BMW Performance

[Winston001]

Having just got my BMW R80 RT going after 12 years in a shed, my thoughts naturally turn to increasing its performance. I've just taken it to the Brass Monkey, had a great time, and the bike ran like a dream. But with the large fairing it will only pull 150kph and has never exceeded that speed in the past.

It is an ex-MOT machine, 1985 model.

In reality I'll never want to cruise at any more than 120kph (or slower) but the bike feels as though it could use a little bit extra oomph.

I've searched the net but not found anything helpful. Anyone have any suggestions or know of a reputable mechanic who can advise me?

[HDTboy]

Artifical aspiration?

[Kickaha]

Most common was to get some 1000cc barrels,pistons,head etc as they're a bolt on fit

If you dont want to do that the usual mods,exhaust,airbox,carbs work as well on these as any other bike

[Sensei]

1000cc barrels & pistons . Friend has done this convertion to afew R80's now tranforms the bike power wise by heaps . Could give you his number to have a chat if you like .

[Milky]

Me old man may have some barrels sitting downstairs / have access to some... We have some 148 mainjet carbs (up from 135 standard on the R80s) and possibly some other bits and pieces that would help you out on this front.

On any other airhead things like drive splines/rotors/universals etc give me a PM and we are likely to be able to help you out..

[zadok]

Welcome to K.B, Winston001.
Nice old Beemer you've got there. :ride:

[thehollowmen]

Tell me how it goes.
A friend has just hauled his up and has it on blocks after 6 years. He's having a go to get it back in working order.

He might want to do a bit too

[Bonez]

The fairing is the really the major issue here I think too. The ol man has an R80 and he scoots around the country side quite briskly with his mate on an a Honda VFR sumit-forget which model they all look the same... Dad just has a bikini fairing on his BM.

[Sniper]

Im with the others Winston001 (Bonds boss??) Pop a 1000 barrel, head, pistons and a couple of other bits and bobs in and you'll do well.
Welcome to KB, enjoy our humour (Biff), Wit (White_trash), sensability (Hitcher, Jim2 and a couple others), stirring (Winja, mikey and anyone with a red dot) and the people who make no sense (Yours truely).

Oh yea, small tip. Dont talk about how fast you can go as it ruffles the smart ones up (Those with few demerits left or lots of fines) and also tends to make the restless ones (Those that havent been caught yet and the "wannabe" bad-boys) want to race you.

[geoffm]

Go to the nive folks at http://www.siebenrock.de and get their shiney paper catalogue. Lots of bits for airheads, including big bore kits, etc. Not a cheap exercise though.
Geoff

[Ixion]

The fairing is the really the major issue here I think too. The ol man has an R80 and he scoots around the country side quite briskly with his mate on an a Honda VFR sumit-forget which model they all look the same... Dad just has a bikini fairing on his BM.

The RT fairing knocks about 20km (about 12kph if you have the electric screen) off top speed compared to the S models. Worth it , but,when it's pissing down with rain and cold as charity, and you're tootling along warm and dry

[Wolf]

Welcome, Winston001. Great bike. All the best getting it how you want it.

[vifferman]

Hi there, Winston001! :spudwave:

Welcome to the Kiwi Biker gargre! :niceone:

[scumdog]

Welcome to this site of Bedlam and chaos Winston001, might see you at some of the southern rallies perhaps?

[F5 Dave]

A friend took some beemer to the Brass a couple of years ago with a bunch of us. It was supposed to be some sporty model. Man it was slow, he got ‘soles about it as he had a perfectly serviceable RF900 in the garage, but he’d just swapped something for it so thought he’d take it.

Just wouldn’t rev out. Turns out the carb diaphragms were perished so the slides weren’t lifting fully, hence it was a slug. Quite common apparently on older BMs. Not that we let him off the hook for it.

[James Deuce]

(snip) a Honda VFR sumit-forget which model they all look the same(snip)
Bah! All Japanese across the frame in-line fours from 1969 to 1983 look exactly the same too.

[Winston001]

Im with the others Winston001 (Bonds boss??) Pop a 1000 barrel, head, pistons and a couple of other bits and bobs in and you'll do well.
Welcome to KB, enjoy our humour (Biff), Wit (White_trash), sensability (Hitcher, Jim2 and a couple others), stirring (Winja, mikey and anyone with a red dot) and the people who make no sense (Yours truely).

Oh yea, small tip. Dont talk about how fast you can go as it ruffles the smart ones up (Those with few demerits left or lots of fines) and also tends to make the restless ones (Those that havent been caught yet and the "wannabe" bad-boys) want to race you.

Cheers guys and thanks for the warm welcome. And the tip Sniper. :oi-grr: Speed isn't really the issue, acceleration and passing ability are really what I'm thinking about.

In my tractor I have come close to losing my licence on demerit points so it is a touchy issue for me too. In fact I was suprised at how fast bikes were travelling going to the BM Rally.

[Winston001]

Tell me how it goes.
A friend has just hauled his up and has it on blocks after 6 years. He's having a go to get it back in working order.

