LSR crf450r overheating

[koh0001]

I have a 501 bigbore, ported head, 41mm bored carb, +1 ferrera intake, and exhaut valves, 208 web cam, PWR rad but It's getting too hot. Would a elec fan help? Is this a common prob with bigbores?
Raced tt last night 8 lap heats, 12 lap main. Inline temp gauge was pegged out when I came off the track.

[chopp124]

was it boiling over on overflow?

[koh0001]

Filling my overflow bottle up...gauge was pegged at 250

[maxamillion]

what coolant are u using? id suggest running a high pressure rad cap if u arent already to keep the coolant from boiling as easy. an electric fan will def help some.

[chopp124]

one think im toying with is instead of just running the hose from radiator strait to the motor i run a loop under the tank so it takes alot more coolant than it should im hoping that makes it even cooler. i also put a couple inline super coolers in.

[koh0001]

Just bought a trx fan. I already have a high output Stator I'll see how that works. Do those inline collers work? I have a couple off my 250r I don't use anymore. Would engine ice, and (wetter) not sure if thats how they spell it, work?

I was looking at a oil cooler they make for the crf but they want almost $300.. I'm going to see how the fan works first.

[maxamillion]

water/glycol based (reg green stuff) antifreeze will give u the best heat transfer to keep that engine cool. add water wetter, 30 psi cap, and the fan and ull be good to go.

propylene based antifreeze (engine ice) will give u better boil over protection but not as good of heat transfer. so ur engine will be running at a higher temp before it actually boils over. which is not necessarily a good thing.

[R3Concepts]

Fuel, compression, jetting?

These are where the heat comes from. Filling the overflow would also point to a headgasket.

[koh0001]

Fuel - VP C12 ,

just had new copper beryllium valve seats, and +1 ferrea intake/exhaust valves installed. Not sure what my compression is. I'm sure my head gasket is good. This was the first race since I got my quad back. Was running hot before I took it back for the head work. Just had the bigbore installed about 12 hrs ago. Ran hot since I had the work done.

Jetting - 42 pilot, 180 main, 2.25 turns out on the fuel screw.

[fmfhonda250r]

Sounds lean on the jetting. Take it to a dyno and have the afr checked

[R3Concepts]

I would probably recommend a 45-48, NCVQ or NGPR in the middle, and fatten it up until it starts to blubber bad, then lean it out 10 numbers. 10 numbers in Keihin hex is 1 point of AFR.

Shouldn't run hot on C12 even with the 40+* of timing that the CRF igntion has unless it's 14.5-15:1.

[koh0001]

I'm runninga NCVQ 4th from the top..ill start playing with the jets and let ya know what happens.

[chopp124]

idk if the coolers actually do much but there not making bit run hotter i know that and for $20 bucks its cheap enough

[koh0001]

Trx fan won't fit...too big to fit between the frame and the rad:confused: ill work on the jetting in the morning.

[koh0001]

OK, The trx450r fan I bought won't fit between my frame and rad. so I changed my pilot jet from a 42 to a 48, 1.5 turns out on the fuel screw. And took my number plate off the front bumper. Did 3 motos today and it never got over 200. I think I may need to go to a 45 pilot because I had to kick it about 8 times to get it going the last time I shut it off and tried to start it right back up.