Petrol spec and exhaust noise

ROBINCROFT

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Ado fellas,

nice easy one regarding my recently acquired (2012) 1200 GSA tc.

Find the handbook a little confusing regarding petrol. I wish it would just relate to octane rating rather than terms like:
premium plus and premium unleaded etc. It states both but....
What should I be using 97 or 95 octane?

Also, the exhaust is a bit rorty is anyone aware of an after market can that is quieter?

Thanks

Charlie
 
CHARLIE HALL said:
Ado fellas,

nice easy one regarding my recently acquired (2012) 1200 GSA tc.

Find the handbook a little confusing regarding petrol. I wish it would just relate to octane rating rather than terms like:
premium plus and premium unleaded etc. It states both but....
What should I be using 97 or 95 octane?

Also, the exhaust is a bit rorty is anyone aware of an after market can that is quieter?

Thanks

Charlie
Click to expand...

They'll run fine on 95 but are smoother low down, do more mpg and are generally slightly nicer to ride on 97.
 
For commuting and running around 95 will be fine. However there's no doubt in my mind that the bike runs better on 97 and whenever I'm out of the gridlock of the south east I nearly always put 97 in.

The TC exhaust is indeed loud, plenty of threads on here about it. Cheapest fix is decent ear plugs
 
TC loud - you having a laugh!
I have to be so careful when filtering with the GS compared to the Ducati with fire breathing termi's - I could set off car alarms when I passed in that :-)
 
Hi Charlie, I had the same noisy (to my ears) exhaust problem recently. I'd de-catted my standard can and found that after 13,000 miles or so the standard can was way too loud at motorway speeds and the drone really got to me after a few miles.
However, I've recently fitted one of THESE full systems and found it to be a great improvement. The full stainless system junks the flappy valve so you don't have to worry about that seizing up either. :thumb2
Almost forgot, mine is an '11 plate GSA.
 
I find there's a bit of resonance from 2500 to 3000 revs with my decatted headers, standard can, no flappy valve. So if you're thinking about removing the valve this might be a consideration. Otherwise I find the standard can pleasantly loud for an OEM device and if I didn't wear earplugs and did a lot of low speed riding it might be an issue, but I do, and I don't and it isn't. And my bike also runs better on 97 octane but I couldn't say whether the fuel consumption is affected.
 
I removed flappy valve and de-catted my front pipes.

Noise never really bothered me much, but the bike tended to backfire or pop a bit.

Fitted a Remus tri-oval titanium can which is a bit quieter, sorted out the farting and seems to have helped back-pressure and in my opinion the engine braking.

As for fuel, always use the 97RON stuff.... Tesco Momentum not available in Northern Ireland. But it is 99RON and really improves the bike when I'm across in Scotland. Engine runs quieter and smooth as a sewing machine. Try it if you can source it near you.
 
Low octane petrol will detonate in a high compression air-cooled engine so its fitted with a knock sensor to retard the spark timing and 95-RON is nothing special. The late spark throws more heat (and noise) down the exhaust so might be slightly more noisy to use than high octane fuels. Not that I can tell any difference.

Better quality fuels allow the spark to fire the fuel at the best point for the engine to extract the heat. This give more power and better mpg by reducing exhaust gas temperatures. The engine runs smoother, gives more power and the exhaust valves have an easier life. It's also cheaper per mile at any speed so posh petrol is the least cost option.

If you have the time to watch this, the full story is explained and all sorts of other stuff. It's about the Mini A series but the principles are the same.

https://www.youtube.com/watch?v=ow5cGV7bXCw
 
I won't use supermarket fuel if I can avoid it. I use Shell Power something as often as possible. Bike does run better and certainly after it was remapped by HillTop, they recommend use the best fuel available.
 
I prefer Shell Optimax, but find Tesco 99 has been fine. The bike hates Asda and Morrisons 95 with stalling, chuntering and feel like there's a cork in the exhaust.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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