Must KLR fan run all the time to avoid overheating? - Kawasaki KLR 650 Forum
2008+ KLR650 Wrenching & Mod Questions For repair, maintaining or modifying discussions related to the newly updated 2008 and beyond, Generation 2 KLR650 Motorcycle.

 1Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 29 Old 05-17-2016, 12:38 PM Thread Starter
2nd Gear
 
clogan's Avatar
 
Join Date: Dec 2010
Location: Tennessee
Posts: 324
Question Must KLR fan run all the time to avoid overheating?

I just finished a 685 kit install, and now my bike overheats. It seems fan switch may be bad, since fan does not want to come on. I put a little jumper on the switch, and the fan runs fine. Gonna test the switch in a pot of hot water as soon as engine cools a bit.

But here's my real question: should the fan be needed 100% of time in order to avoid overheating? I rode 5 miles today with all plastics off, and temp gauge headed toward the red if the fan was not on. No idling, no traffic, speeds of 30-40 mph, and air temperature of 65 degrees. But when I added the jumper, and forced the fan to come on, the temp needle stayed horizontal for the next 5 miles. This is in the "normal" range, but certainly hotter than I would have expected on such a cool day, with all plastics off.

I've got good flow in my radiator, and I've burped the system of air pockets. Kit was from Eagle Mike. I also just now replaced my thermostat thinking that was contributing to the problem, but now it looks like the fan switch. (Hope not: a new one is >$100.00!!

"Chet from Chattanooga"
2009 KLR, blue

Last edited by clogan; 05-17-2016 at 12:49 PM.
clogan is offline  
Sponsored Links
Advertisement
 
post #2 of 29 Old 05-17-2016, 02:21 PM
2nd Gear
 
Join Date: May 2016
Posts: 171
my cooling needle is always VERY LOW, and a tad higher than COLD on highways
im in southern california, so weather is pretty warm.

the needle hits little over the middle when doing lots of offroading, slow speeding, running on first gear most of the time for hours.

CURRENT BIKES:
2013 KLR650
2016 BMW 1200GS ADVENTURE
2015 HARLEY DAVIDSON SOFTAIL SLIM
2009 KLX250
PRE-BIKES:
2015 VULCAN S
2008 YAMAHA FZ6
2006 NINJA 250
2009 SUZUKI BURGMAN 400
2012 HD IRON 883
xzatx is offline  
post #3 of 29 Old 05-17-2016, 02:22 PM
2nd Gear
 
Join Date: May 2016
Posts: 171
i did however hear that previous model of klrs had overheating issues and the new ones have bigger cooling systems, mine is 2013.
im not sure if that is correct.

CURRENT BIKES:
2013 KLR650
2016 BMW 1200GS ADVENTURE
2015 HARLEY DAVIDSON SOFTAIL SLIM
2009 KLX250
PRE-BIKES:
2015 VULCAN S
2008 YAMAHA FZ6
2006 NINJA 250
2009 SUZUKI BURGMAN 400
2012 HD IRON 883
xzatx is offline  
 
post #4 of 29 Old 05-17-2016, 02:22 PM
5th Gear
 
Join Date: Jan 2011
Posts: 4,332
Quote:
I just finished a 685 kit install, and now my bike overheats.
Define, "overheats." If your coolant doesn't boil, and the temperature gauge stays out of the far right red zone, that's not overheating, IMHO. Yet, the cooling system should stabilize coolant temperature somewhat less than such an extreme.

Fan should NOT run continually; only activated when coolant in bottom of radiator exceeds 201 degrees F., activating thermal switch. I'd expect a continually operating fan to have a limited service life.

From your post above, understand your thermal switch never closes, regardless of temperature.

Does coolant temperature gauge ever stabilize at a point lower than the far right red zone, without manual activation of fan (e.g., when riding in cool ambient temperature)? If not, a coolant circulation problem may exist.

Otherwise, I've experienced no cooling problems with my Generation 1, with operational thermal fan switch.

Last edited by Damocles; 05-17-2016 at 02:31 PM.
Damocles is online now  
post #5 of 29 Old 05-17-2016, 02:30 PM Thread Starter
2nd Gear
 
clogan's Avatar
 
Join Date: Dec 2010
Location: Tennessee
Posts: 324
Mine is a 2009, so the red area is at top of gauge, not on the right. Anyhow, with fan running, needle settles at horizontal, or half way to the red. With no fan, needle goes to red. But by then, bike has already stalled. I try to avoid that.
clogan is offline  
post #6 of 29 Old 05-17-2016, 03:53 PM
Pretty in Pink, dunno why
 
Tom Schmitz's Avatar
 
Join Date: Feb 2009
Location: Redondo Beach
Posts: 7,572
Garage
Do you have a Thermo-Bob installed?

