what do you guys do to keep your 300 running cool?

[dirt-rookie]

hey guys, im fairly new here and need some help from you ktm guys. i bought an 07 300xcw this year and i love it. up until recently she has given me no problems and i love it. two weeks ago i went riding some tight single track with a buddy of mine and she did quit well all day. on the way back to the truck through some really tight low speed trail and a small hill climb when i got to the top she threw up on me out of the rad cap. it was only about 60 degrees outside and it didnt seem to be running hot. i checked the coolant level before the ride and it was full as usual and i have not had to add coolant to it as long as i have owned it and i have ridden on some 90+ degree days with no issue, though it was not single track low speed riding. do you guys think it is a cap issue or something deeper?? i havent noticed any leaks anywhere though i cannot rule that out. upon doing some research i found that the 300 has a thermostat and i am pretty sure that most other two strokers do not have one.....do we really need a thermostat? have you guys removed them with any success? what steps can i do to help keep her cool? any and all help is greatly appreciated, allthough my riding season is pretty much over for this season, i would like to get her straightened out just in case we get a couple warm days until spring.

[05victorylly]

one thing you can try is to make sure the coolant level isn't any higher than the top of the rad fins. If its all the way full it will puke when its hot.

[Just John]

If you are using the oem pilot and needle that may be a big part of the problem.

The pilot is lean and the needle is rich. In the warmer weather you were on faster trails and on the rich needle so everything was fine.

With cooler temps and riding tight s/t you are on the lean pilot and the bike is heating up. There are better needle/pilot choices...the Suzuki NECJ/NEDJ needles and 38/40 pilot will work much better.

[B Lamb]

Slow speed technical riding will make bikes run hot. True, it could be a jetting issue, but I think it has more to do with the slow speed. My advice would be to get a cooling fan from KTM. You could put a computer fan on, but the one from KTM is much more durable.

[anderini]

I would say it's probably not the cap. My 2004 250 had a bad cap and it would spit out the overflow a little all the time regardless of riding speed (once the engine warmed up). I thought I had a hose leak at first because it was more of a slow/small amount and fairly constant.

[1st4stroke41]

I just ride fast.

[cascade_crawler]

tight single track will cause any bike to run warm. With the cooler temps I suggest a richer pilot, your probably running a bit on the lean side causing it to boil. I had the exact same bike, with the exact same problem last winter. Fatten her up?

[Dave mac]

jetting

rad cap ktm sucks, the spring goes to crap in no time

Fan if you must

bigger radiator is a sure fix

[dirt-rookie]

thanks guys, i will open up the carb and see what i can find i have no idea what she is set at. that makes much more sense to me considering i had no issues in the hotter temps even at slow speeds.

[mattz]

The cap from the newer bikes is a 1.8 I think. It sured helped mine stop boiling over. A must for $15.

[canucklehead2004]

so what about completely eliminating the thermostat? is that bad? Is it necessary to have?

where do you get A 1.8 rad cap?

[scientoothical]

Of course make sure your jetted right and no bad gaskets, but if your confident with that get Evans Waterless coolant, (Zip-Ty Racing has it rebranded). You will never overheat again. Period.

It will always stay in contact with the head metal (prevents detonation)

Never build any real pressure, so you dont need a higher pressure cap and always have that much pressure in the system. (You could almost open it at running temp)

Less corrosive

Lasts forever

etc

[dhdrider]

so what about completely eliminating the thermostat? is that bad? Is it necessary to have?

where do you get A 1.8 rad cap?

T-stat is helpful if you run in VERY cold temps. The bike gets to normal operating temps quicker w/ the t-stat. It's not a must-have though. XCs and SXs do not have T-stats.

You can get a 1.8 bar cap just by ordering an OEM cap for a 2010 bike (300 XC). I am pretty sure it was in 2010 when they bumped form 1.4 bar to 1.8 bar.

part number is 77335016000.

