I'm probably approaching 100 mods on each of my Gen1 KLR's.... I would suggest that desireablity depends on the individual, thier wants, needs, expectation, usage and budget. For ME, my KLR's are toys for exploring and due to my offroad racing background, I enjoy mild to moderate single track riding the most. I don't do multiday trips, nor do I ride on the highway much if I can avoid it.....accordingly my mods are different than people with a different mission.
To go further, I'd say mods can be broken down into a few catagories; 1) reliability 2) protection 3) comfort/ergos and 4) functionality.......not necessarily in that order.
- the doohickey is a "must do" on a Gen1 IMO.....it is far easier to do before it breaks into little bits than after so there is no better time than the present
- other than that, there is regular maintenance, checking shim clearance etc.
- I have removed some known failure points but that's up to each rider and their comfort level....I've removed the sidestand and clutch safety switches, the vacuum petcock and gas cap vent seals (I run an IMS tank).
- I have swapped to ATO style fuses
- I have replaced the upper subframe bolts with Eaglemike kits (particularly desireable if you are going to carry heavy panniers or ride 2 up often)
- T-mod on the carb vent to prevent rain or a creek crossing from halting your ride
- a Thermobob improves cooling system operation and will enhance longevity.
- replacement of the factory plastic skidplate is fairly important for offroad use; I use the Ricochet but the JNS is also highly recommended
- decent bars (this is also a comfort/ergo issue) as the stockers are very weak IME
- hand guards - a necessity in the trails around here
- crash bars or equivalent - I use an IMS 6.6 gallon tank and a set of JNS rad guards for protection without the weight.
- I run Eaglemike's choke/mirror relocation kit as it's only a matter of time before a fall brakes the mirror mount on the switchgear
- I replace the rear brake master bracket with a billet pce from Eaglemike as the stocker is known to be brittle
- I run low profile magnetic drain plugs so as not to damage the case on a rock.
- aftermarket bars - the stockers have way too much pullback. I use Renthal RC-Hi's
- drop pegs or peg relocation brackets - the stock pegs are too far forward and too high which gets worse when you replace the footpegs with proper offroad worthy footpegs. People often get longer shift levers instead but they stick out farther and increase the risk of case damage
- proper offroad style footpegs with springs (see above)
- bar risers - people use them more often than they should IMO. One issue to be aware of is that the bar mounts on a KLR are tilted backwards and so fixed risers bring the bars towards your body which is a bad thing.....adjustable risers such as Rox Risers pivot away to help with this issue.
- suspension is the biggest weakness of a stock KLR, especially for offroad use. Suspension is a whole other involved topic so all I'll say here is that out of all the mods I've done, suspension upgrades have made the single biggest functional improvement by an entire order of magnitude. I run Cogent Dynamics DDC kits in my forks and one of their three shock choices in the rear. I can expand on the whole topic in greater detail if you wish. Stock Gen1 KLR suspension is old tech damper rod forks and a budget emulsion shock set up for the (largly mythical) 160lb rider.
- front brake - I find the stock KLR front brake to be dismal at best - I run 320mm rotors and SV calipers/adaptors along with a SS line which vastly improves the bikes braking power
- visablity/lighting; stock lighting is poor - I run JNS LED headlights and WOW LED taillights which work much better, take less electrical power and are way safer and brighter
- tires - last, but not least, the stock dunlops are poor - I run Pirelli MT21's on the front and Dunlop D606 rears for what I do.....big improvement
I'm sure I've forgotten some stuff and I've done a ton of other mods to make my bikes better but I wouldn't consider them priorities;
- KLX jet kits correct the factory lean jetting
- LiFePo4 batteries save 9 lbs
- aftermarket silencers, save another 5 lbs (beware that some are way too loud and you need to make sure it still has a USFS spark arrestor)
- 685 kit; reduces vibes, fixes oil consumption issues and boosts power
- IMS tanks; improves ergos, range, reduces weight compared to crashbars
Anyhow, I've probably scared you off but that's my 2 cents FWIW.......I will say that other than the Gen1 doohickey replacement, ALL these mods are optional and the desireablity of them will depend on you and what you do. If I had to limit my pics to three; it would probably be a skidplate, bars and footpegs......after that suspension, tires and handguards....and then.....