Correct Tappet clearance for R 80 G/S engine

**Giacomo** · #1 26 Nov 2004

Hi from cold and rainy Italy..

I set the tappet clearance on my newly bought bike this morning, and I notice a low valve ticking noise that wasn't there before...

Mind you the valves were quite shut before doing this so it could be just me not really used to the sound that the engine should be making.

In any case my question is: what is the correct tappet clearance for this bike, everyone seems to say 0.10mm for the intake but for the exhaust I can't figure out if it should be 0.15mm or 0.20mm

The bike has done about 70,000km and the last owner claims to have changed the cam chain recently.

Thanks for any advice!

A.

**Grant Johnson** · #2 26 Nov 2004

.10 and .15 is correct for the R80G/S engine. I've always run that in mine and it works fine.

.10 and .20 is for the R100.

Note that you want to also check the rocker end clearance, it should be .05 + or - .02mm clearance.

See this thread for more: http://www.horizonsunlimited.com/ubb...ML/000291.html

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Grant Johnson

Seek, and ye shall find.
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One world, Two wheels.
www.HorizonsUnlimited.com

**Giacomo** · #3 27 Nov 2004

Thanks for your reply...! I reset the exhaust tappets to 0.15 and the sound is much better!

I just wanted to ask you one more thing. I've been using the bike for nearly a month now, and I'm not too happy with the fuel consumption I'm getting about 14-16 km/l (sorry I've no idea how to convert to MPG) As I mentioned already, the tappets were shut tight, could this also have been affecting fuel consumption? Any hints on how to improve things a little?
Thanks again !

**Grant Johnson** · #4 27 Nov 2004

That sounds about right for fuel consumption, depending of course on in town vs highway etc.

It's an OLD engine design, and is not especially good for fuel mileage. The new F650's for instance gets MUCH better fuel mileage, can be as much as 50% better.

DO replace the slide needles and jets, they wear and increase fuel usage significantly. Also make sure the float level is correct - floats should be dead level.

------------------
Grant Johnson

Seek, and ye shall find.
------------------------

One world, Two wheels.
www.HorizonsUnlimited.com