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Bigger radiator?

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I have just bought an 05 CRF250r.. im just getting used to the bike so im not riding it hard, just a small course i have made up. i find that it gets quite hot when i drive around, thought im just riding around for the most part in 1st and 2nd. it has spat out coolant, but that was only when i first got it and it was idling with the choke on for a few mins. i have since changed the coolant and dont let it idle for as long. problem solved it seems.

im left wondering when i take it out on the big track will it heat up when im riding hard, seeing as it gets hot on the small track when im going easy.

i.e. will the increase in speed compensate for the increase in high RPM?

i was thinking of replacing the radiators anyway. i don't think they are blocked internally or externally, though the grill is bent flat in places.

so my second question is

would gently straightening all the grills of the radiator help?

as for a new one. im inclined to get the far cheaper 40mm "big" Chinese made radiators, than the precision made expensive ones. both of witch claim 30% extra cooling.

bit of a ramble

thanks

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Don't know much about the bigger radiators, but yeah, once you get out on a track where you're able to go faster, the engine will cool a little bit better (more air flow to radiators). I had a CRF250R and for the time I had it, I did a lot of trail riding with it and I noticed the same thing, my engine would get rather warm cause at max I'd get into 3rd gear on a straight away and that would be for a few seconds and wouldn't come very often, but most of the time I was in 1st or 2nd so my radiators wasn't getting much airflow and a 4t race bike is harder to cool than a 2t race bike. If you'll notice, a 4t comes factory with a little bigger radiators than a 2t does, or at least it seems that way to me. Anyways, I had thought about doing the same thing, but I ended up trading for a 2t. What I've heard you can do if you trail ride a lot is use Engine Ice and I believe they make radiator fans as well, but yeah, if you're out on a track, it should cool better than just putting around.

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More airflow over the radiators improve cooling. Same with a bigger waterpump, the faster you can get the coolant flowing the better the cooling will be.

Of course, a bigger surface area on the radiator will also aid cooling.

Check the impeller before you buy anything else. I had some impellers failing when the drive pin decides to make it's own groove inside the impeller. A chep fix since the impeller usually doesnt cost much and it will get the coolant flowing again.

If the riding is so slow that it still boils, you need to increase airflow over the radiator. A fan will sort that out.

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