low compression

Discussion in 'Battle Scooters' started by JG5, Jan 17, 2010.

  1. JG5

    JG5 Adventurer

    Jan 10, 2010
    i have a 1990 yamaha that i recently bought i just checked the compression and it only has about 60psi, i took the cylinder off and checked it for scratches and stuff, the piston seems as good as new except for a small bit of carbon build up on the top the gaskets look fine, i put it all together again and sealed the gaskets but it still only reads about 63psi. i added a bit of oil to it but it doesnt make a difference. is there a way to fix this? its only -5 Celsius would that make a difference?