K11 Owners Group

hockeyshifter

When OEM parts fail i always try and determine WHY. The cooling fan motor for the K bikes is a typical GERMAN and over enginered.. i will explain with pictures

[img]https://photos.google.com/photo/AF1QipOrqFyQGtcmKJ3c-qNLvVWsrLGAG889Z0qTyw6V[/img]

in this picture you can see that the plastic arm holding the contact brush melted. this was because as the motor gets older the corrosion increases which eventual seizes the armature and the current flowing causes an over heating.

[img]https://photos.google.com/photo/AF1QipOywJcemhu8Cz3eshkHVR-EE76LJygS8Zma3hgf[/img]

you can see this design is a poor choice because of two faults. first is the needed clearance to make the motor function as this ages contaminates will enter the housing and adhere to the magnets increasing friction and causing the motor to spin slower while increasing amp draw. the second is the the location and the amount of heat it is exposed to which causes large amounts of metal components to expand and contract over the years which will lead to failure..HEAT KILLS ELECTRICAL COMPONENTS and the lack of cooling air to reduce the heat the motor is exposed to . this bike was really designed to run in cooler climates not the mid-atalnitc or souther USA..

[img]https://photos.google.com/photo/AF1QipPoaDfZOd7QL0dKU3SwqBU-JfXzDdeOGhNUAgok[/img]

NO GD BEARINGS FRONT OR REAR.. the lack of a sealed support bearing that would take the load.. a simple sleeve bearing that is exposed ( yes even in a cover ) will not hold up to dirt and grime.

i would suggest looking at alternative cooling fans that will take the heat, be better at removing the heat... , and hold up over time ..

the single biggest problem with the RS platform is the fact that the faring and kneepads actuall confine the heat and the radiator is undersized for what it must do..
_________________
fix the problem not the blame ; fix what is messed up ; NO one is to blame.

Flying Duck · Posted: Sat Oct 12, 2019 10:44 pm Post subject:

The problem with the K design is that there's no place for heat to go. You could have the greatest fan in the world and it would just do a better job of pushing heat into the small space enclosed by the air box on one side, the plenum above the throttle bodies on the other side and the relay box. This puts a lot of heat onto the bottom of the gas tank. What heat does escape goes to the rider's thighs.

I like SPAL fans:
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/fans/fans.htm
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

flybd5 · Posted: Sun Oct 13, 2019 11:54 am Post subject:

Why not make it so the hot air has a place to go by closing the back of the fan, ducting the hot air out the sides and down, and shrouding the rest of the radiator to match? This could also be done by removing the single large radiator fan and installing two smaller ones with ducting down and out.

I used to build BD-5 kit aircraft, and engine cooling was always a huge PITA because the engine lives inside the fuselage. Most builders just didn't understand what to do about engine overheating, particularly on the ground.

I learned long ago that cooling an engine is not about how much air goes through a radiator and/or piston cooling fins, but about how much hot air is taken away by the flow. The best design for the various engines that people adapted to that little kit aircraft were those which utilized a concept very similar to the cooling system on P-51. A scoop pulls cool air into the engine compartment, and then out the tail through a duct that decreases in volume as it reaches back, forcing the air to speed up and out. The airflow keeps the hot air moving out, and if necessary can be assisted with a small fan.

_________________
To err once is human. To do so repeatedly is incompetence.
1995 K1100LT SE

Flying Duck · Posted: Sun Oct 13, 2019 6:39 pm Post subject:

I don't know the details but back when K1100LTs were used as camera motos on Tour de France they equipped them with two radiator fans.

_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

flybd5 · Posted: Mon Oct 14, 2019 4:42 am Post subject:

I'm surprised I can't find a single pic of that setup on the web. One would think a mod like that would have been given *some* publicity... Then again, it shouldn't be too difficult to whip up a frame that uses the stock mounting holes to mount two low-profile fans.
_________________
To err once is human. To do so repeatedly is incompetence.
1995 K1100LT SE

Flying Duck · Posted: Mon Oct 14, 2019 7:04 am Post subject:

Al Gore hadn't invented The Internet yet back when that was done.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

flybd5 · Posted: Mon Oct 14, 2019 7:10 am Post subject:

The World Wide Web opened to the public two years before the first K11's rolled off the assembly line and well after Gore promoted the legislation to expand Arpanet. Smile

This project is interesting. I'm going to look into sourcing the parts and developing the engineering for the mod.
_________________
To err once is human. To do so repeatedly is incompetence.
1995 K1100LT SE

N41EF · Posted: Mon Oct 14, 2019 4:12 pm Post subject:

I used a lower temp thermostat to lower the normal operating temperature. 170 degrees and it worked great. That doesn't help with he fan issue, but in normal riding when the fan isn't running, the air blowing on the riders knees is "only" 170 instead of 195.
_________________
2014 R1200RT Water Cooled
2001 R1100S Light
1993 K1100LT. Nissan Ice Blue.(Gone)

flybd5 · Posted: Tue Oct 15, 2019 3:42 am Post subject:

That's a good idea.
_________________
To err once is human. To do so repeatedly is incompetence.
1995 K1100LT SE

flybd5 · Posted: Tue Oct 15, 2019 4:53 am Post subject:

Flying Duck · Posted: Tue Oct 15, 2019 8:35 am Post subject:

I solved the heat problem inadvertently. My Motoport Kevlar jeans have thigh armor that keeps my thighs from getting cooked. (Moderately thick leather riding pants also do a decent job of insulating thighs from engine heat.)

