Since the GS500 has a 10% speedo increase can you run the bike at 80-85 on the speedo (really ~75 mph)for about 1.25 hrs without hurting the engine in superhot  humid Louisiana weather?

I do it every day to and from work, I hope it doesn't hurt. I figure if they can race em around tracks at high speed for a couple of hours, it can't hurt my bike.

As this is lower speed than what is allowed here, I would not see a problem. Means cruising at 7.000 rpm, so what?

Just make sure your motor oil level is ok. Motor oil also has some cooling function.

I wouldnt worry about it to much. What type of oil are you using??
I would switch to a thicker full synthetic. For  track days, and hard rides on hot days I Switch to a 20/50. It lubricats better at higher temps than say a 10/30.

I have ridden my bike on a few 350 mile sportbike rides, were we only stoped  a few times.
after Consistant floging to try to keep up. I have lost almost no oil, and it still actually has a nice color to it.
I use Castrol actevio 20/50 for the summer, 10/30 spring and fall,
and a 5/30 for the winter. it seems to keep the bike well lubricated after some brutal rides!

Maybe re-jet the bike as well. If you richen it up things will run a bit cooler.

Other than that I dunno...

Micah

I use castrol gtx 10w/40;  maybe next time I will switch to 20/50 weight.  Thanks for the tip.

I use Castrol GTX also and have run it for almost hours at an indicated 80-90 mph.  Many times I'll go at high speeds for 225 to 250 miles without stopping.  Your butt will give out before the engine will.  The harder you run it the better it will run.

I ran Coastal 10-40 dino juice for 7000 miles burned 2 qts.  I am still running the same Chen Shin HiMax rear tire in a 130/90-17  with the taller tire I am running about 6000 in 6th gear at 80.

I concur with all of that, should not be a problem. Most manufacturers handbooks do caution against long periods without variance of the revs. As I see it such a thing could only happen if you had a road long enough, straight enough and level enough and I do not suppose there are too many of those about.

You are right about varying the engine speed.  I do that as a matter of principal.  Cuts down on the boredom.  It's also the key to successful speeding on the Thruway.

xaeniac:  i have a question:  are you saying that the speedometer is reading at ten miles per hour more than your actual speed?

is this a common problem that i just don't know about?

when it says i am going 45, am i really going 35?

It's usually more like 10%, rather than 10 mph.  (At least, that's what I've found on my bikes.)

So, at an indicated 45 you're going more like 40.5 and at an indicated 80 you're going more like 72.

No wonder all the cars on the freeway pass you like you're sitting still!  :lol:  (I say that from experience.  The first time I rode on the freeway I was flabbergasted that everyone seemed to be going 80mph!)

Wow, that is good stuff to know.  I was commenting to a co worker that everyone seems to be on my tail, and I am doing 5 over the limit.  I guess I need to get my butt in gear.

You'd think they would find a way to correct this.

I must be the unlucky guy, because at 74mph indicated, I'm doing actual 71mph... only about 4% off for me.

Quote from: xaeniacSince the GS500 has a 10% speedo increase can you run the bike at 80-85 on the speedo (really ~75 mph)for about 1.25 hrs without hurting the engine in superhot  humid Louisiana weather?

I don't know about anybody else, but I've lost total power on at least 3 occasions from sustained high speeds b/c the fuel petcock (the one attached to the gas tank) could not flow fuel fast enough to keep up with me. I eventually emptied the gasoline in the carbs. That totally sucks. You've been warned.

yup , one of the "few" gripes of the 'ol gisser

I have a 2002 and never had that happen.  I have a feeling they finally solved that.  In fact my year seems to have no know issues.  It took a while to warm up before I re-jetted but I just ran it with the choke if I was in a hurry.

that used to happen to me too.  after riding at high speeds for awhile it would start feeling like i was running out of gas, even when i switched to reserve, and eventually die on me.  i believe others have posted about this problem before.  stock petcock is pretty much a P.O.S.  someone, i think it was Kerry, posted about using PRI for long rides.  it works for me.

Quote from: Dorianfesthat used to happen to me too.  after riding at high speeds for awhile it would start feeling like i was running out of gas, even when i switched to reserve, and eventually die on me.  i believe others have posted about this problem before.  stock petcock is pretty much a P.O.S.  someone, i think it was Kerry, posted about using PRI for long rides.  it works for me.

Well, that is not an option for me b/c I removed the other P.O.S. petcock (On/Prime/Reserve) and all the vacuum tubes and put a straight fuel line to my carbs. That is how I know the fuel tank petcock is to blame.

Quote from: FlashI removed the other P.O.S. petcock (On/Prime/Reserve) and all the vacuum tubes and put a straight fuel line to my carbs. That is how I know the fuel tank petcock is to blame.

Somebody said something the other day that gave me a new perspective on the whole fuel starvation problem.  The gist of it was something like "When the throttle is wide open there is less of a vacuum to operate the ON/RES diaphragm in the frame-mounted petcock".

If this is true, then the following may NOT be true:

1) The tank-mounted petcock simply can't pass enough fuel through.
(Flash, you removed the vacuum system along with the tank-mounted petcock, so how do you know for sure where the problem was...?)

2) The hoses have a too-small inner diameter to satisy the high-speed fuel demands of our rip-roaring 487cc twin.

3) The frame-mounted (ON / RES / PRI) petcock simply can't pass enough fuel through.
(It MAY be able to in the PRI position, which is not affected by the presence or absence of a good vacuum.)[/list:u]

Can anybody confirm the assertion that

WOT = significant drop in vacuum?[/size][/b][/i][/list:u]

Hmmm.  I've only had one vehicle that had this problem.  It was a 69 Superbird.  With the stock fuel sustem it was starving for fuel at 150MPH.  I had to add a second pump and go to a 1/2 inch supply line.  Hope I don't have to do that to the GS.  There isn't as much room to work with. :dunno: