I've got my R80G/S apart and I'm getting ready to completely rebuild the top end.

I found a 1000cc kit for this bike that bumps the power to 67 HP and claims to reduce fuel consumption. It's offered by Eurotech, which is a very reputable dealer - anyone have any thoughts on this kit? The compresion ratio is raised to 9.5:1 - is this a little too high to stay reliable for 50-100,000 miles? Any idea what octane fuel will be suficient to keep it running healthily at that compression ratio?

Here's the kit:
http://www.eurotechmotorsports.com/f...=11%2056%20101

Thanks,
Wright

I would go for 1000 cc clyinders from a late 1980s or 1990s R100 with heads from a R100-s,rs,rt 1978 to 1984 those have the 44mm intake valves. Then 40mm bings.
Stay with 8.5:1 pistons. 9.5:1 is too high for modern gas. You would eather have to get aviation gas or dual-plug the heads.

Hi,
What did you go for ?
I choose to stay with the 800cc since 1000cc will be too much torque at winter.
I have CC-highflowvalves (San José BMW is not populare with me however)and will have the heads shimmed down to raise compression ratio.
9.2:1 standard 800cc pistons (models 1978-1980)with pistonrings for nicasil barrels (you can have pistons made at Venolia instead - much better !) Will give me about 10.2-10.5:1 => recon that will give me about 60-65Bhp, and revs instead of torque.

Then when you fix the heads - ge the BMW car valves, 46mm and highflow intake valves and stay with the 38mm intake => is supposed to make a "hell-of-a-drifference". A guy has just broken in this converson in Sweden on his newly converted boxer. These valves are 5mm longer, so you have to have them "cut down" and a new grove on the valvestem. They will fit the standard 44mm intake seats nicely - with no more modifications (!).
You will have to take up the correct valvesize in the piston head though.

The 67 conversion kit, to which you can keep your 32mm carbs, is affordable in germany - but very expensive elsewere.

By the way - scrap the bings. Get Dell'ortos (I favour them)or Mikunis, CC-favours them (www.sjbmw.com). You will be surpriced how much better the bike runns with those carbs !


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Albert Lindberg, D.C.


[This message has been edited by Grant Johnson (edited 08 October 2002).]

It really depends on what you are using the bike for. However, I did talk to one fellow who made this modification. He complained of very hard (to impossible) starting with the stock starter. When I talked with Eurotech, they recommend a different starter for use with this kit. Just something to keep in mind if you go this route.

Hey folks,
Thanks for the responses. I should have noted that I ended up selling the R80 in favor of a shiny new R1150 GS after much debate and calculation of how much it would cost to get the R80 built up to what I wanted. I think I'm actually saving money

Cheers,
Wright