Hi

I have a low hour 06 WR450 that I ride in a lot of steep tight slow 1st gear riding and I'm having overheating problems.

I have fitted a 4" spal cooling fan to the right radiator controlled by a switch on the handlebars and it stops the overheating but flattens the battery (6mths old) within an hours riding. So I can have a cool running kick start only bike or an overheating electric start bike....

Apart from an externally adjustable mixture screw the jetting is stock and runs really crisply off the low end.

Would richening up things a bit cool the motor and if so what jet controls the mixture at low throttle openings (FCR)?

I'm also running a stock exhaust complete with the restictive end bung - would lowering the exhaust back pressure (with appropriate jetting changes) cool the bike down at all?

Does changing the ratio of antifreeze to water change cooling efficiency or does it just change the boiling temperature?

Anything else I can try?

Thanks


Mark

Mark, Yes all of those things you mentioned will help your bike run cooler. Stock, the WR is notoriously lean and this will cause it to run hot. So will the restrictive exhaust. As for the water/antifreeze ratio, I'm not sure if changing that will help or not. But I do know that there are different types of coolants that you can add instead that are supposed to help, such as Engine Ice, WaterWetter, etc..
Maniac

MANIAC998, on 13 February 2012 - 02:51 AM, said:

Thanks for the response

I just went out to the shed and put a jd jetting kit in the bike and changed the coolant to 25%/75% and ordered a new agm battery

I'll see if these changes make a diiference and uncork the exhaust as a next step.

How slow is your riding. I have an 05. What really gets me boiling is clutch use. You simply have to stay off of it or you are going to boil the coolant every time.

Find a gear where you can stay moving without the clutch. For me, that meant gearing up (not down). I LOVE the slow technical stuff. I use to have 15/50 gearing and I'd be clutching a lot in 1st gear to tame the power or clutching a lot in 2nd gear to give me more power.

then I went down two teeth in the back to a 48. It made 1st gear more usable and not so twitchy, yet it rev's out further to allow me to keep using it instead of shifting to second. The slightest bit of airflow, even at slow speeds will cool things off considerably.


Of course I still use the clutch, a lot in fact in the slow stuff. But, i don't use it nearly as much now that I can carry more momentum in first gear without riding the clutch so hard.

Your experience may vary.

Heck! I forgot one of the most effective, and cheapest ways to lessen boil over! Get one of those higher pressure radiator caps, like CV4. They'll take alot more heat before they open up and boil over. And like Maurice said, stay off the clutch!!!
Maniac

So If it boils over its not damaging the engine yet?

mauricedorris, on 13 February 2012 - 11:43 PM, said:

I ride super tight hilly trails and have a rekluse clutch set up with soft engagement and higher engagement speed so the clutch gets a real work out - especially since I put on a trials tire which eliminates a lot of wheel spin

Without the rekluse my clutch hand gets too sore to use after a days contsant clutch work. The prime symtop of imenent overheating is the clutch starting to grab. I use 14/50 and seldom get out of first for long.

MANIAC998, on 14 February 2012 - 04:41 PM, said:

My biigest problem is not the boiling as such its the clutch becoming really grabby from all the heat

Stealth13, on 14 February 2012 - 06:41 PM, said:

I hope not - If the coolant in my overflow tank starts to boil I get of the bike straight away and have a sit down - same with the clutch - if it start grabbing I stop riding.

A friend of mine uses Evans waterless coolant in his Husaberg 570. 570's run much hotter than WR's. He said the Evans stopped his from boiling.

http://www.evanscool...sports-coolant/

If you stop riding when your bike starts to boil over, you won't cause the bike any harm. But you are close to causing damage though. Have you tried a 51 tooth rear sprocket? That's what gearing I use for the race season here in Montana. Something as simple as this might be all you need to help keep it from getting so hot. Maniac

you could always rewire your stator to comensate for the fan draining your battery too.

Charles De Mar, on 15 February 2012 - 07:21 AM, said:

This seems like the best solution to me if unplugging the exhaust and rejetting doesn't solve the issue.

Float the ground on your stator, get a 100% DC reg/rec and an HID light and you are good to go. It will charge your battery much faster than stock, plus you will have a brighter headlight and it will only cost around $60 for everything you need.

I did this because I have grip heaters for the winter and they would drain my battery to the point where I couldn't use the e-start. Did this mod and have had zero problems since even when leaving the grips on and bike off for up to 5 min or so at trail intersections (and heaters take a LOT of power).

Charles De Mar, on 15 February 2012 - 07:21 AM, said:

woods-rider, on 15 February 2012 - 07:45 AM, said:

I agree that enabling the fan to run without running the battery flat is a sensible thing to do

I was considering this trail tech stator upgrade although it will cost about $300NZ by the time I get it landed in NZ

I don't run any lights by the way

would you mind explaining in a bit more detail how I can rewire or modify my stator for more output?

I have two 06 wr450's and my old one is fast becoming a parts bike so I can play with the stator from that one.

Thank for the feedback

cheers

Mark

Just search this forum for floating the ground and you will find some good threads and some instructions on how to do it.

Charles De Mar, on 15 February 2012 - 01:20 PM, said:

If you do this, you will not be able to run the stock light, even if you wanted to. You will need an HID light setup. Oh, won't you also need a DC voltage regulator?

mauricedorris, on 15 February 2012 - 04:49 PM, said:

yes you will need a new voltage regulator. My stock headlight runs just fine.

Thanks again for the responses

I have to confess to being a bit confused

according to my 06 wiring diagram I have one ac generating coil in the bikes alternator/magneto.

this seems to power the ac headlight and tail light directly and the dc via the recitfier/regulator

if I hook a 30-40w fan to the dc side the battery goes flat implying that either not enought power is being generated or the regulator somehow limits things

if the alternator is capable of running 30-50w of lights off of the (unregulated?) ac circuit as well as keeping the dc side running why cant I put a rectifier on the ac light feed and power the fan from that (seeing as I dont have any lights)

ricky stator does a 100w stator/regulator kit for $150US (about $230 to me which I can live with) - does anyone have any experience with ricky stator?

I'm all ready for another test this weekend (really looking forward to a ride) - new agm battery, new jetting etc etc

next step will be uncorking the muffler (welding a bigger pipe into the restictor plate) and tightening up the engagement spread of the rekluse so I'm not working the clutch plates so hard

Thanks again guys

Just an update for all who took the time to respond

Went for a fairly epic ride yesterday and the bike definitely ran cooler with the new jetting, different coolant mix and uncorked exhaust and I was also able to run the fan all the time I was riding in first (which was a lot) without flattening the battery
I didnt boil once nor did I get it hot enough to make the clutch play up. I suspect my 6 month old battery was stuffed. I put the new motobatt battery on charge this morning and the charger said it was fully charged so I hadnt been progressivly flattening it over the day.

I really notice the heat on my knee/shin with the fan running so its clearly moving some serious heat away from the radiator

thanks again everyone for all the feedback

My bike used to run hot. As soon as I uncorked the exhaust (actually changed the exhaust) and rejeted it there was no more heat problem. I would go with uncorking the thing first.

Just my thoughts since it worked on mine.