ryan954 Posted November 18, 2014 Report Share Posted November 18, 2014 Hey guys im kind of new to the banshee world. So i bought a banshee. It ran fine for a while then i let my cousin borrow it and he blew the piston (wont do that again).so i just replaced the topend on it. I got it bored to 65.5. I put wisco 795 pistons in it and i got a coolhead from jeff over at fastracing. I did a leak down test and it took 2 hours for the gauge to go from 6 psi to 0 psi. So then i did a compression test. On the left cylinder i got 125 psi and on the right side i got 145 psi. My question is why do i have differnt readings between the 2 cylinders. I haven't even started the bike up yet. Mods noss coolhead 23cc domes 4mil 115 vitos 65.5 pistons v3 reeds Mikuni 34mm carbs Cpi pipes year 97 the bike has some port work but cant tell what kind of port work it has. The previous owner couldnt tell me anything about the bike Im in south florida so im at sea level Quote Link to comment Share on other sites More sharing options...
ryan954 Posted November 18, 2014 Author Report Share Posted November 18, 2014 I DOUBLED CHECKED THE ALL OF THE O RINGS ON THE COOLHEAD. THEY ARE STILL IN THE RIGHT PLACES. I TORQUED THE HEAD TO 20 FOOT POUNDS. Quote Link to comment Share on other sites More sharing options...
RadarRacing Posted November 18, 2014 Report Share Posted November 18, 2014 On a non broken in motor a compression test is not going to necessarily read correctly. Check squish clearance, if it read differently after a few good heat cycles then there might be an issue but otherwise it should be fine. Since you are new to this you might check to see if the low reading side or both for that matter have the pistons installed correctly with the windows on the skirt of the piston facing the intake/reeds and NOT the exhaust. Many make that mistake. Quote Link to comment Share on other sites More sharing options...
sheerider1026 Posted November 18, 2014 Report Share Posted November 18, 2014 Maybe it's a hack port job and someone has one exhaust port higher than the other? I am see the readings being of a little until it's broken in. But not THaT far off Quote Link to comment Share on other sites More sharing options...
ryan954 Posted November 18, 2014 Author Report Share Posted November 18, 2014 Ok the pistons are in the right way. So im going to start her up and see what happens. Ill do another compression test after its broken in. Ill post the new numbers. Thanks for the help Quote Link to comment Share on other sites More sharing options...
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