I can't remember anyone ever asking what the best rpm and/or gear was on a motorcycle to optimize fuel efficiency. Most people with sub-500cc motorcycles only ever want to know how to make them more powerful or go faster.

Quote from: SAFE-T on April 23, 2013, 01:43:37 PM

I can't remember anyone ever asking what the best rpm and/or gear was on a motorcycle to optimize fuel efficiency. Most people with sub-500cc motorcycles only ever want to know how to make them more powerful or go faster.

I don't know how to take this.. haha.  I bought the bike to commute.  Hence, I want to be able to drive it as efficient as possbile.  I am just used to a car and have the mind set that 4k+ RPMs is hard on an engine and hurts fuel economy.  This is something I am getting over and am getting used to.

Don't think too much about it CC. It's a whole nother animal than a car. Don't worry about wringing it out from time to time, but don't thrash the motor either.

.... Mmmm yes.... When I ride my bike alone I feel so fast ... Wen I ride with the mates who nearly all have litre bikes or custom street fighters with big power .. Or metric cruisers.... Open roads I feel slow again.... Till we get to the mountain twisties .... Then somehow we all level up again  ... The GS is much more flickable a lot of the time ... For me anyway ....

And filling up every SECOND fuel stop .... That kinda shits them too!! .... Bahahahahaha

Thanks a lot again guys.  And yea I heard these bikes are agile.

Quote from: CCmatters on April 23, 2013, 03:57:53 PM
I don't know how to take this.. haha.  I bought the bike to commute.  Hence, I want to be able to drive it as efficient as possbile.  I am just used to a car and have the mind set that 4k+ RPMs is hard on an engine and hurts fuel economy.  This is something I am getting over and am getting used to.

lolol.... well, it isnt so great on fuel economy, but you have the manufacturer's official word on what hurts the engine:
redline @10k rpm.
  (edit: sheesh people, dont take 10k so litereally.. look at the actual Red Line on your tach?! )

3k-6k is just stretching its legs

If you want good fuel econ, keep it around 3-4k and you'll be good.

trying to accelerate LESS than 2k without clutch, and you are hurting the engine I think. "lugging"= bad.

mmmm 10k ... not disagree... but on occasion i have been 'up it for the rent' .. and left my shift just a little long... bounced the needle to 11.5 ish ...

i dont do it deliberately... and wince a little each time... maybe once a month ... (yeah yeah i know i'm a bad person and should be more responsible/sedate  ) .. but ... no bad issues yet...

Hahaha... ok so cruising at 5-6k rpms isnt a horrible thing. noted.

Stock GS turns about 4800 rpm indicated at 60 mph indicated in 6th gear so:

4800x50/60= 4000 rpm at 50 mph in 6th

4800x80/60= 6400 rpm at 80 mph in 6th

GS was designed/geared to cruise at 4-6 or7k rpm

Performance wise, little is to be gained by revving a bike or car more than 10% past the peak HP which is at about 8500 rpm for a stock GS.  When you are accelerating and up-shift at about 9k the revs drop to about 7k in the next higher gear which puts you right around the top of the Torque curve.  That's why I say best performance is had in the 7-9k range and I ran my 97 GS like that in the mountains for hours on end.

But for everyday running about or commuting to work/school/etc the 4-7k rpm range does the job nicely and economically.  Takes some time getting use to it on your first bike, my first bike CB400T turned about 6k at 60 mph in 6th and I thought it was screaming down the road and had no power to pass.  I traded it in 6 months and 6k miles later on a CB750K which cruised down the Interstates smoothly and quietly but the truth is I just didn't know how to ride the 400 yet.

Quote from: CCmatters on April 24, 2013, 07:24:16 AM
Hahaha... ok so cruising at 5-6k rpms isnt a horrible thing. noted.

Cruising along at 5-6k RPM, your GS500 is about as far away from its red line as a typical car is when it's parked.

GSJack's info was about as good an explanation as you're gonna get 

Very nice Jack, thank you very much.  Honestly I regret saying I didn't think it was strong enough.  Now that I have gathered all of this info I took it out for an hour ride today and i was cruising with MORE than enough power.  I am going to ride it for another week or so up around where I live then I think I am going to start to commute with it.

BUT... it is still having an idling issue.  After riding all that time I parked it and left it on in neutral and it idled find at 1.25-1.5k RPMs for 15-20 seconds and then started to slowly bog down.  And I parked it 5 - 6 times throughout my trip around and some times it would idle fine for a little while and some times it would just shut off right away.. It's frustrating.  Haha.  I need to have someone look at it or something.

You said it's a 91? I would suggest an air leak around the carb boots between the carbs and the head. Personally, I would just replace them and the little orings all at once and be done with it.

Ok well.. if it isn't 1 thing, it's another.  And I would also like to use the term "when it rains, it pours" in my situation.

So I was at work yesterday and we got a severe weather storm.  Well it rained so bad it wore the dirt out from underneath my kick stand and my bike fell over.  Well it layed there for like 4 hours because tehre was nobody home to pick it up (i found out bc my grandma called me and she is 100lbs so obviously it wouldnt budge) and I couldn't leave work.  When I got home I picked it up and did a quick inspection and there was nothing damaged, it was just covered in mud.

Went out today to try to turn it on and nothing.  It turned a few times and then wouldnt even turn.  And now it just clicks, which is what I would assume is the starter, if it does anything at all.  I DID check the oil and it is full and you can tell it was just said, as described by the last owner, that the erl was in fact just changed but it DID smell strongly of gas.  So.. any ideas?

Look at the battery first, if it laid that long with the vent side of the battery downward most of the acid could have drained out if it's a conventional lead/acid battery which would account for it being dead.

Also where was the gas petcock valve set, if on prime a lot of gas could have drained thru the carbs into the engine but if set to "on" or "res" there might not be much in engine, float valves in carbs won't stop flow with bike laying down.  Set the bike up straight and check the oil and smell it for gas.  Is there a lot more in there than when you checked it recently?

Might cost you a new battery and another oil change to make it right.  Need to get a piece of wood or stone or something under that kickstand if you have to park it on dirt.

I smelled the oil and there was gas in it AFTER it was laying.  So you think it's a dead battery?  SHART.  I heard they were expensive.  How do I check to see if the acid drained out?

It's under the seat.  Unhook the cables and pull it out to check it, there's marks on it showing where acid level should be.  If acid level is OK then might just need a charge or jump to get going.  If there's a lot of gas in the oil it should be changed before starting.

Ooook well I just had my GFs step dad look at it who is a mechanic and he bled the carbs for me and said that the gas smells like crap, so that probably means it has been sitting in there a while.  I did see the acid on the inside and there was none leaked so he is taking it and putting it on a charger for a little while and then i am going and picking it up in a little to see if it starts up.  As for the oil, I am going to try to get it to run so I can drive it somewhere to get the oil changed.  How hard is it to change the oil in these things?  I am sure i can find a video or something that shows how it's done but you know.  I need a service manual! hahaha.

No!!!

If gas got past the carbs and into the motor, don't try to start it. You can do some insane damage to the motor.

If you can change oil in a car, the GS is probably 100 times easier than that.

I dont know if it is too much gas tbh.  I will have to go and sniff it again. lol.