speedometer off??

[lucky6man]

well crusing around the streets i know well. i have come to notice cars passing me or me having to go 50 or 55 to keep up with cars in a 45 zone. i know they are not all speeding so whats going on? is it possale for it to be off what could cause this? and how do i fix it?

[md86]

Speedos are inaccurate , that's just the way it is . But MOTORCYCLE speedos are NOTORIOUSLY optimistic , sometimes up to 12% . Best thing you can do is find one of those staionary radars and clock yourself . Yeah , it's normal , and sometimes correctible . OR you could just get used to it !

[The CyberPoet]

If you have a pre-98 Kat, disconnect and clean/lube the speedo cable. It runs from the instrument panel down to the front wheel gearing sprocket. Also check to make sure the end that mates to the instrument panel is square -- if it's rounded off, it won't be turning the speedo sufficiently (in which case it needs to be replaced).

If you have a 98+ Kat, check your sprocket tooth counts -- if it's not stock, the difference affects the speedo reading (which is taken from the output shaft of the tranny, effectively the front sprocket). Two products that I know of exist to correct this on the 98+: SpeedoHealer and YellowBox. The third solution is printing a permanent sticker that overlays your existing speedo dial, but I don't like that solution.

Good Luck!
=-= The CyberPoet

[lucky6man]

thanks cyber its a pre 98 so ill go give cleaning a try

[MIBagentQ]

my kat750 is a 2002
According to my GPS, the speedo is approximately 6% off

basically when the speedo indicated 140 km/h, the GPS indicated 132 km/h

My old 250 was 10% off so an indicated 140 km/h was actually 127 km/h

[The CyberPoet]

thanks cyber its a pre 98 so ill go give cleaning a try

Disconnect the cable at both ends when you go to clean it -- WD40 works well as long as you leave it hanging up to drain out any contaminants that might be between the sheath and the cable itself. If it comes out looking extremely dirty or rusty, you may want to consider replacing the cable.

KNOW THIS:
The standard calibration on the front wheel is based on the stock tire that was on it at the time it shipped from the factory, and a change in tire size (outter diameter) can play into the speedo error. The stock legal requirement is for the speedo to be off between 4 and 10% (over-reported speed compared to actual speed) -- this is to compensate for tire wear, tire variations between brands and to ensure that at no time will the bike ever under-report the actual speed (which could open the manufacturer up to liability for speeding tickets and possibly even accidents).

my kat750 is a 2002
According to my GPS, the speedo is approximately 6% off

basically when the speedo indicated 140 km/h, the GPS indicated 132 km/h

That's a normal percentage. See the above about intentional false reporting.

Cheers
=-= The CyberPoet

[stevnmd]

I don't know why more manufacturers don't set up their speedo pickups like Aprilia. My Tuono's speedo is virtually DEAD ON. The MOST I've seen it off is 1.5 mph and that was in triple digits... (most likely due to the tire actually expanding outward from rotations)

The speedo pickup is mounted near the rear rotor and actually uses the rotor mounting bolts to determine speed.

[katlover]

If you have a pre-98 Kat, disconnect and clean/lube the speedo cable. It runs from the instrument panel down to the front wheel gearing sprocket. Also check to make sure the end that mates to the instrument panel is square -- if it's rounded off, it won't be turning the speedo sufficiently (in which case it needs to be replaced).

If you have a 98+ Kat, check your sprocket tooth counts -- if it's not stock, the difference affects the speedo reading (which is taken from the output shaft of the tranny, effectively the front sprocket). Two products that I know of exist to correct this on the 98+: SpeedoHealer and YellowBox. The third solution is printing a permanent sticker that overlays your existing speedo dial, but I don't like that solution.

Good Luck!
=-= The CyberPoet

How does the speedo correcters work? I want to buy one, but I'm not sure what I would have to do.

[The CyberPoet]

If you have a 98+ Kat, check your sprocket tooth counts -- if it's not stock, the difference affects the speedo reading (which is taken from the output shaft of the tranny, effectively the front sprocket). Two products that I know of exist to correct this on the 98+: SpeedoHealer and YellowBox. The third solution is printing a permanent sticker that overlays your existing speedo dial, but I don't like that solution.

Good Luck!
=-= The CyberPoet

How does the speedo correcters work? I want to buy one, but I'm not sure what I would have to do.

They take the electronic signal coming off the tranny output shaft (98+ Kats), run it into an electronic box, do a bit of timing math (to correct the signal speed) and then generate a new signal that then goes to the destination of the original cable instead. Let's say your electronic speedo is 10% off and you're driving 55 mph (which we can, for purposes of illustrating the issue only -- these numbers aren't right, is 200 signal pulses per minute). The speedo corrector reads the 200 signal pulses, and regenerates 10% more than that, 220 signal pulses per minute, which then gets sent to the bike in the place of the original 200 pulses per minute.

Obviously, this doesn't work on the pre-98 Kats, since they are directly driven by a gearing sprocket and rotating cable (i.e. - non-electronic). For them, your basic choices are to install a different gear sprocket (which can be impossible to find), a different resistance spring for inside the speedo (again, probably impossible to find), or place a new face on the gauge with the corrections printed on it (such as a stick-on-label with new spacing between the markings).

Cheers
=-= The CyberPoet

[Yellow]

Re: speedometer off??

well crusing around the streets i know well. i have come to notice cars passing me or me having to go 50 or 55 to keep up with cars in a 45 zone. i know they are not all speeding so whats going on? is it possale for it to be off what could cause this? and how do i fix it?

Around here everybody (little old ladies excepted) are speeding... and the cops don't really bother unless you're driving recklessly. I know my speedo is off, but it can't be 50 % off (I usually read the traffic pace at 75-85 km/h in the 50 zones here)...