I have just about come to the conclusion that it's possible my speedometer isn't working because the speed sensor is bad.
Only 19,000 miles on it... would seem pretty early for that kind of problem,.. but anything is possible. It is a '96 Sportster

Someone showed me where the sensor is (on top of the transmission)
Looks like it takes an allen wrench to screw the nut out...
PROBLEM is this.. the nut doesn't go straight into the transmission.. It tilts back toward the oil tank. I have found NO WAY to get a allen wrench in there so I can take the sensor out.
I was hoping maybe someone has done this and can tell me where to start.. or could look at their Sportster and see what they think.

This bike has been all chromed out.. I first thought I'll about have to disasemble the whole thing just to get to this screw. I has a chrome oil take cover on it.. but even if I take everything else off.... the bolt that holds it on sets "Behind" the chrome cover.. so even if I take off all the other chrome (pipes, transmission cover, etc.. still can't see any way possible to get to the main bolt on the chrome oil tank cover. I know many of you put chrome covers on your tanks.... surely it can't be "that" complicated.
Did you have to take off the seat.. of how do you go about it
Thanks for any help

 

cut a 1/2" off your allen wrench.

 

Yes, cut to fit.
I got a bunch like that...

Brett

 

I just looked at my bike.
Looks easy, without removing anything.
Cut an Allen wrench to length, put an adjustable wrench on the short side and turn....

Just watch the battery/power connections!

Brett

 

wow.. cut to fit might be the answer...

just went and looked... I can cut the end off the wrench.. problem is to fit into the nut opening and be secure,,.. the wrench has to fit down between two hoses.
The hoses are mechanically clamped together right above the nut. (not on with a hose clamp that I can remove) SO I can't move the allen wrench 'between' the two hoses..
I can take a screw off and move the other end of the hoses.. only about 1/2 inch.. (which only serves to put one of the hoses directly over the nut)
hhuumm

While I am bothering everyone.. this nut looks like it holds in an oval shaped 'plate'. The sensor looks like it is next to the nut. A wire runs out of this 'sensor' and back toward the rear of the bike.
Even if I get this sensor out.. where does that wire go and how is it attached ( is it plug in type deal...??)
Wondering if I get the sensor out.. if I can get to where I need to be to change it...??

Man,.. you guys that tinker on these things all the time sure have a bunch of tricks I am sure. I am sure you know what you are doing. I hadn't messed with a bike in 30+ years.. It's like starting all over.. LOL Appreciate the input you have given so far.
Me... I'm a car guy... building a street rod from the ground up. But I am building it so when I have to work on it in the future... I can GET to everything... LOL

 

It is plugged in under the seat.

Its easy to know what your doing.....buy the service manual for your bike.

 

yeah... service manual...
It's my Girl friends bike,.. and she is just "sure" she has it somewhere (you know how that goes... LOL)
Anyway she keeps balking at buying another one until she is 'positive' she has lost it...
I guess I can't blame her. I am on disability,.. and the government just helps us enough to get by.
And she was out of work for a year.. so her funds are all depleted also..

I may have to break down and buy one for her.. sure would save a lot of headaches...
I heard they cost $70 or more. Anyone know where we can get one for a lot less. Some months I have to decide between buying food or medicine... Thats why my street rod has taken so long.... it has been in a "stopped" state for 2 years now....
Maybe some day..??

 

On my bike, I could just shove the hoses out of the way.
The speed sensor likely works just like your typical abs sensor and crank sensor, little metal teeth move past a tip on the sensor and generate pulses the computer counts.
Sometimes they get metal fuzz on the tip that can be cleaned, and you can actually test them (ohm reading, o scope monitor of the pulses).

I would check/clean the connector under the seat first tho.

I wonder if the speed sensor is the same part as the crank sensor.
Might be a handy fix on the side of the road to swap them when the crank sensor craps out....

Brett

 

thanks for the additional responses..
yeah $29 is more like our price range. Thanks for that info..

I tried moving the hoses.. just to confined space.. They are pretty much as far 'in' as they'll go.. and not enough slack to pull them 'out'..

I think you are correct in how the sensor works.. Kinda sounds like what my local Harley stealer said when I had to stop by there yesterday.
He said something about it being like a little 'magnet' on the end.
First off I was going to try and get it our and clean it.. might be some 'fuzz' causing interference. It works perfect for about 5 miles when I got to riding it again.. then it just 'bounced' up and down a few times and then quit.
A couple time when I was riding and down shifted I saw it 'bounce' up and then fall right back down..
I was hoping since it did work.. then all of a sudden quit,.. maybe it'll be something easy and inexpensive to fix.
I figured maybe it was the contacts somewhere. Cleaned all the contacts in the 'dash' where the speedometer is... no luck.
SO yeah it could be contacts under the seat.. have to get that manual so I can educate myself...
thanks again

 

Yea, my speedo was buggerd up too. Tested and changed the speed sen. Stil no luch......Ended up being my Stator, Still don't know if the speedo problem will right its self.