General Maintenance



Air Filter There are various aftermarket air filters available, I've always used the standard one.

These are quite expensive. I’ve not replaced them regularly or frequently, more like 20,000 km/two years/when they’re dirty.

Alternator Rotor These seem to fail somewhere between 70,000 and 200,000 km. I've replaced them where necessary with rewound exchange rotors that I was told were better than stock because the wiring was bound down (stock rotors have the coils visible). The impending failure can be predicted by checking the resistance across the slip rings, which can be done without removing the rotor from the bike.

Removing the rotor requires that a "BMW special tool" be put down the threaded hole in the front of the crankshaft. As recommended by the Hayes manual, a rod approximately 6mm diameter and 40-50mm length. Mine is a 45mm piece of 5.5mm Allen key, it works fine. 

The battery light always glows faintly, and can be particularly disconcerting if one is suddenly on the bike at night out of town. Checking resistance in the stator and rotor is a good way to reassure oneself that failure is not imminent.

Battery  In the 1980s I tried aftermarket batteries but didn’t find one that was up to the job of cranking over the 650, so stuck with BMW originals. This problem seems to have been fixed, there are a variety of aftermarket batteries that do the job. Currently I use a Motorbatt battery,

I've found that the BMW battery goes fine until it dies, and does so suddenly. I once had it start the bike fine until one morning it was almost impossible to start. The next day, riding it home (500km away) it was so bad that the engine cut out under 3,500 rpm with the headlight on. I was able to get back home by putting Epsom salts into each of the cells, which helped considerably. (This was 1990, the current battery is sealed and won’t accept this.)

The battery bracket tends to rust out after a while. This can be postponed by painting, and I've found that it is helped to put in a rubber mat (of old inner tube) under the battery to cut down on vibration removing the paint on the holder.

Bean Can The Hall Effect sensor (Ignition sender unit) mounted on the front of the camshaft can be rebuilt but when I tried this I wasn't confident that the result would be reliable and replaced it with a Wedgetail unit. I'd recommend these going forward. 

Bearings I'm told that the only bearing that is a BMW special is on the gearbox input shaft. All the others can be purchased through standard bearing shops. Certainly I've found this in practise.

I once had the big end on the RHS cylinder fail. This is apparently rare because it is the LHS big end that is further from the oil pump. The symptom was a "clacking" sound at particular vibrations (but not all). I replaced it myself and, despite it scoring the crankshaft, the bike was quite reliable afterwards.

Brake, Front. The callipers on my bike are Brembos. I have no experience with the ATE brakes that came out with some LS bikes. The front brake is excellent. The front has always been noisy, probably because the pads are loose inside the callipers. I've come across various solutions to this, including coating the backs of the brake pads with goo (designed for the purpose) or with duct tape, but I've settled on leaving them to squeak. It isn't pleasant but at least people hear me coming.

At one point I found that the brake light switch wouldn't disengage, and left the light on continually. I replaced the switch but this didn't fix the problem. I then replaced the brake lever. This had worn on the contact point with the piston to about 1mm depth, and there was a bit of wear to the alloy around the (steel) post that it pivots on. The combination of these had caused sufficient slackness to make the light switch ineffective. Surprisingly, I found that braking efficiency was drastically improved with the new lever: it was able to apply pressure to the piston much more efficiently.

The front rotors were replaced at about 145,000km. They were overdue at this point. On reassembly I found that the dust covers on the pistons were degraded and falling apart. I rebuilt both callipers, a fairly expensive exercise because the kit is specific to this model bike (other R2V bikes use a kit that is available cheaply). Replacement was straightforward but these two youtube videos helped:


I once replaced the master cylinder because of a bit of "notchiness", but it came back at another time and was fixed by putting some grease on post behind the lever. I think that the notchiness was caused by it getting wet after prolonged riding in the rain.

The original brake lines were replaced in 2019. This was overdue: there were a number of bumps in the rubber indicating impending failure, and once they were off the bike they allowed fluid to seep through when flexed. The replacement with stainless steel braided lines by Venhill from Motobins is working well.

Brake, Rear. The rear brake is poor and useful mainly for low speed manoeuvers.

The switch for this routinely fails, I assume by filling with crud.

Note that the shoes are specific to this model bike because of the unusual mag wheels.

Clutch I was told once that the clutch was the same size as a VW clutch, but have never had one fail and so have never tried to confirm this.

Coil I once had one of these break down, and it caused great difficulty starting the bike. The bike ran well once started, though. The specs for resistance across the terminals of the dual coil were a good indication of the problem. The replacement was expensive. I'm told that the Kawasaki GPZ900R used a pair of identical coils, and could be fitted after some modification of the mounting brackets.

More recently I’ve installed a 1.5 ohm Dynacoil. These are substantially cheaper and seem to work fine.

Incidentally, the spark plugs fire simultaneously, one into the compressed charge and one into the exhausting gasses. The bike runs perfectly well with the leads swapped between the cylinders.

Control Cables Both the throttle and choke cables are split from one cable to two in a splitter block under the tank. These routinely rust out and fail: it's good preventative maintenance to dismantle and grease them occasionally.

I've never had a clutch cable fail, which I find pretty amazing. Most of my adjustment of the clutch mechanism seems to be to compensate for clutch wear rather than cable stretch.

The choke lever is positioned with a captive ball bearing. On one of my bikes it fell out and was lost: substitution with a 4.0mm (5/32”) bearing from a bicycle shop fixed this.

Engine Vibration These bikes have always had an annoying vibration at about 5,000 rpm (120km/h in 5th gear). There are various fixes for this that have been proposed, particularly replacement of the spacers on the engine mount rods with hard rubber from shoe repairers, but I've never tried them. Instead, I've kept the speed under 115km/h or above 120km/h, which has no doubt helped me avoid speeding fines.

Exhausts The original Black Chrome ones rust out, my first bike requiring the replacement of the original mufflers at about 60,000 km. These were replaced with Staintune stainless steel versions that had been left unpolished so that they would take black paint. My current bike has a full Staintune system (headers and mufflers) and is polished. It isn't original but looks good. I saw one once on a dealers floor with highly polished stainless headers that faded from golden at the exhaust flanges to the crossovers under then engine, and it looked very good.

Exhaust Flange Nuts These hold the exhaust headers in and hold the seal tight around them. Trying to loosen them without the correct tool seems invariably to butcher them, and make use of the tool impossible in the future. An alternative is to take them to a bike shop to have them loosened and to ride home with them hand tight. This caused no problems when I tried it.

Fuel I used the lead replacement fuel available in Australia as a substitute for leaded "Super", but got variable results with it and I was advised that the fuel itself varies quite a lot. I currently use 95 Octane. The bike runs okay on 91 Octane, but poorly on 98 Octane.

I've had for years a Ryco fuel filter behind the fuel tap and have occasionally noticed it to be necessary: I've had the inside surface of it coated with crud, presumably from bodgy fuel. I think of these filters as a necessity. When the main tank runs out and I switch to reserve it sometimes takes so long for the flow to re-establish that the bike stops, which is problematic.

The fuel lines don't last forever. I had a problem with blockage in the transfer port of my carburettors that recurred despite there being a fuel filter in place. I replaced the hose, which had looked degraded and which I think was the source of the crud. It was suggested that the lines be replaced every 5 years, which I think is appropriate. 

Fuel Cap Eventually the ratchet associated with the lock on these breaks down and the cap can't be removed. I found this on my first LS and fixed it by drilling down from the top part of the depth of the cap and inserting a nail. A neater fix is to drill up from the bottom and insert a self-taping screw, which defeats the lock mechanism, but must be done before the ratchet fails. The cap on one of my current LSs has a different key to the ignition, so presumably the original has been replaced. I haven't yet done any drilling in it. I never lock it. 

Gearbox The slow, clunky, 5 speed box is very reliable, and I've never had one fail. The 4th gear tends to whine, apparently due to its teeth being straight cut rather than helical, and has done so on a few of my bikes. Some of the boxes have had false neutrals, but this is rare.

Gear Shift The slack in the linkage is a good way to gauge the "true" age of the bike, getting quite slack on the second or third time around the clock.

Ground Clearance Old R100s could, in skilled hands, scrape their tappet covers in corners. I've only ever done this once on the LS, immediately before the front wheel let go and the bike slid over a precipice. The stroke of the R65 engine is shorter than the R100 (61.5 Vs 70.6mm), and the clearance is better as a result. I've heard people complain about the ground clearance of R series BMWs, as though the tappet covers got in the way of leaning in corners: I don't think this applies to the R65. 

Headlight In all my bikes I replaced the standard H4 55/65W headlight bulb with a 55/100W. It gives substantially better night time penetration. However, in 2019 I realised that there's no headlight relay on this bike, so all the current goes through the LHS handlebar switch, so I switched back to 55/65W.

Instrument Pod Cowling The tabs that hold the leading edge of the plastic cowl over the headlight break. All the LSs I've seen in recent years have had some modification, such as self-tappers and little brackets, to compensate for this mounting failing. My trick has been to re-create tabs using fibreglass. The cowlings are, unfortunately, no longer available. 

Manuals I have copies of the factory workshop manual and also the Hayes "BMW Twins 1970 to 1985". The latter not only has data on all the BMWs I have owned, it includes useful info on improvising for BMW special tools. 

Panniers I've had bikes with both Krauser and BMW pannier racks. The Krauser racks have the advantage of a flat rack behind the seat on roughly the same level, allowing large things like suitcases to be tied down securely as long as there is no pillion. The BMW version is frames for the panniers only, no rack.

The Krausers have the disadvantage that a few nuts have to be loosened on the rack, and the rack slid backwards and down, if the seat is to be raised. The seat doesn't raise cleanly even if this is done. This becomes logistically difficult if the 13mm spanner is in the toolkit under the seat. The standard BMW racks don't have this problem (but also don't have the flat rack).

The mild steel brackets that attach the frame to the bike are in the habit of cracking. I've on a number of situations found them cracked, and the panniers and rack wobbling excessively, on a tour. In the short term the solution to this has been to tie up the cracked bracket with fencing wire, a metre or two of which I keep stuffed in the main frame tube under the tank. I've always used a tie-down strap around the panniers, (i.e. a single strap around the LHS pannier, over the rear subframe under the seat, around the RHS pannier, over the seat, and tightened using the ratchet device that comes with the tie-down) and don't know if this has helped support the panniers or has caused the strain that has broken the brackets. I'm aware that quite a number of riders experienced with panniers put an extra strap around them in case the pannier clasp gives way.

The Krauser panniers that came with my first LS were too small to take a helmet, but those that came with my second were much larger and could fit a helmet with ease.

Rear Shocks I replaced mine with "Ikon" aftermarket shocks. These seem to work fine. The original shocks had lost spring tension to the point where any attempt to carry a pillion would cause the bike to bottom out. The Ikons are made to the Koni design in Australia (note that the name is "Koni" with the "I" transposed).

Rocker Arms The contact point with the valve stem eventually pits. This can be re-faced and ground, but I was advised to replace the whole rocker with wrecked versions, which I did (on the R80 that I rebuilt).

If there is any slack between the rocker and the cushion that it pushes against it will become noisy. I tried to fix this for a time by installing shims, but was advised that the trick is to hold the cushions together before tensioning the heads so that the clearance is enough for free movement but not enough for rattle. I've found this to be much more effective.

Seat Eventually these crack and need re-upholstering. My current bike broke one of the hinges, and in practical terms this required that I replace the seat. This may have been prevented by correct adjustment of the rubber-faced posts that the seat rests on when the bike is being ridden: I suspect that one of these had got loose and slackened off, and that my weight was being held directly on the seat hinges.

The LHS post sits on a rubber block cable tied to the sub frame. The block doesn’t appear on parts microfiches. It was missing on one of my bikes, causing the seat to rattle. I improvised it by putting a part of an old rubber hose (the “inlet manifold” that joins the carburettor to the cylinder) onto the frame, holding it in place with a hose clamp.

Spare Parts The parts for this age of bike are now counted some sort of antique by BMW, and come up under a category like "Classic" in the parts catalogue. If the person checking the catalogue doesn't know this they'll end up with a 1985 r65, which might look the same.

Spark Plug Leads The original leads "broke down" and their resistance increased, which I fixed by replacing the caps with NGK 5kohm caps. I once fitted car-type silicone supressed leads and, although they work, I've found that they "leak" a little in wet weather and I can feel the tingling if they touch my shins. I've also been told that such leads will eventually damage the electronic ignition. 

Stands The side stands tended to crack and break. I replaced the stand on my second LS with a wrecked one but it was never as "tight" as the original, and the bike leans over too far. I've settled to using just the centre stand, except in emergencies.

The centre stand I eventually wore through on the right hand side. The rubber cap disappeared, and the stand filled up with rain, allowing it to rust from both the inside and the outside. It eventually needed a fair bit of welding to return it to working condition.

Starter Motor I replaced the 1983 starter motor with an Arrowhead item April 2022. It turned out that the problem was with the relay, not the motor, so presumably the Bosch is working fine. The new motor spins the engine faster and makes it easier to start (see the blog post on this).

Steering Head Bearings I've found that correct tension and adequate packing of the bearings with grease has had a substantial effect on improving the handling of the bike.

Tyres The R65LS is extremely sensitive to tyres and to wear of them. I once had a situation where a worn (but not illegal) Pirelli front tyre caused a wobble on wet roads. It was a metric size, I think 100/90. For a long time I used Metzlers. I was once told that the imperial sized Metzler was made specifically for this bike, and have found that these were good. Some time ago the imperial size front was discontinued and the 90/90 was substituted.

More recently I’ve switched to Michelin Pilot Activ, 90/90 Front, 4.00 Rear. These grip better in the wet, are much more stable, and are less sensitive to changes in tyre pressure.
I've always run inner tubes inside the tyres, despite the rims being tubeless type, because I've thought that it would protect me a bit better against flats.

I'm running 34psi front and 32psi rear solo, up the rear to 34psi with pillion.  The 28/26psi recommended in the book I find too low.

Wheels I once had a poor tyre fitting warp, slightly, the front wheel, and the bike setup a wobble after 120km/h. This meant that it was fine until I got half way through an overtaking manoeuvre. This had to be trued by a specialist in order to restore the bike to sane operation. I had a slight problem with my current LS with some out of true in the rear wheel causing an odd vibration at about 65km/h, which was fixed by the same shop.

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