He might want to do a bit too

OK. My bike sat in a garage, and later a farm shed for 12 years. Full fuel tank, no battery. Wasn't turned over at any point.

Pulled it out 8 weeks ago and found the fuel cap had rusted shut. Here is the story if you want to read about it: http://pressf1.pcworld.co.nz/showthread.php?t=56650&highlight=BMW

New fuel, new battery, a push down the street - and it fired!! :niceone: Unbelievable. Rode off down the street 2 minutes later.

Haven't changed the spark plugs yet but did get the carbs balanced. Inside the tank has some rust so I'll need to clean that up. All electrics worked after judicious spraying of CRC. Tank has surface rust warts and the paint has flaked off some of the frame. New front tyre.

Gotta hand it to the Germans - they make bullet-proof machines. :love:

[Winston001]

1000cc barrels & pistons . Friend has done this convertion to afew R80's now tranforms the bike power wise by heaps . Could give you his number to have a chat if you like .

I must say this seems the most likely move. Only thing is, what does that do to the con-rod? I'm planning on keeping the bike for my son in the looong term (10 yrs old).

[F5 Dave]

OK. My bike sat in a garage, and later a farm shed for 12 years. Full fuel tank, no battery. Wasn't turned over at any point.
. . .


Really. Check those Carb diaphragms.

[Wolf]

Gotta hand it to the Germans - they make bullet-proof machines. :love:
My old Zundapp - had been dropped and dented by a previous owner, hadn't run for about 5 years before I got it. Charged up a battery, plugged it in and let rip, engine turned over a couple of times and fired - bike hadn't been properly "laid-up" or even carefully stored.

Bullet-proof.

So was my (Austrian) Puch - hadn't run for 5 or more years, we gave it some gas, tickled the carb, jumped on the kick start - and the roar nearly caused a mate of mine to shit himself (exhaust not connected to muffler).

[Ixion]

OK. My bike sat in a garage, and later a farm shed for 12 years. Full fuel tank, no battery. Wasn't turned over at any point.

Pulled it out 8 weeks ago and found the fuel cap had rusted shut. Here is the story if you want to read about it: http://pressf1.pcworld.co.nz/showthread.php?t=56650&highlight=BMW

New fuel, new battery, a push down the street - and it fired!! :niceone: Unbelievable. Rode off down the street 2 minutes later.

Haven't changed the spark plugs yet but did get the carbs balanced. Inside the tank has some rust so I'll need to clean that up. All electrics worked after judicious spraying of CRC. Tank has surface rust warts and the paint has flaked off some of the frame. New front tyre.

Gotta hand it to the Germans - they make bullet-proof machines. :love:


And welcome to the wonderful world of Whales.

Have you tried changing gear yet ? The Germans have to make their machines bullet proof because they know that there will be a lot of people turn a 12 guage on what the manual laughably calls the "gearbox"

[Bonez]

Bah! All Japanese across the frame in-line fours from 1969 to 1983 look exactly the same too.
Shit you bit well :whistle:

[Kickaha]

I must say this seems the most likely move. Only thing is, what does that do to the con-rod? I'm planning on keeping the bike for my son in the looong term (10 yrs old).

Same bottom end in those R80's as the R100 so the con rods wont be a problem

[James Deuce]

Shit you bit well :whistle:

Shit I forgot to include a smiley so the "friendly needle" would be conveyed.

[Eurodave]

If you want to junk the police solo seat & large R80RT fairing I make fibreglass replica R100RS full fairings , R90S bikini fairings & screens , complete dual seats & tailpeices/toolboxes, rear mudguards, sidecovers & front guards for both the earlier twin shockers & [your] single shocker R series. If you're interested just flick me a PM, cheers Dave

[Winston001]

If you want to junk the police solo seat & large R80RT fairing I make fibreglass replica R100RS full fairings , R90S bikini fairings & screens , complete dual seats & tailpeices/toolboxes, rear mudguards, sidecovers & front guards for both the earlier twin shockers & [your] single shocker R series. If you're interested just flick me a PM, cheers Dave

Crikey, that's excellent. I'm inclined to keep the bike original but the idea of an RS fairing is tempting.

I rode a Bol D'Or back from the rally and was suprised at just how much wind pressure the RT fairing protects the rider from. The Honda has a small fairing and a ton of grunt, but was fairly exposed to the frigid air.

Put hippo hands on the R80 for the rally - best thing since sliced bread. :niceone:

[Ixion]

Crikey, that's excellent. I'm inclined to keep the bike original but the idea of an RS fairing is tempting.

I rode a Bol D'Or back from the rally and was suprised at just how much wind pressure the RT fairing protects the rider from. The Honda has a small fairing and a ton of grunt, but was fairly exposed to the frigid air.

Put hippo hands on the R80 for the rally - best thing since sliced bread. :niceone:

Even better is the protection from rain. Get the screen position right and you remain almost completely dry at speed (still get a bit wet when you slow down or stop)

[Bonez]

Same bottom end in those R80's as the R100 so the con rods wont be a problem From the all the articles I've read over the years the R80 seems to be the smoother and better balanced of the two though.

