overheating lc 50

[fomospede]

my son races xc as i do ,what i have is a stage 6 cyl. clutch and running no glycol with 50-50 redline water wetter and water, the radiator is clean and unobstructed and at slow speeds and or bottle necks (not moving at all), it will start getting hot. while practicing he keeps it moving and is not an issue .i see an oversize radiator hi flow impellars do either one work or any other ideas!!!!! thanks guys you all have good ideas and we appreciate your input

[Logan #34's Dad]

The Larger radiator will definately help for sure. I've got one on our 90 and I don't need the overflow (expansion) bottle and it stays with-in temp.
As far as the impellar, they are only a copy of the junk plastic one that comes stock. I'd recommend one because if the plastic one fails, you'll never know until it is too late.
The XFR Bumper with the air shrouds has to help too.
Call Justin at MaxRPM and he can get you everything you need.

[rmuscle]

have u checked to see if ur impellar is even still intact . we went through 4 last year and i finaly put an aluminum one in and have not had an issue yet

[jerkyboy]

Id check over the waterpump also make sure that there is no air in the system. sound like somthing is wrong if its overheating like that.

[kfx450]

just ruined a stage 6 motor same problem. run 100% engine ice. Impeler broke bike was getting hot and it was acting like the clutch wasn't working. Now new impeler but melted the o-rings. bike is eating water so we are replacing the whole thing.

[fomospede]

thanks guys, will check into a new impellar and rebuild the pump. as for bleeding the system i fill it till is solid fluid out of bleeder at top of head ,does that sound right jerkyboy ??? thanks

[jerkyboy]

That sound good to me. I also somtimes take the top hose off the waterpump just to make sure theres no air in the pump. Like said in a earlier post check impellar.

[fomospede]

took it apart impellar is perfect also pressure tested system it held for 3 hrs so it is not leaking! what kind of octane should i be running i had forgot to discuss that i know it makes a difference im running 93 but plan togo to race fuel since im running it in mine already . the squish is at .028 do i need the 112 octane or can i mix it down to 100 or so???

[rmuscle]

whats ur compression , i think u wanna make sure ur over 160psi when using race fuel like c12. if ur ganna mix it dont mix race fuel with regular pump fuel at least in my opinon . the water in the pump fuel will seperate from fuel and bike will run like crap , speaking from experiance. if ur gonna mix down c12 split it with c10 wich is basicly pump fuel without the ethanol. c10 is 96 octane . also dont know if this would matter but i think it might , what oil to fuel ratio are u running , maybe ur to lean a mixture and making bike run hot

[fomospede]

my mixture ratio is 40:1 ,compresson is 150-155psi .as for fuel all i have locally is 104 or 112 octane .i run the 112