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KTM cool down

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Hey All, ThumperTalk newbie here. I need some help with cooling dowm my 07 KTM 450xc-w on the trails, that doesn't involve waiting six months for a backordred KTM fan kit.I heard Gas Gas fan kits cross over, but I can't seem to find anyone who knows enough about both of them to help out. I've already swapped out my factory fluid with Engine Ice, which helped a little. But I still over heat on tight trails, and it's not even summer yet up here in the NorthWest. Does anyone know of any other fan kits that would work? I'm also not opposed to getting a new aftermarket radiator set up, as long as I can get it with a fan. Thanx

Bill

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I have an 06 450xc and it too can run rather hot when riding slow on tight trails with the kids. Usually what I'll do is ride my normal pace and stop more often and wait for them to catch up with the bike off. I guess I'll have to see what happens later on when it gets hotter out.

I think overall, the RFS like many bikes run hot at low speeds, especially if one slips the clutch a lot. About the only alternative is to either speed up, get a fan kit, or build your own kit using a cheap computer fan.

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Really with the right jetting the right amount of coolant, and not idling the bike you shouldn't overheat, fan or no fan. Have you re-jetted from the excessively lean stock set-up?

Supposedly the restrictive exhaust makes the '07 EXC's run a bit hotter; I'm not a loud exhaust fan, but steps 1, 2 & 3 for me would be fix the jetting, set the coolant level correctly (barely covering the fins when level), and remove the highly restrictive reduced diameter internal pipe.

I've never had a need for a fan or engine ice even with a highly restrictive rad guard.

Good luck

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JD kit and an RLRProduct.com coolant recover tank. i have a computer fan too but the crt is all you need.

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Do you know if I need a new jet kit or does the stock jet allow for adjustments? Also I thought the XC-Ws had the less restrictive exaust than the EXCs. Although they may be the same because KTM doesn't list the specs on thier site for the 450XC-W, they only list the specs on the EXC. I put on a TwinAir high flow airfilter that removes the stock backfire screen. But that is the only mod done to the engine portion of the bike.

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You must maintain approx. 8mph to effectivly cool a watercooled bike. Do not idle for over a minute standing still.

Be sure you are jetted correctly to begin with.

Use a High Quality Synthetic motorcycle oil. This will protect your motor and seems to run cooler also.

Use Too Two Cool additive in your oil. This also will lower operating temps.

Dwight

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My 06 525 Exc got hot and burped fluid once. it was a hot day and a slow tight trail. I have since jetted the bike, added engine ice, a coolant recovery tank and use 2 Cool in my motor oil. It has never got hot since. I was told the jetting makes the biggest difference. The bottle of 2 Cool states that it will drop your temp by up to 50 degrees.

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Cool sounds like rejetting and some oil additive might be my cure, I will give it a run and post back the results. Thanx All.

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Also I thought the XC-Ws had the less restrictive exaust than the EXCs. QUOTE]

Right you are.

Diddo on the jetting. JD kit helped me.

The more you ride the faster and more confortable you'll get and the cooler the bike will run. Find a track, and the time it has a low volume of riders and spend some time on the bike not some money:thumbsup:

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I have engine ice and the JD jetting. My 525 XC is still a tea kettle in the tight stuff. I am running 13:50 on it now. Slipping the clutch in the tight stuff really builds heat. And if you don't have enough gearing, you have to slip the clutch. I need a fan and I will also try 13:52, though I don't want to kill top end speed.

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I am still trying to figure out how to cool my 07 525, but this weekend I pulled off the highly restrictive plastic rad. guards and did not have any trouble with overheating on some tight single-track. After looking at the stock rad. guards... it is no wonder that the bike overheats with the stock guards in place. I will look for a good flowing aftermarket rad. guard setup.

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I have engine ice and the JD jetting. My 525 XC is still a tea kettle in the tight stuff. I am running 13:50 on it now. Slipping the clutch in the tight stuff really builds heat. And if you don't have enough gearing, you have to slip the clutch. I need a fan and I will also try 13:52, though I don't want to kill top end speed.

On the 525XC you should be running 14 / 52 gearing. 1st will be plenty low and you can run low enough RPM as not to overheat the engine as bad. You still need to go approx. 8 mph to cool a watercooled engine regardless of your gearing.

Dwight

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I'm sold on the idea that the top bit of coolant will overflow when it warms up. I've just run lower coolant level (about to the top of the cooling fins), never lost any more fluid after that. Coolant recovery container would accomplish same thing, better actually. This on an '07 450 XC-W.

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Running the right coolant level solves a lot of peoples problems as they think their bike is overheating when in fact its just the wrong coolant level. I do a bit of slow speed trails on my 450exc, jetted right and geared 14:49 and have no probs.

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I am also waiting for the fan which I ordered before I got the bike.

Luckly I had them jet it according to what the woods racers are using in my niehborhood.

It has nor boiled over yet and I am wallowing in mud and wacking thru half clear logging roads at slow sped..

I still would like the fan and it would be nice to break it in at lower temps as possible.

But, No real boiling problems yet. 400 plus miles, i love my 450 xc-w.

Good luck,

OT:ride:

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Didn't have overheating on my old 520MXC or the new 450EXC. But always ran Engine Ice or 2 2 Kool. Also had the stock plastic radiator guards. I think they actually help chanel the air in and give some protection for roost/debris. If you look into other radiator guards, I suggest you use the tubular KTM Hardparts guards. They don't block any airflow and still help protect the radiators from side impacts and lay downs.

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Mine has never overheated since making a few adjustments. No fan, No fancy liquids. All stock

jetting for altitude and temp. very important.

do not over fill radiator, if it is FULL, it will burp every time

14-52 gearing for the tight stuff, will still hit 85+

and most important! Keep your hand OFF the clutch lever, big 4 strokes create lots of heat in the clutch if slipped much, do not slip the clutch, let the motor do the job, it will lug down and chug over anything

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Another tip for '07 exc owners is to move or remove the horn. An easy way to move it is to unbolt the black tab at the radiator mount. Unplug the wires and pull them to the back of the radiator. Unbolt the tab from the back of the horn and put a 90 degree bend in it near the orignial mounting hole. Bolt the horn back on to the tab. Remove the headlight. Remove the right fender brace bolt. Bolt the horn on with that same bolt and angle it out to the right. Reroute the wires along the frame and clip them into the existing frame mounted plastic clip. Plug in the horn and replace the headlight. Remove the remaining silver clip from the radiator, where the original black horn tab used to bolt on. p.s. the 90 degree bend will be to the front, so you may need to insert the fender bolt into it prior to bolting the horn back onto the tab.

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