Low octane gas

**NCR** · #1 16 Dec 2004

Hi,

Going to Africa with my XR650R next year.

The owner manual states that only +98 octane gas can be used. This may be dificult to find in some African countries ;-)

Is there a solution?? Shall I add something to the gas???

Thanks and regards,

NCR

**RichLees** · #2 18 Dec 2004

don't sweat it! we've ridden from Cape Town to Addis on 90 octane without drama. sure, you get some black smoke and we're only doing 100kmh on/off tar, but your bigger problem is going to be your butt - mine hurts!!!

**AllenL** · #3 31 Jul 2008

Is there any long term issues that you've found using a lower grade gas? Build-up in the carb, tank sludge?

**Sjoerd Bakker** · #4 31 Jul 2008

I have an older XL600R and it too runs problem free on any low octane gas . The problem to be expected from lower octane fuel is detonation , pre ignition, pinging. This can all be avoided by modifying your use of the throttle hand.No sudden full throttle bursts to get up speed, just slowly ease up and shift up through the gears to lessen the burden on the motor which should be kept spinning at its comfort zone. If you do detect the noise of detonation immediately shift to a lower gear.
Burning low octane gas should not entail black smoke ,this simply means the carb adjustment is off a bit, or the choke/mixture enricher is still on.
You can thus work around the low octane feul by being attentive to the motor sounds . High octane is only of benefit for high compression motors, it does not burn hotter or cleaner, .It just puts out more power because you can pack more air into the combustion chamber with higher compression

**pbekkerh** · #5 1 Aug 2008

Quote:

Originally Posted by NCR

Hi,

The owner manual states that only +98 octane gas can be used. This may be dificult to find in some African countries ;-)

NCR

Talk to a workshop. I don't know your particular model, but if the ignition timing can be changed, this will give you a little less horsepower, but also less sensitivity to detonation/pinging because of low octane fuel.
Maybe the compression ratio can be lowered, by f.x. an extra topgasket, giving the same effect

But as already mentioned, going easy on the gas and changing gear when pinging, will take you a long way too.

Poul