Engine problem, gas problem or what?

[MotoDan]

I'm on my second tank of 91 octane gas and I started hearing some clicking / knocking sounds.  When I warm up my bike with the choke and let it idle around 2000rpm it would click / knock and drop like 500rpm and then go back up to 2000rpm.  It keeps doing this till i turn off the choke.  Is this a problem with the engine or the gas i'm using?  It's not a faint knocking it's pretty loud too.  Oh by the way, it's a 2004 with 500km on it so i'm still breaking in the engine.

[mp183]

Use regular 87 octane gas.  Engines designed for regular don't like high test.

[MotoDan]

Use regular 87 octane gas. Engines designed for regular don't like high test.

Really?  In the manual it says to use 91 octane or higher.

[Kerry]

I don't think it's a problem with the gas, even though I have used 85 octane (here in UT) for 2/3 of my bike's 30,000 miles.  (The rest of the miles have been on long-distance trips, and I can't seem to find anything less than 87 octane anywhere else!)

Anyway, back to the problem at hand.  How long do you let the bike warm up with the choke on?  Once the engine is FULLY warm it will tend to die at idle with even a small amount of choke.

I'm not sure what the clicking or knocking sounds would be....  Maybe just the engine bogging down as it tries to die.  Or maybe the bike is temporarily running on 1 cylinder because of a spark or mixture problem.  (Running on 1 cylinder makes a rather unique sound.)

What year is your bike, how many miles does it have, and what else can you tell us about its past?

[MotoDan]

I don't think it's a problem with the gas, even though I have used 85 octane (here in UT) for 2/3 of my bike's 30,000 miles.  (The rest of the miles have been on long-distance trips, and I can't seem to find anything less than 87 octane anywhere else!)

Anyway, back to the problem at hand.  How long do you let the bike warm up with the choke on?  Once the engine is FULLY warm it will tend to die at idle with even a small amount of choke.

I'm not sure what the clicking or knocking sounds would be....  Maybe just the engine bogging down as it tries to die.  Or maybe the bike is temporarily running on 1 cylinder because of a spark or mixture problem.  (Running on 1 cylinder makes a rather unique sound.)

What year is your bike, how many miles does it have, and what else can you tell us about its past?

Well it's a 2004 with 500km on it and that's why it's kinda worrying me.  Unless that's a characteristic of the gs.