
speedo
- firestormcrazy
- Posts: 24
- Joined: Sat Aug 23, 2008 5:43 pm
- Location: washington
speedo
help!!! i ve ran out of ideas and need some advice. When the speedo reads 30mph im only doing 25 and its doing my nut in. I have changed the speedo drive and the clocks and checked all the connectors and everything is ok but its still doing it
any ideas, cheers

speeding officer..... you sure?
- firestormcrazy
- Posts: 24
- Joined: Sat Aug 23, 2008 5:43 pm
- Location: washington
- firestormcrazy
- Posts: 24
- Joined: Sat Aug 23, 2008 5:43 pm
- Location: washington
Is the 25mph a real speed or is that what’s showing on some one else’s Speedo??
If its real speed say read off a sat-nav remember there’s always a in built error of around 10% and that’s usually on the optimistic side so you don’t inadvertently end up speeding so at 30mph on the clock the real speed would be 27 ish so 25mph is a bit under but not a lot
If your speeds been picked up of some one else’s Speedo then I would say that the gearing has probably been lowered with either a 15 tooth front sprocket or a 43tooth back in that case you would need a Speedo healer or revert back to standard gearing to correct the speedo
Fitting a Speedo healer is easy and programming them is a doddle as long as you follow the instructions word for word
I’m a law abiding citizen with no interest in braking the speed limit jim
If its real speed say read off a sat-nav remember there’s always a in built error of around 10% and that’s usually on the optimistic side so you don’t inadvertently end up speeding so at 30mph on the clock the real speed would be 27 ish so 25mph is a bit under but not a lot
If your speeds been picked up of some one else’s Speedo then I would say that the gearing has probably been lowered with either a 15 tooth front sprocket or a 43tooth back in that case you would need a Speedo healer or revert back to standard gearing to correct the speedo
Fitting a Speedo healer is easy and programming them is a doddle as long as you follow the instructions word for word
Me neverBeamish wrote:Warby has one also if my memory serves me correctly, seem to remember a top speed of 160mph stored in it



I’m a law abiding citizen with no interest in braking the speed limit jim


its big----- its red ------its throbbing and it’s a thousand CC
- firestormcrazy
- Posts: 24
- Joined: Sat Aug 23, 2008 5:43 pm
- Location: washington
Have to have a think on this one
But first thing are you positive your m8 Speedo is correct it could be his that’s out maybe check with a GPS/sat nav and check it at different speeds to it may be reading right at a higher speed
Don’t assume that a replacement part is working ok I spent hours one time on a car trying to get it to run right and it turned out I’d replaced a duff condenser with a new duff condenser
The Speedo works on the same principal as the tacho
The Speedo drive picks up a signal from a magnet/s on the output shaft in the gearbox then sends the signal to the Speedo say how many revolutions of the shaft then the Speedo displays the information as mph
Not a lot to go slightly wrong more likely not to work at all than anything else
There is a way of recalibrating the Speedo but I don’t know how it’s done “never had to do one myself†so probably have 2 go to a specialist and that’s going to cost
A speedo healer is about £65 and can be reset if you change ratios
But first thing are you positive your m8 Speedo is correct it could be his that’s out maybe check with a GPS/sat nav and check it at different speeds to it may be reading right at a higher speed
Don’t assume that a replacement part is working ok I spent hours one time on a car trying to get it to run right and it turned out I’d replaced a duff condenser with a new duff condenser
The Speedo works on the same principal as the tacho
The Speedo drive picks up a signal from a magnet/s on the output shaft in the gearbox then sends the signal to the Speedo say how many revolutions of the shaft then the Speedo displays the information as mph
Not a lot to go slightly wrong more likely not to work at all than anything else
There is a way of recalibrating the Speedo but I don’t know how it’s done “never had to do one myself†so probably have 2 go to a specialist and that’s going to cost
A speedo healer is about £65 and can be reset if you change ratios

its big----- its red ------its throbbing and it’s a thousand CC
- bikerpiker
- Posts: 1823
- Joined: Sun Mar 23, 2008 9:59 pm
- Location: Ayrshire - Scotland .
What about those road signs that flash your speed up on display on roadside when approaching villages,schools etc
I wonder how accurate they are ,i know when i approach the sign in a nearby village it displays 26mph when my car speedo is sayin 30mph
Most likely the signs will be accurate ,wondered if there were any local to you
stevie

I wonder how accurate they are ,i know when i approach the sign in a nearby village it displays 26mph when my car speedo is sayin 30mph

Most likely the signs will be accurate ,wondered if there were any local to you

stevie
- firestormcrazy
- Posts: 24
- Joined: Sat Aug 23, 2008 5:43 pm
- Location: washington
- firestormcrazy
- Posts: 24
- Joined: Sat Aug 23, 2008 5:43 pm
- Location: washington