Reply To: No spark gt125r 06

[♠️ M77]

I think its time to rebuild the front cylinder

At minimum, you want around 125 PSI

Hyosung says the limit is 110 psi hot  and  healthy range is  140 – 175 psi

Here is a cheap front barrel and piston, it should be OK
https://www.ebay.co.uk/itm/256864818680

And here is a spare one
https://www.ebay.co.uk/itm/255751060887

I have confidence that either of the above will finally get the bike running.

Ofcourse make sure to get new gaskets you see on this shop

Rear is already at the limit of 110 psi but… If you have to do the rear, then check these out
https://www.ebay.co.uk/itm/256513929819

Hyosung Korea isn’t making new pistons for carb 125cc  or rings.

I am slowly researching and soon will test custom piston rings off another bike that may fit our bikes.    If you just want piston rings,   then i think you should email me , but stock is rare now.

This is why you can’t idle, the compression is too low.