Low compression

[CRAZY-SHEE!]

ok.. ive been working on my cousins quad all day. (banshee) and it runs like shit... my sisters blaster with only v force reeds and an fmf pipe kicks this things ass out of the water. his banshee is all stock. i mean.. it really is running like shit.. its actuing weird.. like sometimes itll have a good top end.. like a lgihtswitch effect.. but most of the time he got nowhere in the powerband area.. sometimes its difficult for it just to get throguh all the gears and it has like.. noooooo throttle response... like it takes 6-7 seconds before it actually starts to go anywhere and get that lightswitch effect... and sometimes itll work on the right pipe.. sometimes the left.. and his left pipe is sometimes shooting unignited gas/sludge. Now.. i asked him a little bit about it.. its an 89 and its on its original top end >_> soo... 17 year old top end.. better look into this.. and he also says.. that the person before him put new pistons in it, because one BROKE APART, SMASHED AROUND IN THE ENGINE, but never bored it because he said it didnt look liek the cylinders had much damage. O_O. so i take off his cylinders.. they are F***ED UP. The head, has dents in it. I put eveything back together.. and it has a compression test of... 50 . Well thats depressing. lol so would all these problems be cause by this low compreion? btw he has a hole in his left exaust pipe in the expansion chamber. and will the head be ok or do i need to order him a new one? and his carbs have 160 mains in them. not sure if this could be a arb problem.

Edited April 15, 2007 by CRAZY-SHEE!

[bansheeyfz]

well stock main jets are 200-220 depending on elevation

[CRAZY-SHEE!]

u serious? i live in az.. he says he never touched the carbs.. i think were at like 1500 or something.. that or sea level...

[CRAZY-SHEE!]

comon somebody gimme some advice here.

[mpbanshee]

OK, here goes. First, take or send the jugs and head to a reputable shop, and have them inspected to see how much they need to be bored to clean them up. Next, order the appropriate size top end kit (pistons, rings, bearing, and gaskets). Have the jugs bored and honed for the new pistons, and the head resurfaced and install the new top end. Then, clean the carbs out really thouroughly and set them back to stock jetting (200 mains, 25 pilots, needle clip on middle groove, and 2 turns out on the air screws). Finally, the hole in the expansion chamber needs to be fixed. This is where two strokes make their power. It should run much better after you do this stuff... Once you are done, you may need to fine tune the jetting.