Assistance with 1998 K1200RS Seat Removal

[exgman]

BMW MOA Member Patrick Bulfin in the St. Louis area is requesting assistance with removal of the seat on his 1998 K1200RS motorcycle. He wrote to me in my role as MOA Consumer Liaison today, asking for assistance. His BMW dealer has not been able to help him. If any member might have some thoughts or experience with this bike and this issue, Patrick's email address is: irish5@sbcglobal.net If a member in the St. Louis area could swing by Pat's place and take a look at the bike, he'd surely appreciate your help. I'll try to find some service sources which might have some insights, but in the meantime, Pat would appreciate any and all assistance.

thanks - John Gamel

 

[lee]

Are you saying Gateway BMW was not able to remove the seat?

 

[exgman]

Lee - I looked back at Patrick Bulfin's email and here is his initial statement:

"I have a 1998 K12rs and i am unable to remove the seat.I have tried the key and it turns but the seat seems to be jammed and i tried my local BMW dealer and they were no help."

Looks like Gateway is the only dealer in that area (other is in Cape Girardeau).

 

[fmdualexhaust]

I have no idea how those seats work.
I would have someone sit on the seat to weight it down, then try turning the key.

 

[lee]

It's been too many years since having a K1200RS to remember the different things that can jam the lock.
If Gateway actually looked at it I'm surprised they could not figure it out.
Hopefully someone locally can take a look.

 

[k547]

Note: The rubber pads at the rear of the seat base fully support and bear any weight placed on the seat and the latching bar on the seat "floats" in the latch assembly and is isolated from any weight loads by the two rubber pads.
If the weight bearing pads at the rear of the seat are missing or permanently shrunk/compressed (it would be obvious with a loose, noisy, rattling seat) and the seat latching bar and seat latch are bearing weight placed at the rear of the seat that should make it virtually impossible to turn the latch with weight on it. Normally you'll want the seat "unweighted" not "weighted" to remove it but If someone replaced the two rubber pads with non BMW parts (generic rubber bumpers from Auto Zone) and the pads are taller/thicker than they should be and the seat has to be forced down to compress the pads in order to latch than conceivably you might have to weight the rear of the seat to allow free movement of the latch. You just never know what previous owners might have done to these older bikes....

I wrote this post based on my assumption that your lock cylinder is firmly seized up solid and you have exhausted all efforts to free it before taking more drastic measures like cutting things up. However the original post was pretty vague and lacking any details as to exactly why you couldn't remove the seat......
If your seat lock has just stopped turning I would spend an hour or two with some mild aerosol degreaser that won't harm your paint with a spray tube on the nozzle like the stuff in the bright orange spray can sold at Home Depot labeled "KLEAR Concepts" "Heavy Duty DEGREASER" "Quick Evaporation" "Made in the USA". Throughly spray out the interior of the lock by inserting the nozzle extension directly into the lock cylinder where the key goes. Then use some picks made of STIFF wire to probe and poke inside the lock in all directions, one pick should have a small hook or L shape bent into the business end. You will probably have to bend a larger L shape into the wire and grind or file it to size. Poke around in there up and down and side to side and spray with degreaser several times and then see if you can't get the key to turn by gently wiggling it back and forth and minutely moving it in and out at the same time. This may sound weird but I've opened simple (I mean cheap, haha, I hope our ignition locks are a better quality than these BMW seat locks) locks like this that were stuck twice before by applying a mechanical vibrator to the key or the lock body after cleaning and then twisting the key while it is vibrating.

If that doesn't work.....Plan B

I've recently (a couple months ago) had my entire seat lock assembley removed and totally dissassembled (cylinder, plug, pins, etc) and then re-installed it while "de-accessorizing" my bike and I also had my entire front/rear sections of the rear fender off and then back on the bike during my "deep cleaning" exercise. I'm going from memory here but I think that if you get under the bike and remove the rear turn signals and the rear section of the 2 piece inner rear fender you will expose this assembly which mounts the seat latch and key lock cylinder. Having the bike "lifted" and allowing the rear wheel to drop as far away from the fender as possible will give you more room to work in assuming that you don't just remove the rear wheel completly to open this area up. I looked under the fender of my bike again and I'm not 100% certain but I think it's doable to remove the rear inner fender with the seat and two rear body panels still in place.

This is BMW part number 52 53 2307799 Lock Support. The lock mounts on the far end of the tube on the right side and it is the same part on your '98 as on my '03 RS:



With the rear inner fender removed or just pushed forwards out of the way you will be viewing it (the Lock Support) from the bottom and looking up at it and seeing (nice little insect cocoon in there!) this side. The plastic shaft coming in from left to right is slotted/keyed into your seat lock on one side and the seat latch on the other side.


If you take a narrow blade Excel or X Acto hobby saw (saw blade fits into a seperate handle)


you should be able to cut thru the plastic shaft anywhere in the side or area that I have marked with the green tape here:




Once this is cut your seat latch will no longer be "locked" and you will need to grasp and rotate the yellow zinc plated latch towards the front of the bike to release the seat.


This will be very difficult to do against the modest spring pressure because of the tight space/limited access. You could always drill a hole edge on into the latch and insert a pin/nail/drill bit to use as a 'handle" and rotate it but that is probably much easier said than actually done.....
Personally, I would just get some wire cutters or a narrow cut off metal file in there and snip both sides of the springs retaining ends which are clearly exposed. Alternativly you might be able to grab the spring ends with needle nose pliers and just twist them out of place sideways and up and out thru those square/rectangular openings in the base of the Lock Support.

Here is a pic of the spring ends from the other side:



When the spring pressure is gone you should be able to easily rotate the latch and free the seat.
Once your seat is off you will need to replace the shaft you cut BMW part # 52 53 2307849 and possibly the spring which only comes with the larger Lock Support assembley (although it looks almost exactly like a Colt style AR rifle's trigger main spring which you can buy anywhere) and presumably you will want to replace your broken lock which caused all of this.
As you can see from these pics I have these parts lying around and I doubt that I will ever use them so I'm open to selling them. Beemer Boneyard sometimes has them and I've gotten stuff like this from my favorite motorcycle salvage seller in Virginia.

Once the seat is off you can drive out the retaining pin and pull the entire lock out of the Lock Support and completly dissassemble and clean and lube it and maybe not have to replace it. If you do replace the lock I may be mistaken but I think that if you very carefully dissassemble all the "plates" in your broken lock and note their order and placement and carefully rearrange the parts inside the replacement lock cylinder to exactly match them you could even use your existing key set. If not you will wind up having a seperate key for your seat.

I hope this helps and I'm hoping my memory is correct and you can get the inner fender out with the seat and rear fairing body parts in place.
In any case this will be a fussy/frustrating little job working upsidedown.