SV650.org - SV650 & Gladius 650 Forum



SV Talk, Tuning & Tweaking Discussion and chat on all topics and technical stuff related to the SV650 and SV1000
Need Help: Try Searching before posting

Reply
 
Thread Tools
Old 20-07-18, 06:20 AM   #1
Seeker
Member
Mega Poster
 
Seeker's Avatar
 
Join Date: Jun 2016
Location: NE Lincs
Posts: 1,066
Default Cooling fan

I was reading a thread on the US site where a new rider was practicing slow riding on an AL7 and it overheated: light came on, coolant boiled out of reservoir. Nobody has yet asked him whether his cooling fan came on. It got me thinking - my cooling fan has never come on my AL7 in 17k miles/2.5 years, admittedly I do neglible town/slow riding but I don't remember it activating on my 2 curvies before that either.

Anyone here had their fan come on?
Seeker is offline   Reply With Quote
Old 20-07-18, 06:25 AM   #2
garynortheast
Member
Mega Poster
 
garynortheast's Avatar
 
Join Date: Mar 2010
Location: Mid Wales
Posts: 2,475
Default Re: Cooling fan

Mine comes on if I'm in town or slow traffic in very hot weather. Sometimes I've run the bike to get it hot for various reasons when it's been in the garage, I've run it till the fan kicks in.
garynortheast is offline   Reply With Quote
Old 20-07-18, 06:41 AM   #3
Craig380
Member
Mega Poster
 
Join Date: May 2015
Posts: 1,231
Default Re: Cooling fan

Never had mine kick in, either, in the 3 years I've owned it. The highest I've ever seen the temp gauge go was 97 or 98, I think the fan is only meant to kick in at 103C or thereabouts.

I don't do much town / commuting work at all, though, and as soon as you're doing more than 20mph it's usually enough to keep the temp from climbing.
Craig380 is offline   Reply With Quote
Old 20-07-18, 02:40 PM   #4
Bibio
Member
Mega Poster
 
Bibio's Avatar
 
Join Date: Jul 2008
Location: here as devil's advocate
Posts: 11,539
Default Re: Cooling fan

first off its an expansion tank not a rez. when the coolant gets to a certain temperature the radiator cap opens up (thermostatic valve) to allow coolant to flow into the expansion tank. when the coolant cools down there is a bleed hole in the radiator cap to allow the coolant to drain back into the radiator. any excess coolant in the expansion tank will overflow out. this is fine and you should not top your expansion tank up afterwords as its now at the correct level.

its America its hotter ambient temps than here in the UK. due to this its very very rare that your fan will kick in. to test your fan let the bike tick over till the system is 102+deg at which point the fan should kick in. the only time my fan kicks in is when i'm balancing the TB's as the bike needs to get up to 84deg before you can shut the auto idle valve off as its a twin spark so you have a small window of time to do the job before the fan kicks in and the SDS tool turn the valve back on.
Bibio is offline   Reply With Quote
Old 20-07-18, 03:10 PM   #5
Bibio
Member
Mega Poster
 
Bibio's Avatar
 
Join Date: Jul 2008
Location: here as devil's advocate
Posts: 11,539
Default Re: Cooling fan

sounds like the fan was not working then. its simple to test, just let the bike tick over till the fan kicks in. with you having the bars then i would presume that when it reaches the end of the scale the fan comes on. might tell you in your handbook.
Bibio is offline   Reply With Quote
Old 20-07-18, 03:17 PM   #6
SV650rules
Member
Mega Poster
 
Join Date: Nov 2016
Location: Shropshire UK
Posts: 1,357
Default Re: Cooling fan

Mine has never gone over 3 bars out of 6 either, guy may have had an airlock which expanded and quickly pressurised expansion tank when the pressure cap on rad opened, or maybe expansion tank was filled up too much anyway (only needs to be quarter to one third full as long as end of pipe from radiator is under the coolant so it's not sucking air back k into rad as it cools - to allow for expansion to and from radiator).
__________________
2016 SV650 AL7

Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain
SV650rules is offline   Reply With Quote
Old 22-07-18, 09:44 PM   #7
SVGrandad
Member
 
SVGrandad's Avatar
 
Join Date: Apr 2006
Location: Rugby
Posts: 98
Default Re: Cooling fan

Quote:
Originally Posted by Bibio View Post
first off its an expansion tank not a rez. when the coolant gets to a certain temperature the radiator cap opens up (thermostatic valve) to allow coolant to flow into the expansion tank. when the coolant cools down there is a bleed hole in the radiator cap to allow the coolant to drain back into the radiator. any excess coolant in the expansion tank will overflow out. this is fine and you should not top your expansion tank up afterwords as its now at the correct level.

.
My memory of cooling systems is as follows:-
The radiator cap is just a sealing cap enabling radiator filling, the thermostat just allows water to circulate around the cooling system at a preset temperature thus speeding warm-up, and the expansion tank cap should have a pressure relief valve on it to vent excess pressure to atmospere in the event of a cooling malfunction.
That is not quite what I read in the above quote.
SVGrandad
__________________
SV1000S K4, Hugger, Scottoiler. Lowers
SVGrandad is offline   Reply With Quote
Old 22-07-18, 09:58 PM   #8
glang
Member
 
Join Date: Oct 2007
Posts: 536
Default Re: Cooling fan

These are indeed two different designs of cooling systems which are used in various vehicles (modern cars now seem to use the second) however our bikes use the first type.
glang is offline   Reply With Quote
Old 22-07-18, 11:44 PM   #9
Talking Heads
Member
 
Join Date: Jan 2017
Posts: 486
Default Re: Cooling fan

Mine has never risen above three bars and I've never had the fan come on either.
Talking Heads is offline   Reply With Quote
Old 23-07-18, 07:31 AM   #10
SV650rules
Member
Mega Poster
 
Join Date: Nov 2016
Location: Shropshire UK
Posts: 1,357
Default Re: Cooling fan

The thermostat keeps the water out of the radiator and shortens the cooling loop to just water pump and cylinders to allow it to warm up faster, when water reaches a certain temp the stat opens and allows water into radiator, if water gets too hot the fan will kick in. Venting hot water to atmosphere is not done (unless you remove radiator cap when engine is hot, which releases pressure and lowers boiling point (just like kettle boils at lower temp up a mountain) one of the things coolant additives do is raise the boiling point to something like 120degC or more, because last thing you want is water boiling in a cooling system. Any expanding coolant from cooling system is routed under rad cap relief valve into expansion tank, when system cools the coolant is sucked back into main system. Cars and bikes work the same in this respect.

Venting hot coolant to atmosphere on a bike could easily result in a severely scalded right knee, but no modern system vents to atmosphere anyway, the cap seals on rad, the spring loaded valve only allows coolant access to expansion tank.
__________________
2016 SV650 AL7

Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain

Last edited by SV650rules; 23-07-18 at 07:36 AM.
SV650rules is offline   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
cooling fan monkimagic Mini-Twins 4 30-03-16 01:30 PM
cooling at the manx rvracing Mini-Twins 2 03-10-11 07:20 AM
Car cooling system. L3nny Idle Banter 12 11-12-10 11:45 PM
Too much cooling help Bonart SV Talk, Tuning & Tweaking 7 29-12-05 09:15 PM
Cooling Fan Banus SV Talk, Tuning & Tweaking 7 10-06-05 09:05 PM


All times are GMT. The time now is 01:28 PM.


Powered by vBulletin® - Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.