[rodH]

Sorry to start another thread, another question.

Sounds like there are some key things in keeping an MX cooler for slower trail use.

1. Use good/cooler coolant. Which one is best (I’ve been using engine ice). Is there a better one or an additive that improves it?

2. Larger radiators?

3. Larger water pump kits. I am seeing the Boysen kit all over the place for around $200. There also seems to be another kit for under $100 that uses a much larger impeller and a spacer to accommodate. Link below. Has anyone tried this kit? Opinions?

4. Change radiator cap

Any other ways to decrease temps? Thanks!!

[JimDirt]

Yea , that is pretty much it , either Engine Ice (what I use) or Evan's Waterless ,is fine , the 1.8 cap , and/or larger radiators , you can run ( this is what I did for my 02) , a 250X Overflow Tank (I got mine used on EBay for like $25 with all the hoses) ,and mount it on the rear of the bike like this





I just made my own mounts for it , just make sure it is far enough to the side to allow the rear wheel to travel ....

Also , gearing lower will help , the less you use the clutch the less heat the engine will generate , as the clutch overuse in slow conditions contributes to most of the heat , and a Rekluse will generate as much heat as just slipping the clutch with a manual lever .... so it won't help for heat , just ease of riding in tough areas .

[rodH]

Yea , that is pretty much it , either Engine Ice (what I use) or Evan's Waterless ,is fine , the 1.8 cap , and/or larger radiators , you can run ( this is what I did for my 02) , a 250X Overflow Tank (I got mine used on EBay for like $25 with all the hoses) ,and mount it on the rear of the bike like this





I just made my own mounts for it , just make sure it is far enough to the side to allow the rear wheel to travel ....

Also , gearing lower will help , the less you use the clutch the less heat the engine will generate , as the clutch overuse in slow conditions contributes to most of the heat , and a Rekluse will generate as much heat as just slipping the clutch with a manual lever .... so it won't help for heat , just ease of riding in tough areas .

Thanks for the info Jim!!!

Weird question but what is the coolant reservoir for? I imagine that it is in case it begins to over heat and the excess fluid has somewhere to go, but how does this help keep your bike cooler? Once you lose the coolant, isn’t it gone?

Also, any opinion on the Boysen or other water pump product? Thanks!!

[JimDirt]

The bottle is just like the overflow bottle in your car/truck , when the engine gets hot on your bike , the coolant blows out the overflow , but ends up on the ground , but with the overflow tank , the coolant goes into the tank , then as it cools down when moving faster , it returns the majority off the coolant back to the cooling system , , you may get some loss , but 1/10th of what it would be without one ..... So what makes it keep the bike cooler is , you are not losing the amount of coolant you would with just the overflow line , so that in itself keeps the bike cooler .... it is basically just another source to add to the other items , so together it adds up... which is the goal ....

As far as the pump goes , I have always used the stock water pumps , so I don't really have a answer ... so hopefully someone else will chime in with a suggestion , or some experience with one of them , to help guide you in the right direction .... On my 450X for example , I use a thermostatically controlled cooling fan , unfortunately , with a R you can' really do that , since you need a battery to power the fan , which is just not feasible on the R .... , but anything that helps or adds to something else you are using , will all add up and help keep it cooler ..... so basically , if you have the budget for a pump , then add it , it won't make anything any worse .. and can only add to the arsenal ....

[rodH]

Thanks Jim. I also just checked and my radiator cap is 2.0. I have read some people do 1.6 and others 1.8. You have good luck with the 1.8?

[JimDirt]

Yea ... Even the 1.6 is better than the 1.1 stock , it just allows the temps to go a bit higher before blowing off , the higher the blow-off (to a point) is better because you do not lose coolant till then ,as opposed to right after the bike gets to operating temp like the stock one ..... Like I mentioned before , it is a combo of things to get the bike to lessen the overheating from coolant loss ...... but no matter that ( on the R anyways ,because the X can have a fan) if you go slow , the only cooling you have is the air flowing thru the radiators ,so the slower you go , the less air and the more heat , so its all a compromise .... but with my bottle setup , I ran my R thru lots of miles of tight single track ...... but for a trail bike , even though my R is 40 lbs lighter , I still love the X , it will go just as fast , and go even slower than the R ( especially with the fan) , with a Flywheel Weight , the R is a fun light MX bike that you can trail ride .... but make no mistake , it is far from a trail bike ...

