another speedo issue

[edavi394]

Hi, I am having some problems with my speedometer. I had the same problem since the day i got the bike. the dealer even replaced the cable which didn't fix it and then they said it could never be fixed. I thought that sounded odd but I have just delt with it.

the problem is my speedometer is slow to respond. it is dead on once it catches up to the speed I am going. so if I take off and head down the highway and go say 65, I can be driving 65 for about 3 mins before the speedometer gets to 65. it just slowly keeps increasing until it gets there. it drops down at normal speed. but no matter how long I ride in a day it never responds fast while excelerating. I was told it had something to do with a magnet or something and they said it was cleaned and there was nothing else that could be done. Is there?


Thanks.

btw I did search the forms before asking this and I did not see someone with the same issue if I missed it I am sorry. I also read all the info in the tech tips and didn't see this issue there.

[bikerphil]

sticky speedo

Time to lube the speedometer. First, try the easy fix. Take the cable off the speedo and shoot some wd40 or equivilent up in the cable passage. This might be enough to set it straight. If not, take the speedo loose from it's bracket, flip it face down and put 1 or 2 drops of 3 in 1 oil in there and let it sit for 1/2 hr. If this still doesn't work, you're gonna have to take the unit apart. Remove the outer case and carefully remove the reed switch (very delicate) and the gears are behind there. Put a few drops of light oil on them. Last resort, eBay for a replacement unit.

[3Phase]

It's possible that the speedometer has too much grease in it. In my speedometer, a bunch of grease got between the internal driven wheel for the speedometer needle and the housing.

I posted some pictures after I 'unstuck' my slow, sticky, speedometer

Take a look, and good luuck!

Regards,

Scott

[edavi394]

Hi, thx for the replys. I will try those and see if it helps.

I was told the problem was where the speedo cable hooks there is a magnet that spins around to make the cable turn. and the magnet wears then there is not a way to fix it. I am sure even if the info was fairly accurate there would always be a way to fix it.
does anyone know what I am talking about or am I way off in lala land :P

[AlanB]

Hi ed,

The needle is turned by a spinning, cup-shaped magnet....... But the magnet shouldn't touch anything, and can't wear!

Don't use WD/40 near your speedo; it dries to a sticky mess, and will attract a ton of dust and fluff into the mechanism.

the hollow square which the cable goes into should spin really easily (test with a tiny screwdriver, or a matchstick!) If it does not, then the problem probably is (as bikerphil said!) either the brass bush where the cable enters, or the odometer gears.

Best of luck!

AlanB

[3Phase]

The speedometer magnet does not turn the cable, the cable is driven by the lower speedometer drive gears on the front wheel hub. The cable is connected to and turns a shaft in the speedometer with a magnet pressed onto one end of it.

The shaft and magnet are the only part of the speedometer that is physically coupled to the front wheel. If some part binds even lightly the magnet may continue to turn but tension will build. The speedometer needle will 'jump'when the tension is released, then it will drop down and steady for a moment or two as the drive component binds and rebuilds tension. Basically, if the front wheel turns then everything else must turn or something will break.

The speedometer indicator needle itself is driven by magnetic coupling. The needle is not physically connected to anything but a magnetically-driven wheel with a tension spring and it moves in much the same way as a
magnetic lab stirrer.

Put the stirrer in a beaker with nothing but air in it and the stirrer will rotate freely at a certain RPM at a given speed setting every time ~= normal speedometer.

Put a dab of grease in the center of the beaker and put the stirrer on the dab of grease and the stirrer may still turn but it will not turn at the same RPM at the same motor speed setting ~= slow/stuck speedometer needle.

Put the stirrer in any kind of clean or greasy beaker at all but bind/lock the stirrer drive motor and try to set it to any speed setting. If the motor cannot turn you will not only hear some unusual noises, you will eventually get to see all of the magic purple smoke leak out of the motor before it trips the circuit breaker or burns up ~= speedometer does not work at all/seized speedometer input shaft bearing/cable/lower drive assembly.


Regards,

Scott

[tarzan]

When I got my SG running the speedo was very slow to come up to speed.It also was slow going down.I had to take the thing apart and clean and lube it.The grease on the gears was stiff from sitting for 25 years.I had to remove the bezel too which is a pain.