I have recently bought an SR 125 as a cheap means of travel and alternative to my car. After buying the bike I have changed the oil, cleaned and oiled the air filter, changed the spark plug, cleaned the carb and checked the chain tension.

My problem is that I am only getting 59MPG. I am led to believe that i should be getting 80MPG+. Can anyone shed any light on what might be wrong? It seems to be running ok. Maybe a tad rich at 3/4 throttle but nothing serous.

The bike will also sit comfortably at 50mph but struggles to do more than 60mph. I am 6'3" and 15 stone but surely that wouldn't make that big a difference?

Very frustrating as I bought this to save me money, an I'm not saving as much as I would like.

Thanks

Aye andy 60mph thats about it mate, if you were 10stone [ like we were in the 70"s ] it would pull 70mph....

check the brakes aint binding, but I think your 15 stone is the prob,,

Aye andy 60mph thats about it mate, if you were 10stone [ like we were in the 70"s ] it would pull 70mph....

check the brakes aint binding, but I think your 15 stone is the prob,,

I understand the top speed issue is my weight but I should be getting more than 59 MPG, surely?

Thats pretty much what my sr125 does too. About 100-110 miles per tank. Im nearly 15 stone too!!

At 6'3", regardless of weight, you'll also be acting as quite a sail I'd imagine. That'll affect things a fair bit too.

Regarding MPG. I have to admit, it sounds a little low. When I had my YBR that was up around 100mpg.

Did a quick search on Google and those that have used Fuelly on an SR125 are reporting around 80mpg for a 1998 model. A fair bit lower at 67mpg for a 1993 model. Not sure how accurate those figures are mind...

There is a top forum member on here, AndrewElvisFan with an SR. Maybe drop him a message for advice?

Thats pretty much what my sr125 does too. About 100-110 miles per tank. Im nearly 15 stone too!!

Maybe that's it but I'm still not convinced. Anyone else please?

At 6'3", regardless of weight, you'll also be acting as quite a sail I'd imagine. That'll affect things a fair bit too.

Regarding MPG. I have to admit, it sounds a little low. When I had my YBR that was up around 100mpg.

Did a quick search on Google and those that have used Fuelly on an SR125 are reporting around 80mpg for a 1998 model. A fair bit lower at 67mpg for a 1993 model. Not sure how accurate those figures are mind...

There is a top forum member on here, AndrewElvisFan with an SR. Maybe drop him a message for advice?

Thanks. I have PM'd him

to get your mpg I suggest a little compromise in your riding style

something like this should do

Hi Addy!

As far as speed goes, that is about right. Sits comfortably at 50, with no wind I can get 60, and downhill, wind behind me and lying on the tank I have had 70!

Mpg doesn't sound quite right though. Mine is a 94 with nearly 47k on the clock and I am getting around 75 mpg on average.

I use premium petrol which has made about 7-8% difference. I have also fitted a 15 tooth front sprocket instead of 14. This hasn't made a great deal of difference to mpg but has to the top end speed. I live near Cambridge so haven't too many hills to worry about with the lack of power going through the gears.

My 5'7, 11 (ish) stone frame makes a good sail so I can imagine 6' plus acts as an effective parachute!

to get your mpg I suggest a little compromise in your riding style

something like this should do

And that is how I managed 70!

I've just read your original post properly and see you've already cleaned the carb. How old is your bike? Is the exhaust in good order - if it is coked up it would cause the engine to use more fuel. What sort of riding do you do? My daily commute is mostly in 5th gear, but when I go out for real enjoyment I use twisty roads and all the gears which effects my mpg.

Just a thought - have you any extras fitted like heated grips or lights that are more effective than factory fitted? Anything electrical can have an affect on power output to the rear wheel.

Hi Addy!

As far as speed goes, that is about right. Sits comfortably at 50, with no wind I can get 60, and downhill, wind behind me and lying on the tank I have had 70!

Mpg doesn't sound quite right though. Mine is a 94 with nearly 47k on the clock and I am getting around 75 mpg on average.

I use premium petrol which has made about 7-8% difference. I have also fitted a 15 tooth front sprocket instead of 14. This hasn't made a great deal of difference to mpg but has to the top end speed. I live near Cambridge so haven't too many hills to worry about with the lack of power going through the gears.

My 5'7, 11 (ish) stone frame makes a good sail so I can imagine 6' plus acts as an effective parachute!

Thanks for your reply. mine is 2002 with 13000. I will try premium fuel. can't see it making that big a difference though

I don't think my bike has the power for an extra tooth sprocket, although i need to check what' on it now. What are the standard sprockets front and back?

While I'm on. Does your bike also feel unstable on any kind of bend?

thanks

Just a thought - have you any extras fitted like heated grips or lights that are more effective than factory fitted? Anything electrical can have an affect on power output to the rear wheel.

No, nothing like that at all.

Standard sprocket on the front is 14, think it could be 49 on the back. I'll check the specs and let you know if it's any different.

As far as stability goes when I first got mine, I had a couple of hairy moments cornering - small amount of wobble - but I'm guessing that was my lack of experience and perhaps fighting with the bike. I quickly learnt to lean further into the corners as opposed to 'steering' into them. Somewhere on here there is a thread on counter steering methods, but basically, forget driving a car, if you want to turn right, imagine a piece of string at 45 degrees to your handle bar and push down into that on the right. If you are leaning with the bike, your centre of gravity will be lower and you should find tight bends smoother.

Also bear in mind the SR only weighs in around 120kg so sidewinds, bumps in the road and draughts from other vehicles will impact on how smooth cornering will be.

Standard sprocket on the front is 14, think it could be 49 on the back. I'll check the specs and let you know if it's any different.

As far as stability goes when I first got mine, I had a couple of hairy moments cornering - small amount of wobble - but I'm guessing that was my lack of experience and perhaps fighting with the bike. I quickly learnt to lean further into the corners as opposed to 'steering' into them. Somewhere on here there is a thread on counter steering methods, but basically, forget driving a car, if you want to turn right, imagine a piece of string at 45 degrees to your handle bar and push down into that on the right. If you are leaning with the bike, your centre of gravity will be lower and you should find tight bends smoother.

Awesome, thanks. I reckon my size on such a tiny bike doesn't help either

Also bear in mind the SR only weighs in around 120kg so sidewinds, bumps in the road and draughts from other vehicles will impact on how smooth cornering will be.

Also bear in mind the SR only weighs in around 120kg so sidewinds, bumps in the road and draughts from other vehicles will impact on how smooth cornering will be.

yeah it's when it hits a bump or groove that it feels wobbly. it's unsettling

And if you find your footpeg scrapes as you negotiate bends, in addition to having anal reflexes, it is a good sign you are going to fast!!