Extra cooling

[cbmoor]

Has anyone fitted a cooling fan to a kx5. The reason I am asking is I overheated the bike and holed a piston at my last meeting. It was a muddy meeting and I put covers to protect the rads from getting blocked and to hopefully stop the rads getting blocked. but they got blocked up instead of the rads. So that did not work out to well but I was thinking if a electric fan would help on either 1 or both rads and has anyone tried it.

 I know you do not need a fan in normal racing conditions but we are having a winter series and it will mainly be in grass or stubble field in wet conditions and the mud stick like s*** in those conditions. and the bike usually ways twice as much at the end of each race. On my crf I usually just use a a set of the wife tights covering the rad louvers and the mud just not stick to that but it did not work out on the kx. As there is a space between the radiator louvers and the radiators I was thinking of trying to fit a fan behind the rads and it would still be able to draw air through the rads and the louvers to help keep the bike cooler even when I have covers on to keep the mud out in really muddy conditions. So has any tried this and what fan did you use or got any ideas.

[kxpegger]

Goggle "anti-stick sprays" or "anti-stick coatings". There's a bunch of different types thay may help reduce the amount of mud sticking to your louvers and rads. Never tried any myself as I live in Southern Nevada... we don't have any mud here!

[Hillclimb#42]

They have an additive called "engine ice" thats supposed to reduce engine operating temps, but I would think you may have had another issue. The electric fan idea seems like a problem also in the muddy/wet conditions. It seems like if you are riding along that the engine should not over heat at all. Maybe at a long sitting idle, but maybe I have just been lucky. Kaw Rider has done some homework on this topic, however, and may be the guy to ask about reducing temps.

[cbmoor]

Thanks for the response so far, The bike is used in mx races and the roost of other bikes is causing the problem thats why I put womens tights over the louvers to stop mud from sticking but sometimes its wet mud and in clumps so it blocks the covers as well. and then the air not getting through to the rads.

I already use engine ice and have bigger capacity radiators fitted and this did not help at the last meeting. the bike had less than 10hrs on a full rebuild and was running great. Done a sand meeting and a 3hr beach race and lots of practise with out a problem. But heat from racing short tracks in muddy conditions where the bike is not getting air through the radiators is the problem. This is why I was thinking about fitting a fan or 2 fans behind the rads to help pull air through the rads. and was wondering if anyone had done this. High revs, short straights, muddy conditions = boil over and if not seen. Nice hole in the exhaust side of a weisco piston and nasty scores in the barrell

[kaw rider]

cb
there some ways you can do this. ducting to the face of radiator that the inlet is in different angle, so the angle of the duct would gather all the mud then the air would still go thru radiator. to do fans with big radiator guards. Electric fans stall out at about 160mph.

[BDI]

I hate mud like a cat hates water.I don't think I would race a race that had that much mud involved.

[cbmoor]

I hear what your saying BDI but the 500 goes through the mud no problem it was leaving the 450s for dead even more so the worse the gutter got. I just need to keep it cool though it was a blast and then it did go blast ha ha

[martinfan30]

Maybe a cooling fan from a desktop PC?

[BDI]

I don't think a fan is going to help If the rad is packed full of mud. What you need to do is figure out how to keep the mud from plugging the rad.

[jonny500]

i think bdi is right. no matter how much you try to pull though the rads it will make no difference if they are blocked. also if you run the fan from your magneto it will put more load on the engine (only small amount) . in theory this will make the engine produce more heat. just a thought lol.
have you heard of riders using filter skins on there air filters. this is where they have 2 or 3 wife tight covers over the air filter attached to string hanging out of the side of the air box and during long sand races they pull a skin off now and again taking away any sand with it. may be you could devise somthing like a goggle tear off system for your rads
have you checked your water pump impella is not lose on the shaft causing poor circulation

[Friar-Tuck]

   KTM Hardparts Cooling Fan:

http://www.dirtrider.com/drtested/141_1004_ktm_hardparts_cooling_fan/index.html

Tuck\o/

[kaw rider]

cb
you need to find a 30psi cap to keep the coolant in the system. and put a temp gauge on the coolant system. these motor will handle 250*, but if you are loosing coolant it wont help.

[cbmoor]

Again guys thanks for the imput. My rads were not blocked due the tights that were covering the louvers but if you notice there is a space between the louvers and the rads and since the tights were over the front of the louvers I was hoping to pull air in from the top and the bottom. when the tights got blocked. So that was my thinking with the fan as it would still pull air through the rads as they are not blocked it just the louvers are blocked. I know I am not writng this very well but if you imagine looking at the front of the bike, the way I have it is you see womens tights first then the louvers then the rads Hope that makes it easier to understand.

Its like what Jonny500 says a tear off system on the louvers but you do not pull the tights off and I am not sure if I would put more than one on at a time as that would also reduce airflow to the rads.

Kaw rider I like what your say I have been looking at these 30 psi caps on ebay in the states cant see them here in the U.K just not sure if that would be safe that 2.0 yes/no? I run a 1.6 in my crf and the kx had bigger rads but the cap was a 1.1 and I was also thinking about the semco hoses as they advertise it reduces heat by 5 degrees

And Tuck I really like what you posted thats what I was hoping for

Jonny500 if I got them fans I was thinking of running it like a loss sytem instead of trying to run them of the mag just fit a battery some where as a race is only 15 min and we do a max of 4 races surly a battery could handle that then just recharge it

Again guys thanks for any imput it all helps or get me thinking

[jonny500]

cbmoor, im in the uk too. where are u, im in leicestershire. if your thinking of a battery run system you could try looking radio control stuff with lithium batterys. i few of my freinds are into rc helicopter and those batterys are impressive.
p.s you dont have a good k5 flywheel do ya

[cbmoor]

Jonny500 I am in the orkney isles north of Scotland there is a good mx scene up here and sorry I have no flywheel just a blown motor and waiting on parts again for the rebiuld, the joys