Engine/Drive noise....HELP

[Tepcro]

Hi I am a newbie to Goldwings so if this sound is normal you will have to forgive me.
I and my wife took a spin to Colorado (all over the state) and back, when climbing up mountains below 3K RPM I notice that my Driveline/Engine makes a noise that sounds kind of like detonation rattle.
At 1st I thought maybe I was just lugging too much which is still possible... but the bike makes that same noise when coasting down hill with the throttle closed. (Just a little throttle makes it sound better)
I wonder if it could be; valve adjustment?
Slack in the timing chain?
Driveline noise?
Now here's the info on my wing;
2001, 1800cc, 107,000 miles, Car tire on back, changed oil just before the trip 10/40 4cycle bike Valvoline oil

Yes we were a bit overloaded and that might have something to do with it, but it did seem to get worse with Colorado gas (ethanol?) I tried Premium and Mid grade gas too same thing

I'd appreciate any help

[Wingsconsin]

I ahve not had my GL1800 in the mountains (yet - going in August)
My experience is with my GL1500 which I rode all over Colorado several times.
Using higher octane gas does little for the fuel mixture at altitude.
In fact the LOWER 85 octane they sell in Colorado is formulated for altitude better.
Any Goldwing loves higher RPMs in the altitude to create horsepower due to the thinner air.
The Fuel Injected 1800's should be better as the O2 sensors will compensate for the mixture change -
If you have no issue at lower altitudes ...? then perhaps that is the problem?

Just my thoughts ...

[Tepcro]

Thank you Wingsconsin
I hadn't thought of the lower mixture being formulated more for the high altitude....
This sound that I hear is very hard to describe other than maybe a lugging sound.
I guess I don't know when I'm lugging this engine as it has so much power even at the lower end....
My Yammy likes 4K+ on the open road but I am reluctant on my wing to run higher revs even though it will do it, unless necessary. (or what it likes)

[WINGER3]

Welcome Tepcro, the 85 octane if just fine in Colorado Mt. altitude, but go to 87 at low altitude and she will run fine, lugging is easy to do as you said it has power down low and don't worry about RPM, Goldwings thrive on it, you won't hurt it, lugging it will, shift down when in doubt. Good luck and ride safe.

PS; I'v red lined every Goldwing I have owned and several 100 thousand miles and never a engine problem.

[Tepcro]

Thanks Winger3
I figured that I must have been lugging it.....It has so much bottom end on it that it feels right....

[baumedagn]

I try to never run below 2000 RPM. I read it somewhere and it seems to be a good rule of thumb