1985 K100 Problems w Heat Sensor - K-Bikes.com - Excellence in Motion
 
LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old Jun 14th, 2010, 10:29 pm Thread Starter
Senior Member
 
HiVizGuy's Avatar
 
Join Date: Oct 2009
Location: New Kensington, PA, USA
Posts: 123
1985 K100 Problems w Heat Sensor

Hey Guys. I've been working on my 1985 K100 all winter. I found it in someone's backyard, started it, ripped it apart, and now am putting it back together. Here is my quandry.

The temp sensor and fan BOTH come on after about 1.5 mile of riding. I've replaced the temp sensor and fan relay all with the same results. I've checked the thermostat and it is fine. It opens at 190 degrees.

One thing i am thinking.... i replaced the bulbs in my instrument cluster w LED's. Does anyone think this might change the resistance hence causing the temperature light to engage along with the fan?

FYI. I rode the bike last night in the cool Pittsburgh air (about 70 degrees). The light and fan were on for the whole trip, however the bike didn't show any signs of overheating...ie knocking, pinging, or for that matter coolant flowing out of the resevoir.

Any suggestions?

PS i have a thread under FLying Bricks titled My New Brick. Thanks

1992 R100 GS-Bumblebee
1985 K100
1975 R90/6
2003 KLR 650


www.hivizguy.com
HiVizGuy is offline  
Sponsored Links
Advertisement
 
post #2 of 5 (permalink) Old Jun 14th, 2010, 10:31 pm Thread Starter
Senior Member
 
HiVizGuy's Avatar
 
Join Date: Oct 2009
Location: New Kensington, PA, USA
Posts: 123
Temp Guage - more info

i have great flow through the radiator and we checked the impellor and it is intact and does spin when the engine is moving.

1992 R100 GS-Bumblebee
1985 K100
1975 R90/6
2003 KLR 650


www.hivizguy.com
HiVizGuy is offline  
post #3 of 5 (permalink) Old Jun 14th, 2010, 11:40 pm
Looking for better limits...
 
Razel's Avatar
 
Join Date: Jun 2003
Location: Fremont, CA, USA
Posts: 5,163
I start of with "I don't know". But, how difficult is it to put bulbs back in and test your initial question about the LED's? On the surface, it doesn't make sense, because if you had a burned-out bulb, the same condition should exist, no? On the K1200GT I have, there are two temperature sensors, one that drives the gauge, and one that drives the temp lamp. I don't know what drives the fans, but I suspect it's the same that drives the temperature gauge.

May not be much help, but that's my 2˘.



100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

Ray
2010 K1300GT Royal Blue
2003 K1200GT Orient Blue (for sale)
2007 G650 X-Challenge

IBA #34158

Be a K-Bikes Supporter

I work for Keyser Söze
Razel is offline  
Sponsored Links
Advertisement
 
post #4 of 5 (permalink) Old Jun 15th, 2010, 8:11 am
Addict
 
Join Date: Mar 2004
Location: , , UK
Posts: 3,750
......I don't know much either, never owned or ridden this model.

According to realoem parts your model only has one sensor but as Razel says, the K1200's have a separate sensor in the cyl head which connects to the ECU and it's the ECU that controls the fan relay.

My 10c of observation:

If the fans come on some time after riding then something responding to heat is probably bringing on the fan relay.

I don't think bulbs have anything to do with it, but if you dropped a wire off the gauge or lost a ground up inside the instrument cluster that might. Get a wiring diagram and trace out the path from the temp sensors to the fan relay.

Are you absolutely sure in the real world that the radiators are running cool. Idle the bike on the stand and feel the tops of the rads when the fans come on - but don't stick your pinkies in the fan! What is the temperature gauge saying. If the stat is ok as you say, then the gauge should be showing a normal temperature if the rads feel hot but not sizzling. Check the wiring diagram 'cos the gauge/sensor and fan switch may be interlinked.

Are you sure you haven't got an air lock? Again feel the point where the temp sensor is if it feels hot but not sizzling your problem is fan control. If that area does feel hot then the sensor may be telling the truth.

Obviously you now have a spare sensor and lets assume your bike only has one (But check the wiring diagram!) . Connect an ohmeter to the old sensor and dip it in frying oil. Heat up the oil from room temperature to about 120 degrees Centigrade and write down the resistance readings every 5 or 10 degrees.

Now hook your ohmeter on the bikes sensor and idle the bike. Assuming both sensors are similar, you should be able to tell us exactly what your coolant temperature is as the bike warms up and at what temperature your fans appear to be cutting in. If sensor temperature is in the 90's (deg C) and heats up very quickly then it is real and you have a plumbing problem. If the actual sensor temperature is below 70 degrees C then you probably have a wiring problem.



Never pay again for live sex! | Hot girls doing naughty stuff for free! | Chat for free!
voxmagna is offline  
post #5 of 5 (permalink) Old Jun 15th, 2010, 12:45 pm
Looking for better limits...
 
Razel's Avatar
 
Join Date: Jun 2003
Location: Fremont, CA, USA
Posts: 5,163
Another temperature discussion for the older K bikes here.



100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

Ray
2010 K1300GT Royal Blue
2003 K1200GT Orient Blue (for sale)
2007 G650 X-Challenge

IBA #34158

Be a K-Bikes Supporter

I work for Keyser Söze
Razel is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the K-Bikes.com - Excellence in Motion 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
K100 cold start problems mattinker Technical, Repair and Maintenance 7 Dec 15th, 2009 10:58 am
1985 K100 versus 2000-2002 K100 4 valve Louisiana Other K-Bikes Discussion 1 Aug 28th, 2009 9:10 am
ews & fuel sensor problems... birdymkr K12/1300R/R-Sport 7 May 10th, 2009 3:17 pm
idle problems k100 1985 gabriel Other K-Bikes Discussion 5 Feb 13th, 2008 10:25 pm
1985 K100 help endacoz Other K-Bikes Discussion 3 May 22nd, 2006 12:33 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