Highway pegs on the LT engine bars also help,
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

flybd5 · Posted: Tue Oct 15, 2019 8:36 am Post subject:

LOL!

_________________
To err once is human. To do so repeatedly is incompetence.
1995 K1100LT SE

N41EF · Posted: Tue Oct 15, 2019 1:39 pm Post subject:

Post 5 of this thread has the part number.

http://www.k11og.org/forum/viewtopic.php?t=12179&highlight=thermostat

I ran that thermostat for two years and had no issues. The ECM will adapt to the lower temperature after a tank or so of fuel.
_________________
2014 R1200RT Water Cooled
2001 R1100S Light
1993 K1100LT. Nissan Ice Blue.(Gone)

flybd5 · Posted: Tue Oct 15, 2019 2:02 pm Post subject:

Unfortunately that part number (7214-170) no longer exists in their catalog or web site. Do you remember what was the application? I think you said Nissan, but which model?
_________________
To err once is human. To do so repeatedly is incompetence.
1995 K1100LT SE

flybd5 · Posted: Tue Oct 15, 2019 2:03 pm Post subject:

Unfortunately that part number (7214-170) no longer exists in their catalog or web site. Do you remember what was the application? I think you said Nissan, but which model?
_________________
To err once is human. To do so repeatedly is incompetence.
1995 K1100LT SE

flybd5 · Posted: Tue Oct 15, 2019 2:18 pm Post subject:

BTW, when I posted that last message I got this:

General Error
Could not obtain topic watch information
DEBUG MODE
SQL Error : 2006 MySQL server has gone away
SELECT topic_id FROM phpbb_topics_watch WHERE topic_id = 13332 AND user_id = 3019
Line : 687
File : functions_post.php

MySQL server has gone away is usually bad news. Smile

_________________
To err once is human. To do so repeatedly is incompetence.
1995 K1100LT SE

N41EF · Posted: Tue Oct 15, 2019 2:29 pm Post subject:

https://www.amazon.com/Motorad-7214-170JV-Fail-Safe-Thermostat/dp/B000C5E9U0

That is a motored part number. the last three numbers are the temperature that the thermostat is supposed to be open. Fail safe means the thermostat is spring loaded so it fails open.

I did a google search for 7214 thermostat and several part numbers pop up from 195 degrees to 160. Looks like a Toyota Rav4 is listed buy I'm not sure.

You should be able to get one at any parts place (or on-line) although I had to order mine, they don't normally stock this cold of thermostat.
_________________
2014 R1200RT Water Cooled
2001 R1100S Light
1993 K1100LT. Nissan Ice Blue.(Gone)

flybd5 · Posted: Tue Oct 15, 2019 2:40 pm Post subject:

Sweet. Thanks. And for the first time EVER, I can order something from Amazon.Com for shipping to Germany for a fraction of what it costs in Europe. The Amazon UK site stocks it for a whopping 59 pounds sterling, or $75. Only $12 with shipping and import duties to Germany from the US site. Smile

_________________
To err once is human. To do so repeatedly is incompetence.
1995 K1100LT SE

hockeyshifter · Posted: Sun Oct 20, 2019 3:45 pm Post subject:

FLYBD5 ... you are absolutely correct about the heat issues with aircraft and they do apply this K11 design... you could ( in theory) double the surface area of the radiator and still over heat the unit.. some people have removed the side skirts during the summer but to little effect.. what i will be doing next year will be to remove the knee pads sections which will allow all the heat to escape upwards while switching the cooling fan to always on...

on a side note during WW2 some of the multi-bank radial engines used in germany and america were prone to overheating during taxiing and slow/ low speed manuavers .. even with the advent of cowling flaps and a pusher fan ( fw190) it was still a problem..
_________________
fix the problem not the blame ; fix what is messed up ; NO one is to blame.

Jim · Posted: Mon Oct 28, 2019 1:15 pm Post subject:

More info about lower temp thermostats:

http://www.tuneruniversity.com/blog/2012/04/low-temp-thermostats-whats-the-advantage/

Or, why not leave well enough alone?
_________________
Jim
1997 K1100LTSE 94,000 - has gremlins!
1995 R100RT Classic 16,650 crashed - repairing
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."