How to remove the cooling fan assembly

[Wheezyryder]

Hello all. I'm still in the process of getting my early '85 K100 roadworthy. Bought it a couple months ago and have been steadily making progress. Finally got the fuel leak at the sender unit fixed (I posted about that last month) and have been able to take the bike out for a ride. Runs, idles, shifts and brakes great. I have a few electrical gremlins that I'm working on (brake lights, turn signals, speedo). But the biggest issue right now is that if sits idling at a stoplight for a while, the coolant temp warning light comes on (my bike doesn't have a gauge just the warning light).

I figured out that the cooling fan wasn't turning on. and in the process of troubleshooting, discovered that the fan is kaput. I removed the radiator/fan assembly from the bike, put 12v and ground to the connector and at first it didn't spin at all. With a little manual turning I got it to kick on intermittently. Also, 2 of the fan blades are broken off. So I did a bit of research on this site and decided to install the Spal fan. Got it in the mail today.

My question is...How do I remove the top rubber mount that attaches the fan housing to the radiator? The bottom 2 mounts attach with screws, but I can't figure out how to remove this one. From what I understand about mounting the Spal, most folks cut the factory fan housing arms and rivet them to the Spal housing. So I need this thing to come out in one piece.

[Wheezyryder]

Fan/radiator assembly

[The Mighty Gryphon]

There is a metal insert in the rubber grommet.  Push it out and the grommet can be removed.  If it doesn't want to come out, a little liquid soap can make it a bit easier.

BTW, are those fins as funky as they look in the photos?  When you flush them, do it from the backside(where the fan is).

[Wheezyryder]

Thanks Gryphon! That was just the hint I needed. The metal insert in mine is split in the middle. Pulled the 2 halves out with the help of a little WD40. Then pushed the insert out with a punch. That probably would've taken me a while to figure out.

[The Mighty Gryphon]

 

Did you find the thread on the Spal retrofit?

[Wheezyryder]

I've found a couple of different posts about how to install the Spal. I'm about to walk out to the shop and stare at it for a while. Try to decide if I want to cut and reuse the original fan housing or make a new bracket. I'm definitely open to suggestions.

[The Mighty Gryphon]

There is a thread from about 2015 that describes using the old housing by removing the old fan and putting the Spal in it's place using pop rivets to hold it together.  No special bracket is necessary so you can whack things together in about two hours or less.

This should help:

http://www.motobrick.com/index.php/topic,4313.0.html

The good stuff starts at reply #18.

[Laitch]

Here's fan replacement from a slightly different angle.

[Wheezyryder]

After looking at it for a bit I decided to cut the factory fan mount and use rivet/silicone it to the Spal fan. I think it'll be fairly fast, sturdy, easy and best of all...free. Which is good because I just dropped a bunch of coin for the parts to rebuild the oil/water pump. Hopefully after I get the fan installed and the oil/water pump rebuilt I'll be ready to ride this thing further than just around the corner. Then on to chasing electrical gremlins.

Thanks for the help/suggestions Gryphon and Laitch!

[The Mighty Gryphon]

Good choice.  The one I did is still going strong even after most of the bike around it was totalled when it was the victim of a rather serious vehicular assault.