250-500cc WR thermostat bypass

need some help kids...(i know, humbling isnt it...)
i'm looking for a RT side radiator hose or combo set for my 2012 WR300. im trying to remove that inline thermostat. i dont wana pay 120$ for a silicone set if i dont have too for one lousy fitting or a couple of small hoses and some couplers and clamps. im off to the marine store right now to see if i can find a stainless fitting that's close to what the theremostat is, this place has a ton of wonky lookin stuff. if i get lucky and find something close i can fab some stuff from there but, ya think the 2010 RT side radiator hose will work on this 2012 cuz i think the 2010 had no t-stat right? anyone bypass their t-stat? ok, off to the store ttyl thank you. baaaroop!

Why do you want to remove it?

Just out of curiosity, why remove it?

I think pvduke had mentioned a boil over in another thread.

My 2011 300 boiled over a fair amount in slow nasty stuff until I put a higher pressure radiator cap on. Much better after that. Stocker is a 1.4 ATM. I got a cheap Tusk 1.6 ATM from RockyMountainATV/MC. $15.

When the bike was new I dumped the ... whatever it was... from the cooling system. It had a lot of sediment and/or oil in it.

after a long hard section followed by a steep greasy pitch where i gota slip the clutch it'll heat up, other than that it's fine, cept for the first warm up it squeals like a piggy, kinda funny, stopped on the first climb all wtf is that? looked at the cap then touched the t-stat and could feel it buzzing. pfft. back on with the ride. i dont like having something that can fail and leave me hanging in the middle of purgatory- if it breaks up it'll kill the pump, then yer rides over and its a long walk. it's also plastic with a crimped ring holding it all together. forget that. it's already off the bike and gone before my next ride. no business being on there at all on an enduro bike.

i got it out and into a pan of water and even at full open it's really restrictive. im not sure why they have that on there, maybe for the street legal bikes? that's the only logic i can think of for it.

im thinkin a stainless 23mm elbow from the head to the left rad upper hose, then, trim back and block the 13mm hose with a custom plastic plug (not metal!) so the flow goes one way and un-inturrupted. that or 2009-2010 hoses if they'll work. my jettings spot on i just need more juices flowing. ive never had a husky 2T or any my bikes boil over when jetted right and im making any sort of progress. jeez the thrashing id give my '09 WR125 was pretty brutal and it never overheated, it shoulda blown up!

ive popped hoses, HG's and peed hard past the cap getting stuck, abusing stuff and not stopping for a cool down on other bikes but...if im making any sort of progress and not smoking the clutch it shouldnt pee a lot even with light cap weight. it wasnt a giant WOOSH steam cloud and after a 10 min set i pulled the cap and nothing went blewy out the spout. but i could tell it was getting too warm and gugrling under the cap. it needed 4-5 oz of water and i topped it off before the ride (as its normal to loose an ounce or so per ride cuz after shut off it pees past the cap.). i pulled the pipe today just to check and it's kosher no scuffs. its also impossible to tell if the coolant's actually getting into the motor or if yer just filling a radiator.

long stroke is right the factory coolant looks like guido at the factory took a whiz in there...what the hell was that stuff???? it was nasty! looked blue a first, now its yellow. good thing is there's a few really nice dirt bike specific coolants out there. so its getting a flush with distilled water then some of that for sure.

so anywho if there's some stuff you guys tried on this or if you have any good pics of 2009-10 WR's hose configruations i can get some ideas off by all means please share it. thanks!

If you're asking why bypass, you've never had a thermostat get stuck. As long as you let it warm up, it's really just something else to break.

I've seen a guy that replaced his with copper pipe. Kinda looks hillbilly, but more resistant to shrubs trying to catch it. Would hate to catch that on something solid though.

I've still got mine off, but this is on my list of things to do.

Ended up pulling mine off as well, its a piece of junk. Capped the smaller hose and put a brass elbow from Home Depot on the other 2. Yes a 10' will work but I believe you need 2 hoses not one. Going to do the same thing.

x2,did the same thing,wanted to spit on me until I took it out. I race the bike so didn't want the chance for failure either.

I still have mine in without any problems. But if it is like a auto t-stat, you can cut the guts out fairly simple.

i looked at the t-stat for 2 seconds and realized what a mistake it would be to try and modify or gut it. im sure it's fine for whatever intended use it was for, say street riding in a place these are legal for that, but man for hard stuff or back country use? fugettaboutit! gona use the home depot thingy for now that'll do fine. im trying to source a nice 90* barb fitting to make it sano found one alloy in -12 or thereabouts at O'riely auto parts for climate control, need to go check that out, and, a local marine supply store by the harbor looks promising. so far the rest ive found are plastic. Earl's used to be down the street here, no not more. so that blows. i could walk in with a scribbled drawing and walk out with some pretty hose and ends and goodies.

oh yeh and i just orded up some XF+ from our newest sponsor. and you should too! so get to it people! ......braap!

i also like to route and trim the over-flow hose to pee on the pipe. that way if i do get in trouble it'll let me know by smell long before i melt it down.

steam cleans yer boot while you ride...it steams as it cleans and you braaaap! faster ya go, the cleaner you get. now ya know why my boots stay clean and my bike looks trashed.

and you though i had mad skills.

....i think i found what i need for the elbow to connect the two hoses. a/c line coupler dealio. spritz this black and stuff it on. never know i was in there.



next to trim the 13mm ID line, then, plug it sano like. talked to zip ty and the FX is water-less so alloy stuff is no problem.

Northern Cooling Systems- supplier of radiators, bungs, parts, couplers etc. Neat stuff. ... 1", 90*. i prefer a radius bend but....this is kinda sano too.



im still diggin...stand by....

I uncrimped mine, took out the guts,and tapped and threaded a bolt into the small pipe coming out of the bottom which would be the bypass. I then crimped it back together. Just make sure the bolt is a tad big so it will go in tight. If needed i'll take it apart and tell you exactly what i used.

I was wondering if that could be done. So the plastic isn't glued as well, just crimped together with that metal band?

ok- this project just went postal. from all kinda plastic and brass widgets and stuff to...a trip to the hot-rod store for some -12AN PTF stuff. stand by for surgery people!!!

see? that's guts. i looked in there and said, hmmm...i can do this. then, i chickened out. i fear the unknown. esp plastic stuff with a crimp ring. my hat is off to you man. good job.

justpinit- dont gota tear her down man! my t-stat's on the bench.

080- ID of the lil spigot is 8mm. or a loose 5/16".

Not sure exactly. I just put a brass plug in it, thought it was a 9/16". Talking about the small hose correct?