There is no way I would take my 20 450R on a trail ride , it would be out of coolant the first 1/4 mile ..... that is why I have the X for off road , it is hands down the best trail bike you can get from Honda (the 250X is good as well , but for a heavier guy like me , it just does not have the power I need to pull my weight around , especially on steep stuff) , but with the exception of a older air cooled XR 250 or XR 400 , the X is the way to go if your main goal is trails/desert

This is my 06 450X

[rodH]

This is some great info and help. Just by way of update, ran the bike on Sat, mostly dual track, fire roads, road (to get to dirt) and a few short single tracks. I installed a small fan on the L side with a Tusk Termostat kit set at 190 degrees. (basically, I just added a 4" fan to the Tusk kit). It was 85-90 degrees outside and we were mostly in sun and mostly moving. The bike didn't seem to cool down as much as running around my streets (granted, I live in much cooler area). On my Tusk 1.8 bar thermometer radiator cap, I was showing that I was pretty much 190-200 degrees the whole time. It never got as cool, in the 170 range as my streets and never got as hot to boil over (mid 200s), but I am willing to assume that in much slower/technical single track or a 100-105 degree day, it would get hotter. I also did the turkey baster mod, and I never lost coolant.

My question is, is 190-200 around the right running temps? I have another fan that I was planning on installing to R side as well (just didn't have time to do it before this ride. I also have a high flow water pump kit (similar to below link) that I didn't install yet (limited by time). I was also planning on getting larger radiators and better hoses (people talk about a Y hose, why is this supposed to be better?). I am just worried that if it is much hotter and/or we end up riding much more technical/slower, I wont be able to keep the bike cool enough (also note-I have a rekluse as well, which I understand might contribute to the bike running warmer).

[JimDirt]

Yea , that temp is normal and fine , remember that the higher pressure cap raises the boiling point where it will spill out the overflow , so with the 2.0 , you will probably get closer to 220 or higher before boil over begins , you do not have to worry about engine damage till you get closer to the 300 range , so like 250 -280 , is getting a bit HOT to where you want to think about getting to a more open area , or stopping for a while taking a drink break and giving the bike a heat break and letting it cool down before continuing ...

You did not mention if the fan kicked on while riding , if not , then you were not in any danger , and even if it did , I would expect it to shut off once you got to more open areas ......... my 02 with just the 1.6 cap , Engine Ice and the 250X overflow bottle , went on the same tight single track as my 450X , and neither bike got HOT , my X has the fan , and it rarely came on , only when I sat in 1 place for too long , just remember that airflow thru the radiators is what keeps everything cool , so as long as you are moving , even if walking pace , it is better than sitting in 1 place for any length of time ......

I think you should be fine , and should not have to worry about the bike overheating .... just pay attention to when the fan kicks on/off , and what you are doing when it does , that will give you a guide on how to ride efficiently without overheating the engine ......

As far as the hoses go , what the difference is , is Silicone , it is more resistant to heat cycles than just rubber , as rubber over time gets stiff then is prone to cracking/splitting/leaking , the Y is just a less restrictive junction , so the water is not restricted going thru the slightly smaller metal fittings , so it helps cooling efficiency .... so yes the Silicone hoses are better , you do not have to buy the real expensive ones , the ones I got for my 02 were from EBay and decently priced (well under $100) , but they just add to making the cooling system more efficient , so it is worth the cost ........ Same goes for the oversize radiators , the more cooling capacity you add , the longer the bike will stay cooler even in the tougher slower riding areas .......... it all adds up and works together , each thing will help , and using all the options help even more ... cooler is better ... period ....

[rodH]

Yea , that temp is normal and fine , remember that the higher pressure cap raises the boiling point where it will spill out the overflow , so with the 2.0 , you will probably get closer to 220 or higher before boil over begins , you do not have to worry about engine damage till you get closer to the 300 range , so like 250 -280 , is getting a bit HOT to where you want to think about getting to a more open area , or stopping for a while taking a drink break and giving the bike a heat break and letting it cool down before continuing ...

You did not mention if the fan kicked on while riding , if not , then you were not in any danger , and even if it did , I would expect it to shut off once you got to more open areas ......... my 02 with just the 1.6 cap , Engine Ice and the 250X overflow bottle , went on the same tight single track as my 450X , and neither bike got HOT , my X has the fan , and it rarely came on , only when I sat in 1 place for too long , just remember that airflow thru the radiators is what keeps everything cool , so as long as you are moving , even if walking pace , it is better than sitting in 1 place for any length of time ......

I think you should be fine , and should not have to worry about the bike overheating .... just pay attention to when the fan kicks on/off , and what you are doing when it does , that will give you a guide on how to ride efficiently without overheating the engine ......

