Not good MPG on GSPD

[cobbster]

Would be interested in your thoughts on bad MPG - between 36 - 38mpg. well I think it bad.

I have been on several runs, using 3 tanks (to get the above figures)worth of fuel and returning the above mpg.

The bike starts, stops fine, runs well (in my opinion) pulls strong etc.... nothing seems up.
I have had luggage boxes on some of the time but not always. I don't think I ride the bike hard (my opinion)

I have took the plugs out and there are spot on (there is slight blackness to outer ring of plug) but thats being very picky.

I cannot see any leaks, I've ran the bike all day, filled up, so the bike has'nt been left for weeks without use. The taps to the tank are turned off and not left on.

My probable next step is to have a go at the carbs?

Your thoughts/advise please?

 

[toadjam]

i,m jealous

bit more than i get .


ya not thashin it enough .

 

[(RIP) Proff]

Try closing the throttle slightly when cruising, also avoid just opening throttle wide, let it build up rather than have it just sucking a mixture it can't use effeciently...
I get 45 mpg two up and I'm a fat Bastard...

I also don't hang around

 

[Rob Farmer]

Mines a 93 100PD,

36 to 38 is normal. I think the best I've ever got is 48 on a steady run.

 

[Ogmios]

I'm getting to the point of considering selling mine.
various reasons irrelevant to this thread - but also as i simply cant afford to run it as a commuter.

1990/'91 model R100GS.
does low 30's in town
but about 50mpg as soon as it sniffs an open road.
i'm not exactly slow on a country road either

but nigh on €30 to fill and that dont last a week.
EVERY boxer i've had (3 so far) was the same, no matter what i fiddled and fettled with.
sign of the times - but it's getting too much for me.
my Guzzi can do 45 /50+ per gallon-regardless of how and where i use it.
Do Dellorto carbs make THAT much difference?

~~
Depressed of Dublin

 

[pete.keys]

I'm getting only about 32 on my R80g/s that has a Sexton upgrade to 1000cc and dual plugged



My journey is 15miles each way on straightish country roads & dual carriageways - but i am doing 85 to 90 most of the way which is is probably a bit to quick. The economy is disappointing though




I do try and commute slower to take it easy on the bike and save fuel ... but i just can't do it

 

[Flipfly]

Mine does about 70+ mpg.




































Usually cause it's on a trailer and it takes about 70 miles before it leaks a gallon over the road

 

[pete.keys]

had me going for a moment

 

[fayeslane]

I reckon 45 mpg touring is pretty good. 35 ish when having fun

You can try a complete carb rebuild which won't hurt but may not make an appreciable difference depending on their current condition. Other than that -new plugs, new air filter, timing check, tyre pressures etc etc

 

[bernardofeio]

I’m getting 6,0 – 6,5 L/100ks in my R100GS

I do almost 400kms/week and the consumption doesn’t change much even with some off road (60kms/day)

10,5:1 Wossner pistons with MAHLE barrels and std Bing carbs

 

[(RIP) maverick]

R100T - gets around 45.3 mpg over the last 6 fuel ups. Best consumption I got was 54 mpg.

Recently replaced all the gaskets + o-rings on the carbs.

R80TIC - 45.7mpg on average

This is running the bike between 4500-5000 rpm on a Essex - Central London commute.

I use http://www.fuelly.com to track my fuel + mileage.

 

[Sean Kelly]

Hi

Sexton built 1000cc RT bottom end and barrels with twin-plug 80GS heads, easy 45mpg 70-80mph motorway cruise. Needle heights set with half-spacers on the dyno to give correct fuel-air ratio.

Fuel consumption is awful when junk from the airbox builds up and blocks the little holes in/around the main jet.

Sean

 

[Mike the Bike]

Binding brakes ?

 

[(RIP) Proff]

Hi

Sexton built 1000cc RT bottom end and barrels with twin-plug 80GS heads, easy 45mpg 70-80mph motorway cruise. Needle heights set with half-spacers on the dyno to give correct fuel-air ratio.

Fuel consumption is awful when junk from the airbox builds up and blocks the little holes in/around the main jet.

Sean

Thats why all of mine have the stupid white tubes removed and replaced with a small filter where it comes into the airbox. [pref fine metal mesh]

Binding brakes ?

FFS this is the airhead section, we don't have brakes.
Just gentle retardation devices,,

 

[fayeslane]

FFS this is the airhead section, we don't have brakes.
Just gentle retardation devices,,

Also known as - bearing warmers

 

[Ogmios]

...
FFS this is the airhead section, we don't have brakes.
Just gentle retardation devices,,

what
you mean Moderators

 

[Kenny]

what
you mean Moderators

The Moderators warning light came on in my bedroom alerting me to this post....I'm watching you M'Laddie

 

[Beemerboff]

When everything is tuned right and riding is sensible, or the roads are wet as it will be in the UK, 20 km /litre - 56 mpg should be possible, but as the tune fades and the pace comes up a bit 16 km/l - 45 mpg is more likley.

In Oz quality of petrol has a major influence - ethanol has aroung half the energy of petrol, so E10 will be 5 % dowm right away, and I dont think there is much energy in toulene or the other crap they use to doctor up the old stale junk we get here, in South Australia anyway.
When I actually get it the top price BP Ultimate gives more than 5% better mileage, but not all Ultimate pumps seem to bbe connected to the right tank-----.

Mileage seems best just after a carb rebuild and service, float levels just right, unworn needles, all the passageways and pin pricks clear, timing spot on, etc.

As Richie M has found , some bikes will take a bit more advance than others,
so adding a couple of degrees might be worth a try, and a stiff dose of injection cleaner might clear out the passageways in the carbs - I have noticed the difference after using it on my lightly used bikes.

 

[slowkitty]

38 mpg (UK) city riding. On highways I get 51 mpg at 120 km/h tops. R100R.

Will the 40mm Bings be worse?

Cheers

 

[Ogmios]

The Moderators warning light came on in my bedroom alerting me to this post....I'm watching you M'Laddie

's alright - i'm the designated decoy Tosser tonight.