All 2st Which Coolant for my WR 300 that I just blew up

Re-building the top end of my 09 wr300 due to overheat issue. Not sure if i was running too lean or if it got too hot but either way it is a mess. Wondering which coolant you would recommend I use. Thanks

I use the Pro Honda HP coolant that comes mixed at 50/50. Open bottle, fill radiators, burb it, cap it, then go. I've never had any issues with it. I also use it in my '01 Honda CR 500 with good results. Sorry you burned up your 300. I just replaced my top end w/a vertex "B" size piston and kit (original piston was an "A" size). I also replaced the wrist pin bearing with an oem bearing. So far so good. Good luck!

http://www.rockymountainatvmc.com/p/43/53/211/918/-/11713/Pro-Honda-HP-Coolant

Engine Ice or that stuff Zip Ty sells.

sorry dumb question but how do you burp it? i have never done that before

If the coolant circuit is empty, or you've lost a significant volume of coolant, you need to tip the bike to the left and right at least 45 degrees a handful of times while you're adding coolant to encourage air pockets upward to the open radiator. Obviously the fuller it gets the less you can tip it over w/out spilling. I do this several times as I add coolant and can often hear gurgling noises as little air bubbles are making their way up. Don't rush this process. Add a few ounces at a time then burb it. If you fill it quickly enough to see the coolant in the radiator you'll notice it will disappear slowly as the air bubbles come up and the coolant goes down, but again, do fill it quickly enough for this to happen. I even apply the front brake and push on the bars to rock the bike forward and backward to burb it as it gets full.

works for me. thanks. I guess all babies need burped. this one is no exception. at least she doesnt cry

She doesn't cry, but she likes to scream. Gotta love the screamers!

engine ice

just fill the rads then run the bike for a couple of minutes with the rad cap off(dont rev it or coolant will go everywhere) to get any air bubbles out. those with thermostat will have to wait for it to open & you see the coolant being pumped through the system via looking through the rad cap hole. manual recommends this for coolant exchange. let it cool then top it up-good to go!

Try Evans waterless coolant ive been using for a few years now and find it really good. Im just giving you an other option to try.

another +1 for Engine Ice

I run distilled + water wetter and on the 250 it only boils over in extreme conditions.

Personally i'd never run evans because it's boiling point is too high. If my engine is that hot I want to know about it!

I just run Prestone/Peak pre-diluted

I've run engine ice before, but I don't boil over with the cheap stuff, so the only difference for me is the cost. That and if I'm in a position where I need coolant and am somewhere remote, I can pick up regular auto coolant at most gas stations, not so much for engine ice.

So I am having problems with 09 wr300 overheating. I have replaced the radiators and am running water wetter and a stronger cap. Yesterday on first ride with the new radiators my rad fluid temp got to 219 in a rocky section that was not tough but I was going slow because I was with some younger riders.

However, when I was able to open it up and get in the flats my fluid temp dropped below 100.

I have replaced my head gasket as well thinking I had a leak there.

Its really frustrating.

Starting to wonder if I have a block in my exhaust...

What is your new cap rated at? Here is a chart with the approximate boiling point of water at common cap pressures.

bar boiling point
------------------
1.2 ~ 220f
1.4 ~ 230f
1.6 ~ 235f
1.8 ~ 242f

How is your jetting? You might want to try going richer on your pilot if your going to be creeping a lot.

My 360 overheated a lot until I put on a 1.8 cap. It's a band aid in that it'll still overheat if you go slow long enough, but it usually buys me enough time.

I guess I'll check the ring and see if its right then.
And then do a leak down test?

Overheating is super dependent on where you ride and how you ride. I've only overheated my WR once, on a really long, really slow (like 1st gear pinned, spinning the tire, barely moving the bike) climb in about 85 degree weather. Then I went and rode with my brother (a beginner rider) and we/he overheated his TE 400 more times in half a day than I've ever seen in my life. We were riding in a bunch of semi-technical rock gardens, and he kept boiling over due to getting stuck, being stationary, and using lots of gas and clutch to get out.

Anyway, my point is that a bike that never overheats for one guy might overheat all the time for someone else.

I use "regular" auto parts store coolant in my WR and TE, diluted approximately 50/50. I ride a lot of 1st gear stuff and I don't generally overheat, so it works for me.

My wr300 has never overheated but my 449 boils alot in single track. I switched to maxima coolanol, seems to help. I would tell you tho to make sure you check jetting as others have mentioned, also give you impeller a check to make sure there is no issues, and also were you low on coolant when you drained it? The wr seems very resistant to boiling so I would make sure I checked everything! Goodluck