R65GS, help please

[nick.ct]

I have been looking for a while for some exhaust downpipes for a R65GS. They seem to be rarer than the bikes themselves.

Has anyone had to replace them before? Where can I find some? Does anyone know of a source of these or a substitute?

The bike is nearly ready but I need to sort something out for the exhaust downpipes, the collector box and silencer are standard R80ST.

Advice, wisdom, useful pointers all gratefully received

Thank you

Nick

 

[MiGSel]

I've got the original ones off my R80G/S.

They are pitted but usable.
I can get them coated in heat risistant black too if you want.

Interested?

Cheers,
Michel

 

[Bill-H]

I've just bought a new muffler for my R65GS from BMW, all the exhaust parts are still available from BMW, so if you are stuck, you could always buy genuine new ones.......

 

[jez]

The down pipes on a r65gs are smaller in diameter than the r80g/s especially the restricted 27hp version, not sure about the 50hp version. you will need the frame number so the dealer can get you the right ones as there is a difference. look on http://www.realoem.com/bmw/ for the part numbers.

cheers
Jez (ex r65gs owner)

ps my old (restricted) bike has just completed the Heroes and Legends Dakar Rallye, came in 42nd ish out of 67.

 

[nick.ct]

Thanks for the replies

There is a difference in the downpipes between the R65GS and the R80ST, both in the diameter where they go into the heads and also because the 650 engine has a shorter stroke and about 2-3 inches narrower, they have different bends in them to bring them parallel to the frame tubes before connecting to the collector box.

I was trying to see if anyone knew of any aftermarket down pipes, but if no one here knows of any, it looks like I'll end up with original BMW ones.



Nick

 

[(RIP) Proff]

Got me thinking

Nick.
Could you please post a pic of your barrels.
or count how many fins on the Barrels. [not including heads]
There is a good reason, I promise you

 

[Bill-H]

Hey Proff
Not wanting to feel left out, I have 17 fins on my R65GS - just been and counted them...
Bill






fins 'ain't wot they used to be......

 

[nick.ct]

Here's a picture of the engine, its a '87 year one, civilian

 

[(RIP) Proff]

Paging Mr Steptoe, Mr Steptoe to the airhead forum please.



Neil, is that what I think it is ???

 

[nick.ct]

Hey Proff

What's going on?

I cant stand the suspense

Tell me, tell me

 

[(RIP) Proff]

I need Neil to confirm it, just recount the fins up to the head joint. and whats the number of fins on your 1000 cc airhead barrels up to same point...

 

[nick.ct]

Well....... as far as I can see and taking the head gasket as the join

On the R65GS, there's 8 fins on the barrel and 9 on the head

On the R100GSPD, there's 10 fins on the barrel and 9 on the head

Should there be some other number?

Nick

 

[Steptoe]

Paging Mr Steptoe, Mr Steptoe to the airhead forum please.



Neil, is that what I think it is ???

Just looked at the pictures and .............................. it's not what you think it is. It's standard.

 

[Rob Farmer]

The bore size will be stamped on the top side of the barrel - between the bottom fins and the crankcase. there'll be a 1 if it's a 1000 or an 80 for an 800. Don't know what the 650 has though - presumably 65.

 

[nick.ct]

Neil, thanks for casting your expert eye on the picture.

I'm still not sure what all the questions were about, did Proff think that the barrels were not standard R65 ones? I'm pretty sure its a standard R65GS, it seems like the other R65 engines I have seen. Did BMW make some specials or something, I would be interested to know? Certainly the frame number shows up as a '87 R65GS on the Realoem website.

Still leaves me with the problem of finding some downpipes, I think that they are unique to this model and that at over £110 each from BMW I might try to have some standard R65 pipes modified to fit the a R80ST collector box. Instead of pointing out to fit standard R65 silencers, they need to point inwards to connect to a collector box. Does anyone have any ideas about this?

Thanks again for all the advice, comments etc

Nick

 

[Bill-H]

Nick, yours looks exactly like mine ( apart from the length of red wire).
Mine has '65' in the casting where the barrels meet the main block, and '06 A 71' stamped into the casting on the corner opposite. Don't know what these other numbers mean, bore diameter? weight of barrel?
There was also a 50hp version of these bikes made, but expect the exhausts were the same bore as the 27hp ones.

Would the downpipes off any of the other R65's fit? as they seem to be listed with the same bore and stroke as the R65GS........

 

[nick.ct]

Bill, hi

The red wire is just the optimate! The standard R65 downpipes will fit at the head end but do not connect with the collector box. Looking at the prices of OEM BMW parts I think I will look at modifying some R65 downpipes that I have so that they will connect to the collector box, maybe by using some flexi stainless exhaust coupling. I suppose it is no surprise that with so few bikes of this type made that there is no aftermarket parts available.

Nick