It's $10 here: http://www.powerspor...%7e26%7c%7e0027

Edited August 30, 2012 by dhdrider

[Trailryder42]

so what about completely eliminating the thermostat? is that bad? Is it necessary to have?

where do you get A 1.8 rad cap?

No, you can not eliminate the cap. Your system would boil over quicker without it. The pressure that the cap provides increases the temp at which the water/coolant will reach boiling. Best things to do are to make sure your cap is good or replace it with a higher pressure cap like the 1.8, run an aftermarket additive, install a fan or a combo of all.

[canucklehead2004]

No, you can not eliminate the cap. Your system would boil over quicker without it. The pressure that the cap provides increases the temp at which the water/coolant will reach boiling. Best things to do are to make sure your cap is good or replace it with a higher pressure cap like the 1.8, run an aftermarket additive, install a fan or a combo of all.

did you mean I can't eliminate the t-stat? It seems like a lot people have.

[zilla]

Yes you can eliminate the T-stat.. I ditched mine on my 06 300 and installed the parts from an SX.. I also run Engine Ice.. My 12 300 hasn't boiled yet, but my bud's 07 will while on the same trails as I am.. My 06 would steam once in a while as well.. You used to be able to find 4 stroke rads on fleabay for cheap, and refurb em, then replace the 2t rads.. I haven't seen any for quit a while.. If ya have the coin there are a few places that sell larger rads.. Like Slavens.. Slavens also has a metal water pump impeller that is supposed to flow better than stock and not distort..

Edited August 31, 2012 by zilla

[gprodick]

Of course make sure your jetted right and no bad gaskets, but if your confident with that get Evans Waterless coolant, (Zip-Ty Racing has it rebranded). You will never overheat again. Period.

It will always stay in contact with the head metal (prevents detonation)

Never build any real pressure, so you dont need a higher pressure cap and always have that much pressure in the system. (You could almost open it at running temp)

Less corrosive

Lasts forever

etc

+1 on that!!!

To all 300 owners, 300's are notorious pukers. How many times have you been sitting on a slow trail, your 300 is puking your expensive Engine Ice all over the place, and you're thinking "Jeez, the bike doesn't even seem like it's that hot."? Been there, done that, got really tired of it. When you get tired of it, start thinking Evans Coolant.

I love Evans Coolant! My 300 used to puke a bit, even though I knew it was jetted just fine. It got to be very annoying and expensive. The engine showed no other signs of serious over-heating, but I would lose coolant anyway. Since I started using Evans (3 years and 8000+ miles ago), I have never given overheating a second thought. The bike runs perfectly. It doesn't puke coolant. The Evans is not water based, is non-corrosive and lasts forever. I have saved many $$$ in coolant costs. Evans may seem a little expensive, but trust me, you will be $$$ ahead in the long run, because it doesn't end up on the ground.

Try Evans Coolant, IF you are confident the bike is properly jetted, the bike shows no other signs of overheating, and there aren't other issues causing your coolant to boil over.

I know there are going to be those that claim Evans is just a bandaid, but I don't necessarily agree with that. That has not been my experience, at all.

Edited August 31, 2012 by gprodick

[randysoo]

I just went on the Evans website. They offer 4 kinds of coolant. Which do you guys use?

[canucklehead2004]

i thought they only offer one "powersport" style coolant. one is for diesel, one for auto, and maybe marine or something else. Anyways, I use the powersport one.

I took my plastic thermostat housing off thinking to replace the 2 o-rings inside that might be causing seepage.there was no thermostat inside at all!! I'll put a piece of straight pipe in and see how it goes.

[scientoothical]

I just went on the Evans website. They offer 4 kinds of coolant. Which do you guys use?

Or here http://www.ziptyracing.com/xs-coolant-1/

Same price and your supporting a moto company too. No need to buy the purge fluid, just take some hoses off and tilt the bike around using compressed air to get other coolant out. You wont be sorry ?