As far as the hoses go , what the difference is , is Silicone , it is more resistant to heat cycles than just rubber , as rubber over time gets stiff then is prone to cracking/splitting/leaking , the Y is just a less restrictive junction , so the water is not restricted going thru the slightly smaller metal fittings , so it helps cooling efficiency .... so yes the Silicone hoses are better , you do not have to buy the real expensive ones , the ones I got for my 02 were from EBay and decently priced (well under $100) , but they just add to making the cooling system more efficient , so it is worth the cost ........ Same goes for the oversize radiators , the more cooling capacity you add , the longer the bike will stay cooler even in the tougher slower riding areas .......... it all adds up and works together , each thing will help , and using all the options help even more ... cooler is better ... period ....

Awesome, thanks!!! I also put on a 12t front (40mph in first gear is plenty and that gearing should help me when riding tighter trails). Did I mention that the 450 is still a monster, no FI, nothing super fancy, but the suspension and motor are soooo good. No problems keeping up with my bros Husky 350. The battery, lights, fan have made it a bit heavier, but I estimate that I am still 10-15 lbs lighter than even his husky or comparable KTM, and i've still got about 10 more HP. The MX tires were chunked like crazy, so thats going to need to change (and possibly 18" rear).

[JimDirt]

Cool , sounds like you are heading in the right direction ...... Just keep watch on the chain slider and swingarm ..... with a 12t it will be tighter around the swingarm , so it can actually wear thru the slider faster , and , it can actually wear a hole in the swingarm (I have had that happen) , the 18" tire will give you more sidewall , so a slightly plusher ride , and better grip around rocks/roots etc. and less chance (does not eliminate it) of a pinch flat .... For off road , I personally run Tubliss in my bikes (I use them on the MX track as well) , that way for off road you can run real low air pressure for better grip and it is about impossible to get a flat (unless you slice the sidewall) , I run around 6 psi in my 450X rear with a Kenda Equilibrium , and about 10.5 psi on the MX track on my 02 R (I did , I removed them as I am selling the bike , and will be putting the Tubliss on my 20 450R as soon as I swap out my wore out tires (I already wore the tires out in a little over 20 hours on my 2020)

[rodH]

Cool , sounds like you are heading in the right direction ...... Just keep watch on the chain slider and swingarm ..... with a 12t it will be tighter around the swingarm , so it can actually wear thru the slider faster , and , it can actually wear a hole in the swingarm (I have had that happen) , the 18" tire will give you more sidewall , so a slightly plusher ride , and better grip around rocks/roots etc. and less chance (does not eliminate it) of a pinch flat .... For off road , I personally run Tubliss in my bikes (I use them on the MX track as well) , that way for off road you can run real low air pressure for better grip and it is about impossible to get a flat (unless you slice the sidewall) , I run around 6 psi in my 450X rear with a Kenda Equilibrium , and about 10.5 psi on the MX track on my 02 R (I did , I removed them as I am selling the bike , and will be putting the Tubliss on my 20 450R as soon as I swap out my wore out tires (I already wore the tires out in a little over 20 hours on my 2020)

Great, i'll make an effort to monitor the swingarm, thanks for the heads up. in the research I have done, it does appear that running some kind of tubeless situation is a very good alternative to running low pressure (increase grip) and avoid pinch flats and the 18" giving even that much more runner to the tarmac. I have looked into tubliss system, and use to work at a bike shop way back and we use to run DIY tubeless systems. I have seen some youtube videos on this for dirtbikes as well. Are they fairly reliable or is there a huge issue compared to the Tubliss? This is an issue I am currently looking into as I could tell I need more rear traction and my MX are super chunked!! So going to an 18" running proper pressures and proper tire is something I am looking into. Thx

[JimDirt]

The biggest issue with a Tubliss , or a copy of such , is making sure the tire is sealed and no air leaks ......

If you use Slime on the bead of the tire , and have the rim taped around the spokes you will be pretty good (with the Tubliss) the main thing about the Tubliss is the small tube/bladder that pushes against the bead with 100+ psi and that keeps the tire sealed to the bead , so when running low pressure you wont lose the seal , I love them , and a few of my friends that moto and off road ride use them , as pinch flats are common with a tube , but not with a Tubliss , you have to tear the sidewall to get a flat ......

