Kz750 odometer

The thing almost has to be LH threaded.  There are probably some stripped threads, probably on the knob. 
I would grab the knob with pliers and pull & turn (clockwise, while holding the shaft with pliers or vice grips).
The 750H meter assy is almost identical to my motorcycle. I'm assuming the meters themselves should be pretty much the same, but everything else is identical.

1981 KZ650-CSR speedometer. in case yours is different.


ps:  Krylon ColorMaxx satin sea glass is a good match for the green inner housing.

Here is my 1980 Kz750E speedo, and trip knob. It’s a left hand thread. 

 

Alright guys, I’ll make some kind of video to prove to you guys what’s happening to mine. The 650CSR gauge does indeed look identical. I’ll try the pull and twist method but I’ve boogered the knob as much as I want to go booger it so I’m not going to destroy trying to pull it off especially when I have already achieved my main goal of resetting the mileage and cleaning it up. 

Got it opened, cleaned to my satisfaction, and COMPLETELY reassembled, re clamped the band and everything. Put it on the bike and 2 main issues. One larger than the other. 
1. the headlight out bulb on the tachometer stays on. Not a super big deal but still very odd that with the LEDs it stays on, all other lights work beautifully. 
2. the big issue. The speedometer doesn’t show any speed over 10 MPH! It still tracks distance great. I pulled the lower half of the speedometer cable and hooked it to a drill to confirm the gears in the lower box were still functioning properly. I was also suspiciously missing 2 longer screws that hold the main assembly inside the housing to the backing. So I am hoping that I reinserted a wrong screw somewhere not allowing the needle to completely rotate. But now I have to re-bend the band back open. Dang. But at least it looks good. 

If you replaced the “headlight out” warning bulb with an led you might have to add a load resistor to it or just leave that as an incandescent. I upgraded to all LED on my ‘78 1K LTD. If I put an LED bulb in the “brake light out” warning, which is similar to the “headlight out” it would glow dim. Putting the incandescent bulb back in everything worked great. 

As for the speed tracking it works off magnet driven by the axle gear drive through the speedo cable. The cable could be slipping with the addition load of higher speeds. I have a hard time thinking that a longer screw/bolt touching the magnet drive would effect higher speeds. I’d think the opposite. At lower speeds the drag from the screw/bolt would stall the magnet drive, I would think once speeds increase and overcome the drag from the screw/bolt the speedo would start to register. Just my thoughts. 

Alright what kind of load resistor do you recommend for the headlight warning bulb?​​​​​​ 
As far as the speedometer goes we will know as soon as I open it back up again. Didn’t have any time today but probably by tomorrow or Friday it should be done and we can open it up and see what’s going on. 

Before you open it. Pull one of the screws out, I’ll measure the ones in mine and let you know if it the issue. 

Contact these guys.

www.superbrightleds.com/search/led-products/load+resistor/

Pulled it apart and I was kind of correct. The screws that hold the blue backing to the whole headset we’re swapped with a smaller pair that held the internals together. However that was not my issue. My issue was the needle had been bent down and was contacting head of the screw that is visible on the face. With that fixed, and running the gauge with a drill, it works properly now. Now on to other things like shimming the needles and figuring out the best route for my fuel lines coming off the petcock. 

That makes sense. I thought you were talking about the screws holding the mechanism to the blue plastic lower (back) shell

 

You are correct I was taking about those as well however those were not the issue here. Although like I said I did put those in the wrong place. Just an FYI for anyone looking to LED swap their KZ750 or alike. These are the bulbs I used for the warning lights. You will need
1 blue(high beam)
1 green(neutral)
2 red(brake/oil)
1 white(headlight)
Warning bulbs

i chose not to do my turn signals to not create a problem with the reduced load and then them not working properly but if you do, then 2 more amber warning lights will fit the housing. 

These are the bulbs I used for the main speedometer/tachometer lights. You will need 4 of the color of your choosing. 
Large bulbs

and this is the resistor recommended to me by superbrightleds to turn off the headlight warning bulb that will light up constantly after the LED swap.  Resistor

I replaced my turn signal build and this LED flasher made them work as normal. It worked wrong the first hook up . I switched the two wires and was fine. LEDs are polarity specific. 

www.superbrightleds.com/moreinfo/flasher...nic-flasher/779/833/