Tachometer cable issues

[Skywatcher]

MF 203. I want to get the tachometer gauge operational again, but there’s 2 problems.
One is that the female screw on the cable won’t tighten completely to the housing on the engine. Gets to about 3/4 on.
Two is that the cable’s ‘key’ rod can be hand spun when inserted into keyhole of the engine tachometer housing assembly. I’d assume it’s supposed to turn only when the engine is running. Maybe the cable rod is too short?

 

[flying belgian]

MF 203. I want to get the tachometer gauge operational again, but there’s 2 problems.
One is that the female screw on the cable won’t tighten completely to the housing on the engine. Gets to about 3/4 on.
Two is that the cable’s ‘key’ rod can be hand spun when inserted into keyhole of the engine tachometer housing assembly. I’d assume it’s supposed to turn only when the engine is running. Maybe the cable rod is too short?

You might try wrapping the male threads with alum foil. take a piece of wire and use it as a measuring device. stick it in to see how far you have to be. Just do the math.

 

[miangus]

Not to be rude but are you putting the correct end on the engine. I have tried to install the cable reversed and the treads on the tachometer are just a bit bigger. Also, I cannot recall how the Diesel is but my 202 gas has a separate insert on the driven end where it connects to the generator.

 

[Skywatcher]

Not to be rude but are you putting the correct end on the engine. I have tried to install the cable reversed and the treads on the tachometer are just a bit bigger. Also, I cannot recall how the Diesel is but my 202 gas has a separate insert on the driven end where it connects to the generator.

This cable has very obvious sizes on each end, one is 1” the other is about 1/2”.

I got it on, I removed the fuel tank to access it easier and replace some of the fuel lines. So, it turns out that the cable rod has about 3/8” of give inside the sheath. On the rod right inside the flare there’s a little plastic sleeve that sits in a notch of the cable. I grab the tip of the rod and pull it out, insert it into the keyhole. The plastic sleeve fits into the housing assembly, which holds it in place. A pair of slim needle nose pliers helps this process.

As for the thread, I don’t know why it won’t tighten all of the way on. Since the purpose of the cable thread is to hold it in place, I cut an aluminum coin into a notched washer like the photo. Then did the same thing with some gasket material. Stagger the notches like piston rings, it’ll help keep the oil in. Installed it, and it tightened the cable flare like it’s supposed to. It might leak some oil, depending on amount I’ll decide if it needs another gasket material layer.

Only problem is that the cable may slide out of the engine keyhole and into the gauge’s keyhole since it’s got that much give. Time will tell.

 

[miangus]

On my 202 the end with the keyhole has a short adapter which converts the keyhole to a square drive. That's the end that goes into the generator. My parts book for the 150 with the Perkins diesel shows a cable with a square drive on both ends, no keyhole drive like you show. Sorry I am not much help. I think you may not have the correct cable.

 

[MKinON]

If it's the Perkins 3 cylinder diesel, I think there is an intermediate piece that goes into the engine drive first, into which the cable inserts. At least that's how it is on our MF30 diesel. No idea why it's not threading on fully though.