On a side note , the tire can still slowly leak thru permeation , as a "Tube" motorcycle tire is not the same as a tubeless like what is on your car , the rubber is different and it will bleed air thru the tire itself , so if left sitting for more than a week , it will have a noticeable difference in air pressure , I can usually go 2 weeks with a new tire , as the tire ages/wears/softens , you will see a pressure drop in that time , if it wears to the point that the knobs start tearing , you will lose pressure faster as the carcass is now exposed ...... and a old/used tire will usually leak no matter what you do , so mount a new tire if at all possible ............I have run the Tubliss for about 5 years now , the advantage they have over a tube , or even over a Moose insert , is major , the Moose will soften as you ride and especially if you ride faster open terrain , it will heat up and start breaking down quickly like if you get a month out of a Moose you are lucky .... so longevity of the Moose is about 1/32nd of what a Tubliss is or even a regular tube , I have had the same set of Tubliss for those 5 years with no issues .....

[rodH]

The biggest issue with a Tubliss , or a copy of such , is making sure the tire is sealed and no air leaks ......

If you use Slime on the bead of the tire , and have the rim taped around the spokes you will be pretty good (with the Tubliss) the main thing about the Tubliss is the small tube/bladder that pushes against the bead with 100+ psi and that keeps the tire sealed to the bead , so when running low pressure you wont lose the seal , I love them , and a few of my friends that moto and off road ride use them , as pinch flats are common with a tube , but not with a Tubliss , you have to tear the sidewall to get a flat ......

On a side note , the tire can still slowly leak thru permeation , as a "Tube" motorcycle tire is not the same as a tubeless like what is on your car , the rubber is different and it will bleed air thru the tire itself , so if left sitting for more than a week , it will have a noticeable difference in air pressure , I can usually go 2 weeks with a new tire , as the tire ages/wears/softens , you will see a pressure drop in that time , if it wears to the point that the knobs start tearing , you will lose pressure faster as the carcass is now exposed ...... and a old/used tire will usually leak no matter what you do , so mount a new tire if at all possible ............I have run the Tubliss for about 5 years now , the advantage they have over a tube , or even over a Moose insert , is major , the Moose will soften as you ride and especially if you ride faster open terrain , it will heat up and start breaking down quickly like if you get a month out of a Moose you are lucky .... so longevity of the Moose is about 1/32nd of what a Tubliss is or even a regular tube , I have had the same set of Tubliss for those 5 years with no issues .....

Just going thru this old thread (for some reason, I still don't get email notifications).

Thanks for all of the info, good stuff!!! I got my new wheels (18" rear) and I installed the front using the "grease the tube and inside of the tire" method, which really makes a lot of sense to me. Then I kept thinking about it and decided to go Tubliss on the rear (will probably eventually do front as well, but since usually u get pinch flats in the rear, I will start there). At first I got the tubliss and being in the bike industry so long, I was a little disappointed that basically all it is is a road bike tube (that can handle high pressures) and a road bike tire that is red (the "liner") and thought to myself, "I could easily put something together like this on my own". Then you realize that 18" road bike tubes and tires are extremely rare and when you do find them, the tires are over $40 and tubes are around half of that, add to that some modifications to have a rim lock, etc....and the cost of $90 for the real system doesn't make sense as a DIY proposition. Then I thought back when we were doing DIY tubeless systems on bikes in the 90s, (sealing the nipples/rims, etc... and I started to research that, and found it is fairly common in the supermoto community. I seriously thought about doing this, and then reality hit as to why it is popular there but not the enduro community. In Supermoto, if you get a flat, you walk your bike at most a 1/4 mile to your pits, in an enduro situation. NO ONE wants a flat from not creating a perfect seal and be 30 miles in the middle of no where (at least this is my conclusion on why we don't see it with enduros).

At any rate, installing soon, and its good to know that Tubliss works well at higher speeds, as we do ride street a few miles to get to some riding spots. Thanks again!!

[JimDirt]

No problem , glad I could be of some good info for you ....I actually just transferred my Tubliss setup from my 02 450R to my 2020 450R , and I could not be happier .... the track I ride has a lot of square edge holes and a bunch of G-outs , so getting a front and/or rear flat is common place ..... the Tubliss just made my life much easier , as I was afraid to hit stuff fast with the stock tubes in place on my new bike , the nice thing is , the system I have is like 5 or more years old , and still is holding up and now on its second bike ..... can't complain about the cost versus longevity with those numbers .... , I would have spent 3 times that amount on tubes in that time .... , as do some of my friends I have not been able to convince , as they look at the cost and figure a tube is cheaper , but when you replace 20 tubes in a year , which my friends do , it makes perfect sense (or cents) to use the Tubliss ..... I will never go back to tubes .....