Bike getting Hot! What can i do??

[Grande Huevos]

Hey guys i have an Esr 330, 38mm a/s trx 5 pipe, new Esr temp guage between rad and impellar and I cant get this thing 2 run cool for the life of me!I have alumm shrouds new mechanical seal, the impellar and everything is either new or in great condition. Radiator cap is fine and iv completely flushed my system and refilled w Engine Ice and still no change in temps. My carb is jetted way fat and it still gets hot. when i putt around on an open dirt road it will consistantly stay at 175-200 but as soon as i start rippin or get out of the open areas my temps shoots to 220 within 5 min and would prob climb but i shut her down. This is driving me crazy because i cant even have run riding my baby!!! My next step is 2 buy an oversized radiator but ive heard from multiple people that they dont really make a diff???? Im not for sure i agree but i dont want 2 spend $400 if it will not help me. Has anybody ran big bores w stock radiator??? What ballpark temp should it be?? I kno the stock sized cylinders should b 150-180 and would assume bigger motors put off higher temps?? If anybody has any advice or tricks please let me kno because fall is coming fast and i have to be able 2 ride!!!!!!

[slamdak8782]

You can get a bigger radiator. Use higher octane fuel. Run less compression. Probably higher octane fuel and make sure your radiator is burped correctly.

[Honda 250r 001]

Ive had the same trouble as you for 7 years. The problem with mine was my radiator wasnt getting enough air flow. I had a huge DG national 2 front bumper on which blocked ALL airflow and mine would get hot and run 250+ constantly. Try removing your front bumper and run either the stock one, or no bumper, and (if you have one) remove the aftermarket mud screen and install the stock one.

This is all i had to do to mine and how it runs 150-180 even on the hottest days racing supercross.

[Grande Huevos]

Originally posted by Honda 250r 001
Ive had the same trouble as you for 7 years. The problem with mine was my radiator wasnt getting enough air flow. I had a huge DG national 2 front bumper on which blocked ALL airflow and mine would get hot and run 250+ constantly. Try removing your front bumper and run either the stock one, or no bumper, and (if you have one) remove the aftermarket mud screen and install the stock one.

This is all i had to do to mine and how it runs 150-180 even on the hottest days racing supercross.

yeah I took the mud screen out completly and drilled out all the holes in front bumper. What size motor were u running? Do you kno if the oversized rads make much diff at all?

[310DUNECLIMBER]

my new esr 310 when i had it ran around 200 to 220 when i was sand dragging,but topend was fine ,ran engine ice aswill

[Scottt89]

Was having an issue with my KX450f Dirtbike overheating when I was lugging through tight woods or stuck idling. Engine Ice wasn't helping. I switched to Evans waterless coolant and did a Harescramble race yesterday. Didn't lose an ounce of fluid. It's rated for a 400deg boiling point. All it takes is draining your current AF and running a prep fluid for like 2min then filling with the Evans.

[Motofool250r]

are you loosing any coolant or getting any oil/gas in the coolant?

have you had the radiator professionally flush like dipped in hot tank to get the grudge out of the radiator blocking the flow possibly causing this?

no mud guard no front bumper blocking,

good water impellar, no leaking orings/gaskets on head or base, your not getting coolant flow it sounds like plugged radiator or something is not letting coolant push through

[Grande Huevos]

Originally posted by Motofool250r
are you loosing any coolant or getting any oil/gas in the coolant?

have you had the radiator professionally flush like dipped in hot tank to get the grudge out of the radiator blocking the flow possibly causing this?

no mud guard no front bumper blocking,

good water impellar, no leaking orings/gaskets on head or base, your not getting coolant flow it sounds like plugged radiator or something is not letting coolant push through

well i took it out yesterday evning to tinker with her. Im not loosing any coolant or anything like that. I ran it without my front plastics and it made all the diff in the world. I ended up dropping my main from a 185 to a 178 and actually got a chance to feel my bike perform and was barely breaking 200 degrees after 15-20 min. I have fullbores on with a scooped hood and need to cut the nose out of them and route the scooped air directly to my rad. Hopfully it will fix my problem

[Motofool250r]

no radiator shrouds?

[Grande Huevos]

Originally posted by Motofool250r
no radiator shrouds?

yeah i ahave aluminum ones but my scooped hood is directly mounted on top of my fullbores, i never cut the center out so the scoop isnt doing anything as of right now. Im going to fab it up this weekend though