I am buying a 99 K1200LT with 54k on it. The bike looks pretty clean. They put new front fork seals in it and few other things. No evidence of oil leaks and it passes the NH State inspection which is pretty rigorous. I don't have the bike's history. After wallowing around in the forums, I have read a lot about the failure in the FD. Should I be worried about it failing in this bike? Is it best to change it out after xxxxx miles or if it ain't broke, don't fix it? From what I have read, as long as I keep up with maintenance this beast should last me awhile. I have been reviewing the excellent you tube vids on Face Book from the Illinois club. I am not bothered by the head light. Are there any suspension issues I should think about? My current ride is a 86 Yamaha Venture Royale, so I am used to running a big, top heavy bike. I'm a big lad at 6'2, 245 so that does not bother me. I can run a wrench but I am not joe mechanic. Any guidance would be appreciated.
Welcome to the forum Jim. The not quite Random number that i have seen floating around is around 4% of these final drives have failed prematurely. With no history, you have no idea if yours has failed previously and already been repaired or if it may be one of those that is yet to fail. There are several things that can fail or cause issues in the FD mainly the crown bearing and that will certainly ruin your day. If you can grab the wheel at 12 and 6 and rock it back and forth with no discernible play, they it probably isn't in the process of failing. The preload of the inner bearing is only 2 to 4 thousandths of an inch so not very much. It isn't a great test for the FD condition but without disassemble and inspection, there really isn't much else you can do.
First thing I would do is a full fluid change paying very close attention to the magnets on the FD and transmission. The job isn't too hard to do but the tranny drain plug can be tough unless you have the right tool. A cut off piece of allen wrench and a box wrench over it is what I use not removing the center stand and that will get oil on it as it drains. I just clean it off when done.
If you pull the FD plug and find metal flakes on it, then the bearing is in the process of failing. Normal oily gray very fine metal powder is OK but anything larger is cause for concern.
Kirk did an excellent job on his videos and they are a must watch for all LT owners especially how to lift it if she takes a nap.
Look through his videos and find the one that talks about the jack oil fairies. Never seen one but they must exist because the oil in the rear shock load adjuster seems to disappear with no trace. Do the test in backing it all the way out and then see how far you have to crank it in before you start getting any resistance. if you have to go beyond the bottom line, then go ahead and fill it back up as he does in the video. Makes a big difference in the bike.
Probably the biggest safety upgrade/repair is those 15 year old brake lines. If they are original, they are going to burst soon and may cause you severe injury depending on how and when they go. The defacto standard is Spiegler braided stainless lines anthough some have gone to the trouble of removing the old ones and taking them to a local hydraulic shop and having them remade.
Here is the link to the Spiegler site. Some dealers carry these kits and i have heard you can get colors for the same as the no color price but I don't have those links.
The other things you may have read about are the clutch slave cylinder leaking into the clutch and the main clutch housing O-ring seal getting old and cracking leaking into the clutch housing and also contaminating the clutch. There are weep holes that can be drilled to allow early detection of these issues. Watch jzellers weep hole videos so you can try and look to see if those have been done indicating that some of those items may have already been serviced. The presence of those are no guarantee that anything was replaced. The upgrade of the clutch housing O-ring is a Viton over stock rubber compound for your reference if needed in the future. You can drill the clutch housing weep hole with no disassemble. If you get oil out, then you have an issue that needs to be looked at. Some disassemble required for the slave cylinder weep hole.
Welcome and i hope you get many enjoyable miles out of it.