2005 Honda TRX450R Running HOT!!! NEED HELP


I have a friend who has a 2005 450r as you can tell from the title he is having problems with it overheating. He's owned the bike since new and never had a problem, recently he went with a 520 big bore kit and a vortex adjustable ignition. Since the changes he has had problems keeping it cool. It is properly jetted and we are from Massachusetts. He has a stock radiator and fan and we were wondering if people with the larger bore combos were running different radiators. Also we were wondering if anyone has a coolant temp guage installed so we could know what temp the fan should be turning on at.

Any import would be greatly appreciated.

Thanks in advance,


try engine ice. good stuff.

Im sure a larger radiator will help ALOT!! But maybe even try to run a richer jetting, and yes 2x for engine ice! great product

Just wire the fan to direct power so it runs al the time while the key is on. Also when a radiator cap fails it will let coolant flow back to the overflow tank and the bike will get hot because the coolant system isn't under pressure. You can use stick on temp strips to see the temperature of different parts of your bike. I got one stuck to the head, top and bottom tanks on my radiator just to see when its getting a bit hot.

engine ice wont drop the temp that much maybe only a few degrees. ICE is alot more for cooling down faster and not as much as keeping high temps down. It may be worth the $20 but a bigger radiator and maybe a bit richer jetting, not so rich that it runs bad but just a tad rich, will help alot. Why a 520 BB kit on an already fast engine???

Well, thats what happens when water jackets get real thin, they dont cool! So, like everyone eles has said, big rad, engine ice, run slightly rich, and a engine fan or 2.

I have stock bore. And my 05 trx450r runs really hot. As well..

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