xrvic Posted December 15, 2004 I found a big bore xr 440 kit . It is rated at 12.5 to 1 compression ratio.. Has any one done this mod at this ratio ? any problems ? Thanks! Share this post Link to post Share on other sites
CoreyClough Posted December 15, 2004 You really don't need the high compression piston, unless you're all out racing it. Share this post Link to post Share on other sites
SidewinderX Posted December 15, 2004 I found a big bore xr 440 kit . It is rated at 12.5 to 1 compression ratio.. Has any one done this mod at this ratio ? any problems ? Thanks! It will be fine at 12.5 : 1. That is what the CRF's and yzf's are running stock. Do not shave your jug much if you are installing a new sleeve because this will raise it even more. I was close to 13.5 - 14 :1 ratio and needed to run 100 octane or higher in mine. That gets to be real expensive and a real pain to find. Share this post Link to post Share on other sites
Rockjockey Posted December 15, 2004 I went with the 11.5 to 1 and it works awesome for me.I also added Head porting,Black Diamond valves,Hotcam,Edelbrock pumper,Hinson clutch,Magura hydraulic clutch assembly,UNI filter,White Bros. header & E-2 silencer.Made the old 400 a real torque monster. 😢 Share this post Link to post Share on other sites
e4dragongunner Posted December 15, 2004 RockJockey tell me more about your 440 .... Did you loose any thing down low going to the hot cam.... How do you like the Hydrolic clutch????? Share this post Link to post Share on other sites
Rockjockey Posted December 15, 2004 Gained alot down low,does not make alot of power on top,you must short shift to use the power effectively, The hydraulic clutch is buttery, one finger operation.The pipe seems to have brought more midrange power to it. 😢 Share this post Link to post Share on other sites
KEVXR416 Posted December 16, 2004 Gained alot down low,does not make alot of power on top,you must short shift to use the power effectively, The hydraulic clutch is buttery, one finger operation.The pipe seems to have brought more midrange power to it. 😢 How much was it and how was the install thanks in advance 😢 Share this post Link to post Share on other sites
KEVXR416 Posted December 16, 2004 The hyd. clutch I mean,...........sorry 😢 Share this post Link to post Share on other sites
Rockjockey Posted December 16, 2004 Simple install,just route the hose exactly as you remove the cable and you'll be fine.I bought mine from SRC inc for $239.95 they customize the magura kit to fit the XR because Magura does not make one for the bike,they want to sell you one for a 4 wheeler and tell you to modify it somehow.I ordered it and had it in hand in three days.I think it came from Kentucky. Share this post Link to post Share on other sites
