Speedomitor seems to read a bit off

Today me and my dad were riding our motorcycles and he was following me. I have an XJ550. I was going what I thought was 60 mph and my dad kept falling way behind. He has a Voyager. I asked him when we got to our destination why he was going so slow and he said he was going around 60 and he didn't want to get much faster. He thought I was going about 70. Now, either his speedomitor is off or mine is. I did test it one more time with a car tonight and i was still going faster than the car when supposedly we were going the same speed limit.

Has anyone had any issues with this? I have had my odomitor and tachomitor cables fall out due to vibrations, but we'd screwed them back in and put lock-tight on them so i didn't think it would be an issue. Any ideas?

 

i'm having the same issue, i'mma take my speedo apart again (like the 5th time) and see if i can't lube it up and fix it.

I'll let ya know how i make out.

 

I've owned many metric bikes and there is not one that had an acurate speedometer. They all showed 4-5 miles faster than I was actually going. That's always been a standard on these bikes. I've owned Yamahas, Suzukis, Kawasakis and Hondas and they are all the same.
The first metric bike I've heard of that the speedo was dead on is the Yamaha FJR sport touring bike.

 

easy done, you & dad go through a speed trap @ 70 & see who gets a ticket.

 

my speedo is off by about 40km/h.. and it keeps goin up as i brake lol

 

When you say "metric bikes" I'm assuming you mean in km/h. All (well almost all) vehicles in Australia run on metric, so I'm wondering why speedo's in metric in the U.S would all be out. Two things come to mind.
1. We send all our crap ones to you. :twisted:
2. It has something to do with the rotation of the Earth...like water going down the drain hole the other way 8O


Yes....I'm kidding :lol:

 

When my xj750 speedo says 60mph it realy means 68mph. A LEO told me this.

 

You know, I was thinking that mine was a little slower than what it actually reads. When I'm on the expressway, it reads 70 mpr... but it really doesn't feel like I'm going 70, not to mention that cars a still flying past me. So I was truely wondering if it was just me.

 

Thats because from my experience alot of the Ill. drivers around the shy town area have a minimum speed of 80 in there cages LOL... I used to get down that way about twice a week and northern Indiana and Ill. drivers just fly It's a wonder I didn't see more pulled over but I guess the cops don't mind either...

On topic now It seems my speedo has begun to read faster than I am doing that or I did some great carb work it seems the rpms are 800-1k lower then they were at certain speeds before I took everything apart.

 

Ok, i just got done tearin the meters apart. I did find what was making the speedo lag. I'd use pics but i can't find a blowup of the assembly.

Once you get the actual speedo assembly out of the white (mines white) housing, flip it upsidedown. You'll see a metal guard protecting the bowl that is physically attached to the needle assembly. There was (best way i can describe it) a sap like substance gumming up the movement of the needle assembly against that guard. After cleaning up that sap, and reassembling, the needle moved free and worked properly.

I didn't oil anything while i was in there, because i don't have sewing machine oil here for 1.) and 2.) i wanted to see if it did it again.

Hope this helps someone else

 

KrS14, sewing machine oil is the ticket so long as it is the clear stuff. Do not use 3-in-1 oil, it is vegetable oil base and will gum things up again! I'm still trying to figure out how to non-destructively disassemble the speedo myself so don't feel alone.
Speedometer inaccuracies are normal folks. If you don't use exactly the same original tire every time you swap out, you will get an error. This is also compounded by the wear and age of our machines. Taking the meter to a speedometer shop is not cheap and you would need to re-calibrate it every time you put new rubber on the back. I've noticed personally as much as as 10% difference on my machines, sometimes not even linear! This is why most patrols don't quibble when you run with the speed of traffic. Speedos are notorious for being inaccurate at higher speeds.

 

Get a GPS or throw on a bicycle speedometer and you will know your exact speed.

For modern bikes there is the speedo healer:

Speedohealer

 

Use a stopwatch and milemarkers.
55mph=65 seconds
60mph =60 seconds
65 mph = 55 seconds
Outside of this range it won't be accurate.

My XJ1100 is dead on.

 

The "sap like substance" was the original lubricant. Sewing machine oil OR precision machine oil (sold for model railroad locomotives) will work fine USED SPARINGLY. For the record, what that stuff was when in its original form was something called "non-fluid oil." NOT grease--grease contains fibers and is sticky, non-fluid oil is just that, and different from grease. We used to use it in typewriters and adding machines back in the day. I wouldn't know where to find it anymore except maybe a speedo shop?

 

i tested my bike with my gps, bike reads 5km over actual. not in a hurry to fix it, it cuts down on speeding tickets

 

Shame on you, Robert. You should know the speedometer doesn't give a rat's pattotie what the rear tire is doing. It's tied to the rotational speed of the FRONT tire on the XJs.

BTW, my speedo just gave up the ghost yesterday (Note, I said speedo, and not Speedo - fret not my marble sack/bathing suit is still fine). Seems it's the cable or take-off hub and not the gauge (which is about 5% fast on my bike - just sold a spare that read slow by quite a bit - so they're all over). I get no spinny at the upper end when under way. Got to dig deeper tonight.

 

Hey man...you spelt truble wrong :wink:

 

(off-topic)
Heh, that "A:" part is actually a quote from a board luminary. Better forgotten, but you can find the source if you're really interested.

It's somewhat mean-spirited. Maybe I'll change it.

 

Hey Bigfitz, I picked up my fine oil from a sewing machine shop. Light, clear oil with a long tube to reach those difficult lube points.