R45 Re-Commission

[nicholsonj2252]

Just bought this and I'm looking to do a mechanical re-commission on it





First item is the front brake master cylinder , its the 16mm round reservoir type

The brake piston and seals seems OK it looks to be either leaking from the lid - most likely as both the rubber diaphragm and the plastic washer are missing
or its coming from between the aluminium base casting and the plastic reservoir

I can get the rubber diaphragm from Motorworks but cant find anywhere that sells the washer - can anyone advise ? Its part 14 in the diagram below

BMW part number is :

32 72 1 238 388​

WASHER​

If it turns out not to be that and it's from bewteen the resevoir and casting how do I split them as I assume it's just an O ring that seals it ?

If none of these fixes work I can get a complete RH handle assembly with twist grip and the newer style square reservoir but I'm trying to keep
as many original parts as possible and in turn spend the minimum amount of cash ;-)

Any help much appreciated

 

[dicktheleg]

Can you measure it John and I’ll see what I have in my goodie store?

 

[JohnnyBoxer]

Nice bike and I saw it a couple of weeks ago & quite fancied it
Will watch with interest

 

[nicholsonj2252]

Can you measure it John and I’ll see what I have in my goodie store?

47mm

 

[The Other PaulG]

Nice bike and I saw it a couple of weeks ago & quite fancied it
Will watch with interest

Me too, I wondered where it had gone! It's in better hands than mine, thats for sure.

 

[The Other PaulG]

Will the next wanted ad be for a pair of R65 jugs and pistons??

 

[JohnnyBoxer]

Me too, I wondered where it had gone! It's in better hands than mine, thats for sure.

I thought the same

 

[AustinW]

I had an R45 back in 1980-84. Rather underpowered and definitely better as an R65. It used to make a strange farty noise from the crank case breather. Devilishly hard to get the carbs balanced too. I think it was on this one that the carb diaphragm kept tearing too. BKW 311T. Red. Part ex’d for a fiat 128 eventually. Happy memories. Thanks.

On the brakes I had an ongoing problem with a leaky m/c. IRC it was the seals on the piston - parts 11 or 12 I should say or possibly 17/18. But it was along time ago.

 

[steve hughes]

Having read and viewed John’s previous rebuilds and refresh’s on here Im in

 

[Deise]

Having read and viewed John’s previous rebuilds and refresh’s on here Im in

me too

 

[nicholsonj2252]

I had an R45 back in 1980-84. Rather underpowered and definitely better as an R65. It used to make a strange farty noise from the crank case breather. Devilishly hard to get the carbs balanced too. I think it was on this one that the carb diaphragm kept tearing too. BKW 311T. Red. Part ex’d for a fiat 128 eventually. Happy memories. Thanks.

On the brakes I had an ongoing problem with a leaky m/c. IRC it was the seals on the piston - parts 11 or 12 I should say or possibly 17/18. But it was along time ago.

I've checked 11 and 12 and all is fine , 17 & 18 are the screws for fixing it to part 10

It's leaking at either the lid or around the body of the reservoir

 

[sye]

An image search suggests that it's an odd looking sealing washer that looks like this?

 

[The Other PaulG]

Should I start a new thread, ' Dibs to buy the R45 once it's been Nicholsoned'?

 

[nicholsonj2252]

An image search suggests that it's an odd looking sealing washer that looks like this?

Indeed - but can't find anywhere that actually sells them . I need a friendly 3D printer guru I think

 

[King Rat]

Looking forward to the story of the winterisation!

 

[Steve398]

That’s very nice isn’t it! I had one when I used to do CBT’s, a great bike for that sort of thing but I preferred my 650 tbh.

 

[nicholsonj2252]

Horn on the R45 is non functional , I think I will have to send BMW an email complaint as 46 years service is just not good enough LOL

Anyone got one as ideally I woudl like a used period correct replacement

 

[nicholsonj2252]

Started the stripping and cleaning and everything so far other than the horn is in good working order . All of the electrics are working , it's got good spark , compression on both pots is150 PSI and thats before I've checked/adjusted the valve clearances . Carb rebuild kit , new fuel lines , in line filter and new throttle cables just been delivered so that will keep me busy for a couple of hours

 

[Mad Hatter]

Looks to be in very good condition

 

[nicholsonj2252]

Looks to be in very good condition

For being 46 years old it is