I recently figured out I don't have enough time to go offroad riding anymore and that my DRZ sucked for the highway - so I sold it. One of the candidates for a replacement is a 1987 BMW R80 that's owned by a local mechanic friend. Unfortunately I don't know much about airheads as I've only ever owned a Funduro, and I could use some advice when it comes to inspecting it. I won't get a chance to ride it until late next week. It has pretty low mileage (for an airhead at least), at about 19K miles. The original owner was an older guy, and he seems to have taken good care of it. The inside of the tank is spotless and will be coated before I buy it. Steering was tight and there wasn't any clunking. Tires are decent and have plenty of life left. Supposedly everything works as it should. The final drive seems to have very little play in it and doesn't make any ugly noises when turned by hand. It comes with all major service done. Aesthetically it's just so-so - no dents in the tank, but there's a scrape on the bottom edge (no metal damage). There are some minor scratches and stuff, but nothing bad. Looks like it's been dropped once or twice, but never really laid down. No bags or frames. So, inmates, what else should I be checking? He's asking $3,000 (firm) - does this seem a bit high? Should I be paranoid about the circlip fix not having been done?
Okay here goes. The 87 R80 is one of the best of the breed. BMW pretty much was at it's pinnacle at that point. The R80 engine all by itself is one of the smoothest running boxers ever made. A few clarifying questions first: Where or what is NOLA? sometimes there's someone right around the corner that can help with the bike, so being more specific can be to your advantage, If the inside of the tank is so clean, why is going to be coated? That just doesn't add up. Needing to coat the inside of the tank usually indicates that the liner is shot and/or there's a rust or corrosion issue. Final drive play at 19K miles? That ain't right. Where are you getting play? The mono lever rear has no output splines to wear, so I can only assume that you're grabbing the wheel alternately ( 12&6 o:clock, 3&9 etc) and check for play there. If you have play there, that usually indicates high mileage or a premature output bearing failure. Not a "cheap" undertaking. The parts alone are around $100.00 if that's all that is wrong. As far as the circlip is concerned, the lack of one does not guarantee that the trans will fail. If I was to open up that trans for any reason, I would do the mod, but if it isn't causing problems, just keep and open ear for changes in the sounds. BUT, I think that 3K is a little high if the tank need lining and the final drive has play issues. Just my $.02 worth
I nice post 85 R80 has been worth $3500 since they were new and they are still worth it today. I have bought and sold many and never lost any money. So $3000.00 gives you room to find some used bags and mounts:)
Thanks, this is great advice and just what I'm looking for. NOLA is New Orleans. The only airhead owners I know down here (not counting the seller) love their bikes, but don't know a whole lot about the mechanical details of them. What I meant when I posted about the final drive was there is almost no play whatsoever in it. I'm testing it by grabbing the rear wheel and rotating it by hand. I should have worded my original post better. I'm not actually sure why he's lining the tank - it didn't look like it was needed, so I assumed it was a preventative measure. I'll try to borrow a borescope and have a closer look at the corners where I couldn't see with a cellphone flashlight. As for the circlip... are there any distinctive sounds it might make, or any symptoms?
The circlip problem does not usually have any warning of failure. One day it's fine and the next you have a blown rear transmission cover. It is certainly not something that should prevent you buying the bike. Many maintain they will last forever others worry about it. I believe it should be fixed when time and money permit. I would be able to do this myself so it might be cheaper for me than someone who has to send the whole job or part of the job our. We should probably talk more about the circlip after you buy the bike. Sounds like the tank lining in this instance is preventive maintenance. It usually is applied for this reason. Can also be part of a curative when there has been a problem. There are several tank linings used these days. The favorite seems to be POR 15. But there are others and there is at least one that has been the cause of problems later. Find out which tank lining, method, he is employing. Buy this bike ASAP.
If what you just described as the play that you're feeling, that's great! That's just the normal backlash between the pinion gear and the ring gear. Sounds excellent! As far as the lining of the tank is concerned, it came from the factory with a red liner. It sounds as if that may be going away and he is coating it. I recommend POR 15 as Disston mentioned. Do NOT use Kreem brand, it has a history of coming undone after awhile and then it's and unholy nightmare to get it out. BUY THE BIKE. Even if the tank is shot you can budget 2-4 hundred for a replacement. Thanks for the Clarifications.
+1 (FD play), +1 (POR 15, not Kreem), +1 (Buy it), +1 (200 for an average tank, $4-500 for a mint one), +1 (because I like BMWs)
Be sure and check the wheels for dings. The bend all too easy. I wouldn't touch the tank unless it needs it. +1 on the Kreem. The circlip issue most always gives warning just just like a tranny with a circlip when the front output shaft bearing goes bad. Front output shaft bearings go bad all the time circlip or not. Learn where that bearing is and listen and feel for trouble. Disston, rear blown covers are about as rare in my experience without a circlip as they are with one. If the bearings are left on to get that bad, that rear cover will get torn up regardless of whether or not it has a circlip for the shaft walloring and/or breaking.
I wouldn't waste the money. With the gas tank - if the inline filters stay clean I wouldn't worry about it. If you are going to seal it my painter only uses POR15 and he says it's the best stuff ever. I've used Kreem in the past mostly on old Heinrich tanks and I have not had very good luck with it.
IMO they finally got the CR about right in the later models for single plugs. The only reason I would dual plug is if I am raising CR. I just raised my own CR to around 10:1. There is no way I would do that without dual plugging. If I was hot rodding a R80, the first thing I would do to it would be go to the biggest bores I would run which are 94mm 1000cc bores but that's just me. That in itself will get you a very noticeable power increase. Big enough that you would most likely be looking for taller gearing to better take advantage of all the extra power.
Thanks everyone for the advice - I'll be headed in to put a deposit down on it this week it seems. One more question: I don't like cast wheels, but I know spokes weren't an option for this type of suspension. I did find the thread on here discussing having a spoke hub machined for use on this type of bike, but it looks like the rim was likely to crack as it had to be laced off-center. Can I replace the entire final drive unit with one off of a GS and use the GS rear wheel, or will this not fit?
It is doable however it is a lot of work. I am doing the opposite and going with alloy wheels and a rear disc on a build and there is a lot of time and fabrication involved.
