poor mpg?

[mr72]

Quick update.

Filled up yesterday after the first full tank (145 mi) on the 125 Jets and stock needles. I was careful to fill it to the same level or maybe slightly higher.

53.2 mpg !!!

And I didn't try to ride it gently. In fact, since I was wringing out the carb tuning I actually rode it pretty hard the last tank, lots more wot and 9k shifts as opposed to my normal slow and easy riding style.

So I think I solved it, quite by accident.

[Blueoval78]

I have an '89 GS500e, recent total carb clean and rebuild, stage 3 Dynojet, K&N lunchbox filter, stock exhaust.  Pilot screws 2.5 turns out.  Floats set to high end of spec.  (More fuel in bowls)  Mix of in-town, highway, hard acceleration and normal cruising on my last tank yielded 49 US MPG.  Bike runs absolutely perfect.  (Minus a pesky oil leak I posted about, grrrr)

[Meukowi]

Poor mpg? yes. 31mpg or 38 uk mpg, 7.4L/100km, made a short trip of 148km & 91miles, not wotting or city driving, just non stop road. How the heck is it that bad? Dynojet? it tells that mpg should be better with dj kit installed. Got 132.5 main, and kn box. Maybe because ive got bigger rear sprocket? had rpm around 5-6k on the trip. Bike rolls freely too, new bearings on wheels.. ideas?

[MaxD]

I checked mine carefully over a period of months, logging what the pump said over every fill-up.  I got about 52mpg.  Fuelly seems to average about 50, almost identical to the older air cooled Honda CB500.  I have seen some reports over 60 for the GS500, so I was a little disappointed I could not do that on mine.  Fuelly says the new water cooled CB500 gets about 62mpg average.  I believe the air cooled engines are designed to run a bit rich for cooling.  That is how small aircraft with an engine richness control are flown.  In the climb out, running at full power and slow since you are angling up, it is recommended to run full rich as it provides extra cooling. 

[Bluesmudge]

I've hit 60+ mpg a couple times with my 2006 GS500F but that requires siting at a steady 50 or 55 mph for the entire tank. A constant 70 mph yields ~45 mpg. Huge range. My 250 Super Sherpa is 60 - 90 mpg depending how you rid it. I think modern water cooled/FI bikes are much more consistent. Especially as you go up in displacement.

My wife's '18 CTX700 gets 62mpg no matter how you ride it.

Its worth noting that the $ savings goes down dramatically as mpg goes up. I use 60 mpg as the "it doesn't matter above this number" number. The gas used per mile is inversely proportional to miles per gallon. So a Honda Grom that gets 125 mpg isn't much cheaper to run than my 250 that gets 70 mpg.

Mr72, how has your MPG been since 2018? (wow time flies)

[mr72]

there was a super Sherpa for sale in Austin recently that had me tempted. if only I had more spare time and storage space.

Anyway, my mpg is probably not a reliable indicator of anything useful. Recently I had to go up to bigger jets and I'm also riding with big tires now and a 14t sprocket. Bike is raised up about 1.5" higher than stock including suspension and tires and I made the riding position more upright which affects wind resistance. And I don't really ride the gs on the highway anymore, and when I do ride it I'm a bit of a hoon because of how different it is than the triumph.

But. I checked it the other day and it's getting about 45 mpg on non ethanol gas. My air cooled 865cc triumph gets about 40-42 and its fuel injected and ridden much more sedately.

Man I really need to finish my home improvement projects and ride. It's been over a week. No time and no need to go anywhere without having to haul home lumber.

[MaxD]

A small fairing on the naked GS500's might be an mpg help and make the bike a little more comfortable on road trips. 

This short review shows a GS500 with what seems to be a Slipstreamer Spitfire fairing--in my opinion it looks pretty nice.

https://www.youtube.com/watch?v=dhIEtHu5Iec