How to Adjust the KLX250S Speedometer
#17
Nice write up NoBrakes!
Another method I have used is simply to pry the needle off of the metal pin completely using two spoons so that pressure is applied to the needle evenly, and in a controlled manner. That way you reduce the risk of damage to the mechanism...
carefully rotate the counter-clockwise. Hold the base of the needle while you do this. It is just plastic that is pressed onto a metal pin, but it is pretty tight. Just don't damage your needle.
#18
ive done this mod on a scooter
I dont remember it having that large aluminum thing all I did was bend the spring somehow and it changed the needle position too
did it 2 times the last time was because the front tire was larger then stock
so just had to fine tune it again
was dead on with my gps too
I dont remember it having that large aluminum thing all I did was bend the spring somehow and it changed the needle position too
did it 2 times the last time was because the front tire was larger then stock
so just had to fine tune it again
was dead on with my gps too
#19
Fair question, I'll have to check that out
#20
Rotating the needle on the post will simply offset the reading, rather than changing the 'scale' of the reading. My speedo is about 10% off, all the way up and down the range.
Let's play a little math. Let's say the reading is 10% low: Indicated = Actual * 0.9
If you rotate the needle such that it adds say, 5mph: Indicated = Actual * 0.9 + 5
Given this, the indicated speed will be correct at one particular speed... a little simple algebra.
Set the Indicated=Actual...
Actual = Actual *0.9 + 5.
Actual(1-0.9) = 5.
Actual = 50mph.
At all speeds away from 50, the indicated speed have a progressively greater error. Given that we are probably most concerned with knowing the speed when in a fairly narrow range of speeds, and trying to avoid a ticket, this sort of error is probably OK.
If you want to have the speed accurate from 0 to 100 (yeah, right), then you need to do a proportional correction to the speedo, which might well involve changing the spring tension.
Let's play a little math. Let's say the reading is 10% low: Indicated = Actual * 0.9
If you rotate the needle such that it adds say, 5mph: Indicated = Actual * 0.9 + 5
Given this, the indicated speed will be correct at one particular speed... a little simple algebra.
Set the Indicated=Actual...
Actual = Actual *0.9 + 5.
Actual(1-0.9) = 5.
Actual = 50mph.
At all speeds away from 50, the indicated speed have a progressively greater error. Given that we are probably most concerned with knowing the speed when in a fairly narrow range of speeds, and trying to avoid a ticket, this sort of error is probably OK.
If you want to have the speed accurate from 0 to 100 (yeah, right), then you need to do a proportional correction to the speedo, which might well involve changing the spring tension.
Last edited by DigiSnapMark; 01-04-2013 at 03:20 PM.