R65 gearboxes - compatibility

[Adamastor]

Hi!

I was wondering, across all R65 production were there significant differences on the gearboxes? I have seen some with kick starter, mine doesnt have one (and it's doomed with the circlip-less serial number).
Are all 248 engine gearboxes compatible between each other (plug and play) or were there any significant differences among production dates?

Many thanks...

Sergio

[nhmaf]

The gearboxes from the 78-79 bikes have a slightly longer input shaft splined section, as they are used with the "old style" heavy flywheel&clutch design.  In 1980, BMW switched to the lighter "clutch carrier" assembly on all airheads and the transmission input shafts on these bikes is slightly shorter to account for the slightly greater width (length?) of the clutch carrier assembly.   Along with this, they also changed the pushrod&throwout bearing/piston assembly that is at the back of the transmission.   I think that they made some modification to the shift plate/cams inside the transmission as well.   In the USA, the kick-start option was not offered on any bikes after 1980, I believe, and it was not easy to get on any bikes after 1976 here.
The transmission from any 1981-1984 airhead (R80, R100, R45, R65) will work/bolt on any other 81-84 airhead.   The internal gear ratios are all the same, etc -only difference is the final drive ratio.  The pre 1980 bikes have some compatibility as well, as far as I know, a 78-80 R80/7 or R100/7 transmission will fit on an R65.

I thought that the circlip-less transmissions didn't start until 1985?

[R65Singh]

In the USA, the kick-start option was not offered on any bikes after 1980, I believe, and it was not easy to get on any bikes after 1976 here.

Hmmm...that makes me wonder if my transmission was ever replaced by PO.  Since it has a Kick starter and it is a 1982 R65LS.  How can I tell if it is  original or replaced tranny?  Always there is something interesting about these older bikes.  

[Adamastor]

 In 1980, BMW switched to the lighter "clutch carrier" assembly on all airheads and the transmission input shafts on these bikes is slightly shorter to account for the slightly greater width (length?) of the clutch carrier assembly.  
I thought that the circlip-less transmissions didn't start until 1985?

My R65 is a 1985 R65t (police force series) so it is doomed with the circlip-less serial number.
I dont have an easy way to know if it has been fixed by previous-owners, but I keep on looking at R65 gearboxes on ebay... it would be good to have a spare just in case.
Now I know that it must be a gearbox from a 1980 or later R65...

Many thanks for the info!

Regards...

Sergio

[Bob_Roller]

The 1980 reference, is a manufacture date, not a model year  .

The second generation R65 started production in 09/80, as an '81 model year bike .

[Ed Miller]

R65Singh, I think the Canadian BMWs had, or at least could have, kick starters.  My friend has a '91 or so R100GSPD and it is from Canada and has one.  If I was shopping for a backup tranny I would prefer one with a kick starter, even though I've read you can wreck stuff if you use them very often.  

[Patrick_Krivacka]

I'm also interested in this subject. I really prefer a kicker on a motorbike. My bike was made in 04/80. Does that make it a first or second gen. r65?

[Bob_Roller]

That makes it a 'first' generation R65, the 'second' generation started production in 09/80 .

[Patrick_Krivacka]

I just read someone say the '79 ('80 the same?) r65 was the lemon of the r65's. true?

[Bob_Roller]

I've seen that in print as well, don't have any first hand experience, the members here that have the '78-'80 year bikes seem to like them as much as the later bikes .

They were meant as entry level bikes, so they may not have the features of the larger bikes .

[nhmaf]

Actually, many people like to preach that the 1980 model year for any BMW is a bad year.   Admittedly, it was an akward "crossover" year for BMW as they switched to different clutch assemblies, air boxes/snorkels, valves, etc, etc. and many other changes that happened quickly through 1980-1981 on all their bikes, including the R80 and R100 lines.  A number of features which were first tested on the 78-80 R65 bikes were carried onto the R80/R100 bikes for the 1981 model year (an example would be the cush drive mechanism in the shaft drive assembly).    BMW follows/followed the production schedule in that any model year bike line started production in September of the previous calendar year, when everyone returned from their month-long August vacations.   It seems that at least some BMW bikes that were built in early September may have had some  "leftover" parts used from the remains of bins from the Spring/summer production run.   This may or may not be true, but some folks find bikes with a mixture of parts (which could have been installed by previous owners) which sometimes reinforces this theory.   The bikes themselves aren't bad and the quality control has always been the same - it is just that there may be some "hybrids" of that year out in the world, which can make parts replacement more challenging - especially to the "new" airhead owner.

[msbuck]

Does that make it a first or second gen. r65?  

i-man - I think yours is a multi-generational bike.  

[Patrick_Krivacka]

tell me about it. i just found out that my carbs are r80 carbs. Not that that's a bad thing!

[nhmaf]

That's OK about the carbs i-man, the carbs themselves are the same, it is just the size of the main jet (+1 size up, I believe) and the position of the jet needle that was the difference between the R80 and R65, at least on the 81-84 model year bikes, according to my Bing manual anyhow.   I got a good deal on some R80 carbs on the 'net and snapped them up because of this.

[TheAlchemist]

Hi Guys,

I really wish one could adapt a Kick-start to the later models. Mine is a 86 model monoshock. If there are any way around it can someone please post on here.

My battery ran flat the other day when I left the ignition on. I have since recharged the battery and it is business as usual.