Upgrade R80 motor to 100?

[Nelson]

#1755

Evening all. I’m a new member but was a member of the Register about 12 years ago. I assume this forum is fairly new because I was unaware of it last year when I joined Kiwibiker.

I have an ex-MOT R80RT which I enjoy but don't use as often as I'd like. Took it to the Brass Monkey a year ago.

If there is a problem with a fully faired R80 it is lack of power. Lovely comfortable bike but tops out around 150kph. That's not a problem because I pretty much stick to 110 but it is frustrating in a head wind or on a steep hill. Not quite the passing power I'd like.

So I've been thinking about upgrading the motor to a 100. Is this worth doing? I've been told that the R80 is a smoother motor than the R100. The bike vibrates a fair bit but clear mirrors and not uncomfortable.

Any thoughts are welcome.

Cheers
Winston001

[Dave Ross]

#6195

Hi Winston,
welcome to this forum. I can give you my 10 cents worth, but I am not an airhead expert. Personally I would not bother upgrading and old RT to 1000cc spec, unless you can get the parts cheap and you can do the work yourself. I could imagine that doing such an upgrade to an old engine might put stresses on parts that aren't used to being stressed, unless you do up the whole engine while you are at it.

Maybe you would be better off selling the bike and buying something more powerful. Unless of course you enjoy a challenge and are looking forward to getting your hands dirty.

I am looking at buying an R80GS for adventure rides and for this application the power of an R80 is sufficient. Of course the odd Hp2 rider may disagree.

[Dave Morris]

#6196

most of the guys on hair have oil heads and don’t know what a real bike is. 😳

I posted ya question to the BrooC the man from Ozfailure who forgot to go home from Noo Plymooouuuuth and this was his answer.

""""""Speaking as one who has owned 3 R100GS, an R80RT,an R100RT, & now an R80G/S (the last of the great 'slash' beemers!) I would say go find some R100 lungs & bung em on as soon as ya can, they have to be about the MOST cost-effective performance mod I've ever thrown money at!

"My G/S now has a set & they did it a world of good, more grunt thruout the range & NO downsides I can identify except the not unreasonable costs . .. with careful shopping you should find a pair for around $500, toss in some fresh rings if they need it & a light hard-hone to help em settle in (ignore those who tell you that Nikosil cant have or doesnt need honing ~ BMW themselves issued a special hone for the job, so they orter know!) .. . & mebbe have a go at doing it yourself unless you are a total hamfist, just ask lots of silly questions ~ & try to sort the silly answers!

As to vibration, every bike seems different, & mine has no more vibration than previously, & is smoother than some of my stock R100's have been . . ..oh, & as far as I know the bottom ends are all the same so you wont be over-stressing anything . ... I didnt even need to rejet!

Go fer it, I say . .. . . getting rid of the turbulence-vibration over the top of the fairing will be a bigger challenge (unless yer a dwarf!)
BrooC in NP ;-)) """""

I can supply u Brooc E ing mail should you want it

bellsj@xtra.co.nz

and Koko has seen the light and is buyng a eal bike 😀

[Dave Ross]

#6197

I found this thread on ADVrider, its got some good pics. The guy is doing up an airhead and replacing the internals as well.

http://www.advrider.com/forums/showthread.php?t=165707

[Dave Morris]

#6198

Kokopelli wrote:

I found this thread on ADVrider, its got some good pics. The guy is doing up an airhead and replacing the internals as well.

http://www.advrider.com/forums/showthread.php?t=165707

please note that the site Koko sent u is upgrading to a 1050cc and not the normal 1000cc. so don't be put off. bruce bought some barrells pisttons etc off a person i know and did this mode with no hassle. there are heaps of sites out there that will help u do it.

u may want to consider the Holden alternator upgrade 2. only joking


steve

[Nelson]

#6199

Very helpful and encouraging. Where should I go to get the parts? Nothing available in Invercargill, too small. I don’t mind having a bike shop do the work but I don’t want to get stung for original parts from Germany.

Also would it be wise to put larger carburettors on too or is it just bigger jets that are needed?

[Dave Morris]

#6200

Winston001 wrote:

Very helpful and encouraging. Where should I go to get the parts? Nothing available in Invercargill, too small. I don’t mind having a bike shop do the work but I don’t want to get stung for original parts from Germany.

Also would it be wise to put larger carburettors on too or is it just bigger jets that are needed?

email me and i will tell u where u may get some

my email in another post

[Stuart Burns]

#6201

Motorworks in the UK used to sell a kit of secondhand parts to do this conversion. Might be worth talking to them as a last resort!. They’ve got a website, google motorworks should find it ok

[Dave Morris]

#6202

tonys wrote:

Motorworks in the UK used to sell a kit of secondhand parts to do this conversion. Might be worth talking to them as a last resort!. They’ve got a website, google motorworks should find it ok

yeah as a last resort and taking a second mortgage out for the exchange rate

[Author]

Posts