Make sure that you didn't incorrectly connect the inlet and outlet hoses to the water pump. It's easy to do.

Make sure that the hose that is on the nipple that is labeled "Cyl" goes to the front of the cylinder, not to the radiator.

If they are crossed up then the coolant will not circulate with a T-Bob installed. Not sure how it would affect a system with no T-Bob.

If you don't have a T-Bob, then I'd suspect some blockage somewhere, either from an air pocket or debris. Might consider removing the elbow from the front of the cylinder and see what comes out.

If the bike is in motion then fan will seldom, if ever, come on unless the ambients are in the 100 degree range.

Let us know.

Tom

Tom [email protected]

“She went out slowly. The way she did it hadn’t been learned at business college.” -Philip Marlowe

“'Why' and 'How' are words so important they cannot be too often used.” -Napoleon Bonaparte


Sting like a butterfly.

Last edited by Tom Schmitz; 05-17-2016 at 03:55 PM.
Tom Schmitz is offline  
post #7 of 29 Old 05-17-2016, 04:27 PM
OverDrive
 
Join Date: Nov 2009
Location: Lander, Wyoming
Posts: 5,540
clogan,
Did you have the water pump cover / clutch cover off during this rebuild?

If so, I'm guessing that you left the water pump nut loose! Your circulation is not as swift as needed.

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 85,000+ miles & counting
pdwestman is offline  
post #8 of 29 Old 05-17-2016, 04:56 PM Thread Starter
2nd Gear
 
clogan's Avatar
 
Join Date: Dec 2010
Location: Tennessee
Posts: 324
Did not have water pump cover off. By overheating, I mean needle pegs to red area, engine locks up/stalls/dies (three instances), and coolant spews out overflow under rear fender (first instance only). Hoses to radiator were cris crossed for first instance, but then corrected. Last two overheating instances had hoses oriented correctly.
clogan is offline  
post #9 of 29 Old 05-17-2016, 05:40 PM
Pretty in Pink, dunno why
 
Tom Schmitz's Avatar
 
Join Date: Feb 2009
Location: Redondo Beach
Posts: 7,572
Garage
Wellll, it's physics. If the coolant circulates then the engine doesn't overheat.

I'd heed Paul's suggestion and remove the pump cover just to make sure it's all good. Bump the engine and see it turn.

After that, I think you're looking for blockage of some sort, so you might want to pull the hoses and make sure they are clear. Remove the cylinder nipple and make sure there's nothing blocked in it or in the base of the cylinder. Pour water in the top of the radiator and watch it fall out the bottom. Remove the T-Stat and pour water in and watch it run out the bottom of the cylinder.

It's tedious, but you'll find it. The key is to see things work as they should, one piece at a time.

Tom
gruet782 likes this.

Tom [email protected]

“She went out slowly. The way she did it hadn’t been learned at business college.” -Philip Marlowe

“'Why' and 'How' are words so important they cannot be too often used.” -Napoleon Bonaparte


Sting like a butterfly.
Tom Schmitz is offline  
post #10 of 29 Old 05-17-2016, 06:28 PM Thread Starter
2nd Gear
 
clogan's Avatar
 
Join Date: Dec 2010
Location: Tennessee
Posts: 324
Thanks, Tom, Paul, everyone. Gotta take it a step at a time. Good outline, Tom. That's what Ill do when I next can get to it. Soon as I find the point at which water doesn't flow, Ill know where the blockage is.
clogan is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki KLR 650 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Split type lockwashers- avoid them! Normk How To's & Tech Guides 9 07-08-2014 04:32 AM
KLR 600 Fan and Ignition wiring Millhouse Other KLR's - 250, 600, Tengai, C Models, KLX... 14 08-06-2013 09:12 PM
Mi 3 KLR Run Dfrog The Off Topic Lounge 0 03-25-2008 04:23 PM
My klr run Dfrog The Off Topic Lounge 6 02-09-2008 09:11 AM

Posting Rules  
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome