Recently, when I tried to kick-start my good old R27 - bangelydang - the kick start lever broke cleanly in two pieces.
Now two questions:
1. did that happen to anyone else?
2. could something more vital do the same? E.g. something within the gear or engine, which might block a wheel at full speed.
R27 - kick start lever broken
-
Gerry Douglas-Sherwood
Re: R27 - kick start lever broken
Hi Rolf,
Looks like it wasn't your lucky day. However, don't despair. Those kick-start levers are normally robust enough to stand a great deal of abuse, and are generally readily available.
That goes for the gearbox too. Not much chance of bits breaking off internally you'll be pleased to hear, just change the monograde 40 oil once a year (that goes for the bevel gear too), fit a new lever and enjoy your riding.
One thing however that is worth checking from time to time is wear in the driveshaft/ pinion splined coupling. If not kept lubricated the male/ female splines can wear dramatically, and replacement parts are rare and expensive. Simply rotate the drive shaft with you fingers to and fro. Ideally there should be no detectable play between the pinion and the shaft. If there is, special tools are required to dismantle the assembly for checking and lubrication.
DON'T be tempted to squirt oil into the coupling as there are rubber rings in the assembly that can perish. Dismantle and use proper spline grease. BMW in their misguided wisdom made no facility to maintain that coupling at normal service periods.
I have seen those coupling teeth worn to the size of needles in high mileage R26 and R27 machines, so watch out!
Have a nice day,
Gerry
Gerry
Looks like it wasn't your lucky day. However, don't despair. Those kick-start levers are normally robust enough to stand a great deal of abuse, and are generally readily available.
That goes for the gearbox too. Not much chance of bits breaking off internally you'll be pleased to hear, just change the monograde 40 oil once a year (that goes for the bevel gear too), fit a new lever and enjoy your riding.
One thing however that is worth checking from time to time is wear in the driveshaft/ pinion splined coupling. If not kept lubricated the male/ female splines can wear dramatically, and replacement parts are rare and expensive. Simply rotate the drive shaft with you fingers to and fro. Ideally there should be no detectable play between the pinion and the shaft. If there is, special tools are required to dismantle the assembly for checking and lubrication.
DON'T be tempted to squirt oil into the coupling as there are rubber rings in the assembly that can perish. Dismantle and use proper spline grease. BMW in their misguided wisdom made no facility to maintain that coupling at normal service periods.
I have seen those coupling teeth worn to the size of needles in high mileage R26 and R27 machines, so watch out!
Have a nice day,
Gerry
Gerry
-
Rolf_B
Re: R27 - kick start lever broken
Hi Gerry,
Thanks for the answer. In terms of lucky day: the day before, my key broke in two as well, this is why I started worrying a bit.
Anyway - my English is a bit poor for the rest of your mail. Are you referring to the connection between drive shaft and the rear wheel drive, which is connected via that rubber disk (actually polyurethane - we call it Hardy disk)?
I had to exchange that some time ago, because it was reduced to some crumbs of rubble.
Thanks for the answer. In terms of lucky day: the day before, my key broke in two as well, this is why I started worrying a bit.
Anyway - my English is a bit poor for the rest of your mail. Are you referring to the connection between drive shaft and the rear wheel drive, which is connected via that rubber disk (actually polyurethane - we call it Hardy disk)?
I had to exchange that some time ago, because it was reduced to some crumbs of rubble.
-
Allan Atherton
Re: R27 - kick start lever broken
>
Please explain this in more detail. Where is this splined coupling in relation to the Hardy disk?
>
Are these the two rubber spacer O-rings that fit on the drive pegs on each side of the Hardy disk?
Please explain this in more detail. Where is this splined coupling in relation to the Hardy disk?
>
Are these the two rubber spacer O-rings that fit on the drive pegs on each side of the Hardy disk?
-
Geoff Curtis
Re: Gerry Douglas-Sherwood.
I,m interested to know who this knowledgable man is and his background to this knowledge, as have not read this site for some time. Keep up the great answers Gerry. Regards Geoff in OZ.
-
Gerry Douglas-Sherwood
Re: R27 - kick start lever broken
Okay everyone, where the bevel gear pinion sticks out of the final drive housing a small diameter, male splined coupling is attached by a castelated nut (similar to the tiresome nut that hold the output flange on the gearbox).
Behind this male coupling is a collar.
The driveshaft has, on the opposite end to the gearbox, an internally toothed cup that fits over and engages the pinion male splines (as above).
This splined cup CANNOT BE REMOVED from the shaft. If the spline teeth are kaput, the whole shaft ist kaput too!
This splined coupling is held together by the locking collar.
To dampen out any horizontal shocks a rubber ring is fitted either side of the male splined coupling. The part number is: 33 12 3038163 (1972 BMW Parts Book). It is these rings that might deteriorate if oil is injected into the coupling.
Because of the limited travel of the rear suspension of a R26/ 27, this non-oilbath coupling allows for deflection between the shaft and final drive unit, just as the male/ female splined coupling does on the twins.
Credentials? I was trained as an engineer with Volkswagen Motors in th UK. I have been working on BMW motor cycles for 27 years, mainly on pre-'69 bikes because I love them. My oldest restorations were R24, R5, R12 and R66, R51 and R71 models. My last restoration was to create one 1959 R26 from two basket cases, hence the intimate knowledge of the driveshaft problem. I run a 1958 R50 I've had for 27 years; present mileage is 225,000 +.
I hope this clarifies things.
Cheers guys,
Gerry
Behind this male coupling is a collar.
The driveshaft has, on the opposite end to the gearbox, an internally toothed cup that fits over and engages the pinion male splines (as above).
This splined cup CANNOT BE REMOVED from the shaft. If the spline teeth are kaput, the whole shaft ist kaput too!
This splined coupling is held together by the locking collar.
To dampen out any horizontal shocks a rubber ring is fitted either side of the male splined coupling. The part number is: 33 12 3038163 (1972 BMW Parts Book). It is these rings that might deteriorate if oil is injected into the coupling.
Because of the limited travel of the rear suspension of a R26/ 27, this non-oilbath coupling allows for deflection between the shaft and final drive unit, just as the male/ female splined coupling does on the twins.
Credentials? I was trained as an engineer with Volkswagen Motors in th UK. I have been working on BMW motor cycles for 27 years, mainly on pre-'69 bikes because I love them. My oldest restorations were R24, R5, R12 and R66, R51 and R71 models. My last restoration was to create one 1959 R26 from two basket cases, hence the intimate knowledge of the driveshaft problem. I run a 1958 R50 I've had for 27 years; present mileage is 225,000 +.
I hope this clarifies things.
Cheers guys,
Gerry