Fuel requirments ?

...should I be using regular grade petrol in my K3...???...

...maybe that is the cause of some of the "valve train" noise...

[Craig380]

If you're in the UK, the lowest octane fuel you can buy is 95 RON, which is WAY above what Suzuki specify as a minimum.

If you're outside the UK, what octane rating is your 'regular' fuel? It's worth noting that in the UK, what we call '95 octane' would be rated as 91 in the USA & Canada, because the UK uses a different method for grading the fuel.

The owner's manual states 91 RON (i.e. the UK measure) as a minimum, so in the US and Canada that's the same as 87 octane.

[SV650rules]

Unless you have a grey import the maker normally adapts engine CR and timing etc. to suit locally available fuel. In Asia the fuel can be pretty low octane but if bike was supplied with European spec 95 RON will be fine unless compression ratio on your engine has been increased ?? I would not call Pinking or knocking 'valve train noise' - they normally occur on a hill in a high gear (low engine revs) and you can check by selecting too high a gear on a hill and opening the throttle (this will check for clutch slip at same time LOL).

...thank you for the thoughtful and informative replies...

...I am not used to that ****...

...I believe 87 is the rating of commonly available "regular" grade fuel round hea', and that is what I have been using, and will continue to use...

...I have not noted any pre detonation but sometimes it is hard to tell when you are half deaf...

...I assume you realize the "lower" grades of fuel have more energy or power or whatever than "higher" grades of fuel...???...

...if your bike can run on it, the lower grades of pump "gas" will yield more performance and higher horse power than "premium" grades, as octane is basically a flame retardant...

...but you knew this, right...???...

...anyways, my piglet has a totally stock everything, that isn't jerry rigged or missing...

...the stock engine is more than enough to overwhelm the suspension and brakes...if you need much more engine than this, imho you've bought the wrong bike...

...sorry aboot the dots, if they annoy...I'm afraid we are quite beyond rehabilitation at this point...

...what got me twigged was reading someplace aboot how the new SV has a slightly reduced compression ratio to allow the use of "regular grade" fuel...I was all like WTF...!?!...

[SV650rules]

While it is true that lower octane fuels have more of the explosive stuff in them than high octane the problem is when you compress the fuel/air mixture the lower octane stuff explodes when you don't want it to (before the spark tells it to), and this causes problems with extracting the power because it reduces the compression ratio you can use when using lower octanes (it also seriously damages the engine because it tries to push the piston back down the way it came up without letting it get to TDC like it normally does) . By adding 'anti-knock' agents to boost octane (used to be lead but is now other stuff like ethanol and methanol) the fuel becomes more controllable and higher compression can be used, and it allows timing to be altered (advanced) for better combustion.

The power of Merlin aircraft engines was increased a lot when 100 octane fuel (with loads of additives LOL) became available from USA during WW2.

...thanks for the edification...I knew I didn't have it quite right...

...all I really have for experience is anecdotal, but Rick Yacoucci ( Turbo Rick) used 87 octane pump gas to set a land speed record for a stock class on his Hayabusa...it went fastest on 87...

...he actually used the cylinder head off my wrecked 99 Busa as parts were in short supply for Busas in those days and he had burned up his head...

http://www.turborick.com/main.html

...I don't want to compress anything more than it is already...I don't think this bike would be any faster on race fuel...

[SV650rules]

Originally Posted by Hapo

...I don't want to compress anything more than it is already...I don't think this bike would be any faster on race fuel...

http://www.speedhunters.com/2015/04/...about-ethanol/

Good news is adding ethanol to low octane can increase octane rating and power, bad news is to see those gains you need to inject more of it (10:1 air/fuel instead of almost 15:1 for normal fuel). Otherwise the ethanol is just a cheap way of increasing octane rating.

...we have been trying to get that stuff removed from our fuel over here...

...it seems to cause a lot of issues, mostly related to moisture absorption...

...it is currently @ 10% at most locations though the govenment is striving to get it up to 15%...