K11 Owners Group

[rg500g]

I worked with various foam elements and fairly well sealed up the area around the rear of the gas tank. I took the bike for a ride, and at the end of the ride still had a hot spot. The tank itself is getting hot. When the prior owner painted the bike, either he removed insulation under the tank or it was never there. The tank itself is getting quite hot.

I've reviewed a number of parts fiches online, and for the '93 model year no fiche shows a part number for the insulating panels under the tank. I can see the three panels for the K100 RS 4V engines and I'd assume them to be suitable (not sure though) and there's this gasket. The link I'm using is:

http://www.realoem.com/bmw/showparts.do?model=0532&mospid=47928&btnr=16_0242&hg=16&fg=05

Part #s 6,7,8, and 16 are what interest me, and part #16 is the gasket I referenced above. I'd greatly appreciate it if anyone can clarify this for me so that I can get this heat management issue under control. I don't like getting burns while riding the bike.

[Rider]

The installation of those parts certainly would help reduce the amount of radiant heat from the engine as well as the hot air blast from the radiator. I would also suggest insulating the fuel rail too. The fuel circulates through that plumbing and back to the tank constantly. Some time on a hot day fill the tank and see how long it takes for the fuel to heat up. Good luck with the project.

Ed
_________________
2007 650 Burgman, 2003 400 Burgman


Some days you get the bear, some days the bear gets you.

[duckbubbles]

Anything you can do to insulate/isolate the fuel lines behind the radiator will help reduce the heat. You might try an automotive interior shop for some sticky backed foil aluminum insulation for the underside of the tank. Cut to appropriate size an installed will help and cost less and be quicker to get than the original stuff, and will work as well.

I rearranged the routing of my fuel hoses on my '85. They run further to the rear and allow me to set the tank back where the seat goes without disconnecting them from the tank.

BMW used to offer tank knee pads that fit in the indentations in the aft portion of the tank. I used to have a set on my bike and they did work very well. They were about 1/2 inch thick.

All these methods helped my bike, but not letting the fuel level drop too low also kept the heat under control.

Frank
_________________
85 K100/1100RS, 321,000 miles, 25 years
96 Ducati 900SS/SP, sold it
05 R1200ST, 35,000 miles, 5 years
400,000 BMW miles

[rg500g]

What I really need to know is, whether or not the parts shown in the link I provided in my original post are valid for a '93 K1100RS. I'm looking for someone who has a '93 K1100RS who can tell me if they have some insulating panels on the underside of their gas tank or not, and whether or not there is this funny looking rubber thing that's under the tank that's held to the frame with a couple of hose clamps. I don't want to order these part numbers then find that Teutonic engineering wisdom took a different tack between when these parts were specified in the model, and my model's year, invalidating them due to fouling other wiring under the tank, etc. I know what's good to do - I need to know if some specific parts are originally supposed to be on my bike or not.

[abreeze]

I covered all the fuel lines and fuel rail with pipe insulator(yeah the cheap stuff at the hardware store)..the closed loop fuel circulates and is heated by the hot air under the tank..

Aircraft Spruce has an aviation grade firewall insulation that I used to cover the airbox, throtle bodies and every other place that i could. essentially wraping the area.

Works like a charm.

[max]

Hey - Duck has one of the #16s on his site for sale, $5... They should fit, but probably won't do anything - the early Ks had plastic cover plates that clipped in either side of the headstock, so you didn't get much air directed in under the tank from around the headstock - 1100s don't have that, so there would still be airflow coming from the front, even if less "hot stuff" possibly from the sides.

On the main point, and not wanting to sound like a smart-ass, but have you tried wiring up a manual fan switch yet, just to check whether getting the heat **out** (of the bike) would help? Even a temporary try - pull the fan relay, jumper its load contacts, that will turn on the fan - might help, might give you an idea of whether using the fan can take off the sharp edge of the top of the heat curve by never letting it get up there... It might be capable of being an overall, fast fix (either by putting it on a switch, or as via a ballast resistor) without taking too long or stressing over airflow paths...

Do have a search on hot-wiring the fan if that experiment helps - I've got mine going at about 25% continuously through ballast resistors (home made) and I barely get above 1/2 way on the dial with in-town riding in 32degC weather... a couple of the Aussies are using the fan too, it does make a BIG difference, the heat can't build up, let alone build up in the faring (and the outlet stream is warm, not scorching either).

HTH

Max

[rg500g]

I have not considered a manual switch, but I can see merit in it. I'm going to go ahead and see what the BMW insulating sheets cost. I need to keep heat away from the underside of the tank, and the only way to do that is to directly insulate the underside of the tank. OTOH I've got a lot of foil faced fiberglass insulation left over from the same sort of job I did on the gas tank of my RG500, and I may just use it instead. I'm cautious of the clearance between the tank underside and the frame/wiring though, and don't want to create a scuff point.

[Technician]

There are three foil insulating panels available to attach to the underside of the tank. These are self adhesive fibre[insulation] with a foil front and the part no's are.
16 11 1 455 104 large/main panel cost me approx £ 9.00 about a month ago
16 11 1 453 067 side panel
16 11 1 453 068 side panel

Hope this is of help.
_________________
Fat Ba***d with a K1100LTse
Squire D18 trailer
Garmin Zumo 660
"Run it round the block to see if the wheels fall off!!!!"

[biblek]

[Jim]

hi Kenan - the original info is here: http://www.k11og.org/forum/viewtopic.php?t=2414&highlight=ballast and here: http://www.k11og.org/forum/viewtopic.php?t=1764&highlight=ballast

The search button at the top of every page is your friend.
_________________
Jim
1997 K1100LTSE 94,000 - still has gremlins!
1995 R100RT Classic 16,650 crashed - repaired!
1992 K75RTP 46,000

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

[biblek]

Jim,
Thank you very much! I did install a switch over the weekend that allows me to run the fan anytime (information from this site). I would like to use the resistors and have a 2 position switch so I can run the fan at two speeds.

I really like this forum and appreciate all of the information from everyone.

Thanks again,
Kenan

[jimbenge]

I also have a 93 K1100RS, have had it for years and diden't ride it in the summer because it was toooo HOT ? After reading several threads in this forum I put a K100 radiator in the K1100 and the fan switch mod. The fan switch mod is OK but the real fix for me was the radiator. The stock K1100 radiator is only 2 cores thick, the K100 radiator is 3 cores thick (1/3 more radiator). Who knows why BMW did this is beyond me, and the fairing on the K1100RS is much more air restrictive than any other model. Anyway, the radiator swap is an easy direct replacement, the fan has to be slighly modified to fit. If you do a search I am sure you can find some pictures on the mod in this forum. I live in San Diego and have to cross deserts to get out of town and the radiator was the only thing that worked.
_________________
Jim Benge, San Diego, CA.

1995 K1100LT
1993 K1100RS & Getaway trailer
K100RT with 1985 EML sidecar & Kwik-Kamp Trailer
2006 Harley 1200R Sportster