21 replies to this topic

[TOMMO0302]

My fuel consumption is awful!!! In the region of 20mpg it would seem for a fairly standard 1275 A+ with electronic ignition, LCB and RC40, K & N air filter element and thats about it.

I know i need a rolling road tune-up, but is it purely the wrong/worn needle/jet that is causing my issues or are there other factors? I have set my timing to 5 BTDC, have had the colourtune on it and it is a nice bunsen blue flame at idle and slow acceleration but under any medium to heavy acceleration its just yellow which leads me to believe that the needle is totally wrong or the jet worn etc?

So with regards to Rolling Roads, how important is it to go to a mini specialist and why? Because i only really have Mini Speed around here and you will only ever get on thier RR during the week (when i work obviously). Is it simply to do with the availablity of needles and other parts or will any rolling road place be able to accomodate a mini?

[Jammy]

Download a copy of WinSU and check which needle it suggests against your engine spec.

Moved to Technical...

[TOMMO0302]

OK, will do, but is there much point in purchasing it if i intend to take it to a RR anyway? Basically, i havent been before so dont know what happens. Will they always strive to mod your current needle to suit your engine or just supply and fit another if they have it?

And what will the differences be between taking to a mini specialist and a non mini specialist be?

Cheers for any advice...

[Bass Man]

Have you checked the plugs after a run? If they are black and sooty set the mixture a bit leaner. Probably wouldn't be recomended but you could keep doing this until they are a nice brown colour.

[TOMMO0302]

I have checked the plugs yes and adjusted the mixture accordingly, basically i had it too lean the other day (indicated by poor running and needing choke out) so richened it up just enough to avoid those problems, but the fuel consumption is still shocking hence thinking more needs to be changed than just the mixture.

Have you ever had your daughters mini on a RR and if so where did you take it?

[Big_Adam]

May I ask how you drive your mini?

If your like me (lead foot) then the fuel consumption is C**p no matter what you due.

[TOMMO0302]

You may of course ask, i would describe it as spirited, but definately not planted at all times.

May i ask what mpg you consider c**p?

[Big_Adam]

You may of course ask, i would describe it as spirited, but definately not planted at all times.

May i ask what mpg you consider c**p?

My mpg is always c**p. More money in the tank means less in the wallet. Damn student life.

[Gr4h4m]

I do about 100 miles to £10 and I run a 998, 12G295 head and twin 1.25" carbs, 1.75" peco

[Bass Man]

Have you ever had your daughters mini on a RR and if so where did you take it?

No, but I understand there is a good place in Molesey somewhere. I probably won't get it done unless it is really bad. I need to fit a new main jet and give the carb a good clean, then I will get it done on a gas analyser. It is doing 30+ mpg at the moment, performance wise it is a bit gutless, which actually suits me with her license only being 3 weeks old!!

[Bass Man]

I do about 100 miles to £10 and I run a 998, 12G295 head and twin 1.25" carbs, 1.75" peco

That's about 43 to the gallon!!!!!!! Not a lot wrong with that!!

[biggav]

From reading the Vizard bible, i interpret what is said as follows....

The "perfect" needle will differ from engine to engine and even 2 engine of identicle spec may require different needles... though you may have ideal mixture at various points along the needle you may also have blips of idle and rich along it.... with a rolling road they can compare fuel air mixture throughout the rev range, select a needle that is slightly lean across the board and then file bits off it until it's near on perfect.... but this also takes time and a few attempts to get right... also, file too much off and it's too rich and you cant ad bits back on..

[Jimmyarm]

In response to the original question, you need to take it to someone who is familiar with both SU carbs and the A series engine (and what happens when you tune it !).

So basically, yes you do need to take it to a Mini Specialist

It is well worth taking a day off to get it done

[Bass Man]

Vmaxscart is the place in Molesey, haven't been there but I read some good stuff somewhere....

[Big_Adam]

Either that or get your own needle and start learning. :P