[Milky]

New fuel, new battery, a push down the street - and it fired!! :niceone: Unbelievable. Rode off down the street 2 minutes later.

Don't make a habit of bump starting the bike as the locknut on the end of the gearbox can come loose and do some serious damage to the surface of the taper on the end of the output shaft...

[Winston001]

Ta Milky, learn something every day. :done:

[Enn]

Having just got my BMW R80 RT going after 12 years in a shed, my thoughts naturally turn to increasing its performance. I've just taken it to the Brass Monkey, had a great time, and the bike ran like a dream. But with the large fairing it will only pull 150kph and has never exceeded that speed in the past.

It is an ex-MOT machine, 1985 model.

In reality I'll never want to cruise at any more than 120kph (or slower) but the bike feels as though it could use a little bit extra oomph.

I've searched the net but not found anything helpful. Anyone have any suggestions or know of a reputable mechanic who can advise me?
You can try delorto carburettors as they have a accelerator pump in the carb twist the wrist and a good squirt of petrol will help you on yer way, allso have lotsa adjustments for tuning,dont know what they would cost, a rs fairing will help too lots less wind for ya to act like a sail and mess wet inna rain, good luck .... :yes: :ride:

[Enn]

oops i mean less wet inna rain :whistle:

[Ixion]

.. a rs fairing will help too lots less wind for ya to act like a sail and mess wet inna rain, good luck .... :yes: :ride:

?? RS fairing is smaller than RT. So less wind resistance. But the RT will keep you dryer. (Completely dry actually , at speed)

[Eddieb]

It is an ex-MOT machine, 1985 model.

I've searched the net but not found anything helpful. Anyone have any suggestions or know of a reputable mechanic who can advise me?

Hi Winston

As with everyone else, welcome aboard.

For bits for the older Bm's get hold of Kerry at Motohaus in Auckland, (Motohaus on here) he knows a fair bit about the 80's and earlier models and has hands on experience with Ex-MOT R80's.

I found with my old R80G/S with the inlet trumpets removed out of the airbox (How I got it) the bike rev'd a lot quicker and had a noticable amount more go at higher revs, but was a lot more peaky with a sudden rush at about 5k revs.
The only problems with that mod is the inlet trumpets have to be cut off rather than removed as they also act as a seal for the airbox around the inlet tracts to the carbs, so it's a one way mod unless you have spares.

[Winston001]

I found with my old R80G/S with the inlet trumpets removed out of the airbox (How I got it) the bike rev'd a lot quicker and had a noticable amount more go at higher revs, but was a lot more peaky with a sudden rush at about 5k revs.
The only problems with that mod is the inlet trumpets have to be cut off rather than removed as they also act as a seal for the airbox around the inlet tracts to the carbs, so it's a one way mod unless you have spares.

Hi again everybody. I'm not sure what the etiquette is here regarding old threads so go ahead and abuse me. :bash:

Summer's here and the time is right for riding in the streets.

I just wanted to repeat my thanks for everybody's advice. I haven't actually done anything yet - except for trying Eddieb's tip regarding the air intake. Took off the trumpets (detachable upon close inspection) yesterday and either the bike is louder or it accelerates better. Both I suspect. :mega:

So that is a simple mod which might herald others. Anyone have thoughts on different pipes? I suspect the standard mufflers choke the bike's breathing.

[Milky]

We may well have some aftermarket pipes here if you want - I will check in the morrow. My old man used to do services on the MoT R80s when they were in operation, so we have about 5 genuine MoT tanks if yours is too expensive to repair.

[Milky]

Oh and etiquette is something along the lines of - If there is valuable info to be added then it is fine. Dredging through old threads to post drivel isn't greatly appreciated

[Ixion]

We may well have some aftermarket pipes here if you want - I will check in the morrow. My old man used to do services on the MoT R80s when they were in operation, so we have about 5 genuine MoT tanks if yours is too expensive to repair.

Just on the off chance- he didn't do services on the MoT Suzuki GT750's did he. Anything on the big Suzuki two smokers, I'm interested to hear. Best bikes ever made.

[Beemer]

There is a guy in the Manawatu called Trevor Homes (not Holmes) who has an R80RT that he has apparently done quite a bit of work on to make it perform better. My husband is at a trail ride today so I can't ask him what's been done to it, but he reckons it's pretty impressive. I think the bike is currently up for sale too.

[Milky]

Just on the off chance- he didn't do services on the MoT Suzuki GT750's did he. Anything on the big Suzuki two smokers, I'm interested to hear. Best bikes ever made.

Not that I know of. When were they running those as patrol bikes?

[Dadpole]

Not that I know of. When were they running those as patrol bikes?

Back at the dawn of time (1972/75). Only the lucky cops got them. The not-so-lucky ones got the mighty GT380 instead. With the full gear (screen panniers etc) they were a sad sight trying to keep up with the play.