I owned an '84 XR500 a couple years ago. Pretty good bike, actually. The motor had a lot of torque. The bike actually felt smaller than my 600 (thinner through the mid section), although it was kinda heavy. It had dual carbs, but I never had any trouble with them, it ran great.
Right after I got rid of it, it had catastrophic valve train failure.....but I think that was from years of sand dune riding with a 300+lb guy aboard (not me). :scream:
Speedstyle, For the most part these machines are pretty solid and reliable. In stock form, I have never heard of any "weak spots". Considering it's age, I would go through the head and replace valve springs/seals before flogging. The only tranny failures I have seen are on "highly" modded desert and flat track motors. A common fork set-up was 20/30 progressive springs, 70mm preload spacers (pcv pipe), and 7.5 wt oil at 130-150mm. A 600/700 pound rear spring would also help. Many guy's swapped early model CR forks on these. XR's Only has a pretty large inventory of old new stuff for these. They would surely love to deal on some of it, I'm sure.
I had an '82 XR5, loved that bike! I sold it too my riding buddy and she's still chugging along. It'll flat out haul in the open and as stated above tons of tourque. Be careful that bike will come up on you fast. I'm not sure if the 84 has the disk front brake as the 82 still had drums, I had trouble with those and the air filter was a bear to get replacements for.
Hard parts are obtainalble but plastics and such are non-existant :think
I had an '83 XR500, and I only have one word--PIG!
Actually it was a good bike, but I like my XR400 lots better. Like Rod says, plastics are unobtanium any more (except for maybe Maier--you might check them out), and tickling two carbs can be a pain in the patootie.
Otherwise, a decent mount, loads of torque, suspension (well, Ochster probably has the right idea).
I really only had one failure on mine--busted shift fork. I only had neutral and first gear. My brother's '84 busted the auto-decompression actuator (down by the kickstarter) and that made the compression release stay open. If we'd have just unhooked it from the kickstart actuator, he'd have been all right. Instead, we went through a major teardown! After having all sorts of engine work done, I found the missing piece. Sunk a lot of money into that pig!
Warning! Some OEM parts are no longer available for the RFVC XR500 (83 & later models).
If the bike's been treated nicely, and ridden normally, they're pretty much bullet proof. Unfortunately, if someone has starved the thing of oil, or not changed the oil frequently enough, bad things have happened.
As on most RFVC Hondas, the only real weak spots are the center cam journal and the small end of the rod. In low oil/bad oil conditions, the center cam journal wears and drops metal down into the lower end. Also, the small end of the rod galls, and then stretches.
Both of these problems will cause engine noises. Anyone familiar with the normal sounds of an RFVC Honda can tell you if the bike you're looking at sounds okay or not. If it sounds good, then it's probably a good bike.
If there's funny sounds, don't buy it, even if it's cheap. Fixing a worn center cam journal is do-able, but you have to start with a new cam and cover -- not cheap.
If the rod is bad, there's no replacements available. Not from Honda, not from Niks, not from Hot Rods.
A friend of mine over here bought an '83 xr500 for $300AU (approx $150USD) awhile back, and it was in shocking condition. We've chased up a 94 model frame, swingarm, brakes etc, 91 model cartridge fork front end, I have plastics to suit it and an acerbis tank. We have to convert it to a single carb setup, looks like an late model head will be in order. After this once we find a suitable '91 onwards shock and rear wheel / hub for it we'll be set. Bit of a franken-XR really. Makes you wonder if it's worth it in our case but the challenge is half the incentive. Anyway we're left with a pile of '83 parts which are the same as the '84 if you need any let me know. Long way away but our dollar is pretty low at the moment so it may be worthwhile.
The same guy earlier had a pristine condition '83 XR5 and we swapped bikes for half an hour or so one day. It felt heavier than my '96 XR6 (and it is) but It wound on nicely and wasn't to bad too ride, the suspension felt very mushy though.