?

i dont know anything about ratios, its a 1/8 chain and a bmx cog

slack chain?

If your chainring is really really worn out, and your chainline is terrible. There is a chance you'd get slip there, the chain might jump off under pressure.

photos would be helpful

it is a bit slack, but cant remove any more links, what about - 1 + 1/2

http://www.flickr.com/photos/40612430@N08/3731438001/

http://www.flickr.com/photos/40612430@N08/3731438091/in/photostream/

Slack chain!

that chain needs to be much shorter. this is the reason for your jilting.

OSCC take at least a link out!

Also, can you take a photo from just behind the cog looking down the chain towards your chainring? It should be near enough a dead straight line, from the cog to the chainring.

You can easily take a link out - The dropouts are long enough.