k75 front suspension questions

thanks to the encouragement and tips i received here last month, i
completed the drive shaft and clutch spline lubes without a hitch. so i
thought i'd push my luck with some questions about the front suspension
on my '92 k75s.

i've mentioned before that it takes bumps remarkably hard (even bottoming
out at times, i believe.) according to the records of the guy who had
the thing before i did, he had the fork springs (along with the seals,
spacers, et al) changed a little less than a year ago and the bike's been
ridden less than a thousand miles since.

per advice offered here previously, i'd like to start the troubleshooting
by changing the fork oil. unfortunately i've noticed that the thing is
leaking oil onto both forks at the top of the sliders. so i feel like i
ought to replace the fork oil seals before changing the oil.

further complicating things, the leak and the rough handling are making
me wonder if the mechanic installed the forks correctly. this and
previous events with different shops have brought me to the point where,
unless i do the work myself, i'll be plagued with doubts that the work
has been done right. so now i'm thinking about dismantling, inspecting,
and reinstalling the forks.

problem is, i don't know what the hell i'm doing. i've taken a cursory
look at the clymer's guide and gathered the impression that it's not too
complicated. on the other hand, i also looked at randy g's fork
alignment treatise (see Duane Ausherman's BMW website,) and it convinced
me that i have neither the facilities, tools, nor know-how for the job.

in any event, my goals are (a) to make sure the forks are assembled and
operating correctly, (b) to change the fork oil, and (c) to change the
fork oil seals. with that in my mind, here are my questions:

#1: if i take the forks off the bike, how difficult is it to get them
back on properly? i don't understand or have the tools to do all that i
saw in randy g's patient, well organized explanation. should i just take
it in to a new mechanic? if so, can you recommend someone in san
francisco?

#2: in case you encourage me to do this myself, what oil should i use?
are they any parts (other than the oil seals) i ought to replace while
i'm there.

#3: any other tips?

also: i should probably have mentioned that i'm not sure if the forks
are stock or aftermarket.

all input appreciated.

 

If it is bottoming out, then it could be as simple as the fork oil being
low. If the fork seals are blown, this is fairly likely. The good news,
is that if the leak is bad enough, it will eliminate brake squeal. Before
ripping the forks to pieces(or having it done) I'd get the seals replaced,
and the oil refilled to spec. If the seals blow again, you've probably got
pitted forks(fairly common, which is why you see lots of K75s with R-bike
fork gaiters on). If the forks are pitted you can try running a heavier
weight oil, that kept my seals from blowing until I had the forks
replaced(due to a minivan incident)

From your earlier posting, I thought your hard ride was referring to a too
hard suspension setting, but now it sounds too soft.