2310D Tachometer Inaccurate

[tonyg2160]

Okay, in a previous thread(s) I've mentioned that I recently undertook the project of completely repainting my (new to me) Ym2310D. Before embarking on this project I only used the tractor to grade my driveway for about an hour. In this time, I noted what seemed to be accurate tachometer action, even up to operating range of 2000-2500 rpm (indicated by the tach). Now...upon re-installing the gauge cluster, my tach seems to only indicate a range of 0-700 rpm...no matter how much I "rev" the engine. I've triple checked and re-seated the cable in the back of the tach and all seems good. The cable is obviously spinning...even smoothly. It just seems to not register over 700rpm. I would only add that this 700rpm limit has only been observed sitting in the garage, in neutral, as I'm not ready to "roll it out" of the garage yet. Might the tach be somehow dependent on the tractor being in gear?

 

[Peter 315]

It should work in neutral , Does not matter if in a gear or not:confused3:

 

[normde2001]

no...

 

[tonyg2160]

Yeah, I didn't figure it would be. I think I even noted correct behavior in neutral previously. Any ideas on why the 700 limit now?

 

[Peter 315]

Did you or somebody drop gauge cluster ?

 

[tonyg2160]

Did you or somebody drop gauge cluster ?

No. Removed gingerly, re-painted and re-installed. Now that you mention it though...I haven't tried "tapping" on it.

 

[Peter 315]

Is the needle bent and hitting the cover, Did you paint the needle

 

[tonyg2160]

Is the needle bent and hitting the cover, Did you paint the needle

No. I just removed the cluster and taped off the gauges. I didn't remove the gauges from the panel. I painted the black plastic cluster panel. Tapping the gauge made no change. The gauge operates smoothly, but only seems to "register" around 700 rpm regardless of the engine speed. When engine off, the tach rests at about 100rpm maybe, slightly above "zero". Engine starts and the tach climbs to 700 or so. When killing the engine, the tack seems to stay around the 700 mark until the engine dies. In other words...once it gets up to 700...there is very little (if any) variance showing on the tach regardless of engine speed.

 

[California]

I 'repaired' a squeaky, jumpy tach by turning it face down and dribbling a little 'lock fluid', graphite in solvent, in around the fitting that the cable turns. That was all it needed to restore proper function.

The tach is a sealed unit so if that won't fix it, replacement is the only option. There are instrument specialists who could take apart and re-seal it properly but thats likely more expensive than a replacement tach.

But I would still suspect the cable too. Make sure it isn't stripped on either end.

 

[tonyg2160]

I 'repaired' a squeaky, jumpy tach by turning it face down and dribbling a little 'lock fluid', graphite in solvent, in around the fitting that the cable turns. That was all it needed to restore proper function.

The tach is a sealed unit so if that won't fix it, replacement is the only option. There are instrument specialists who could take apart and re-seal it properly but thats likely more expensive than a replacement tach.

But I would still suspect the cable too. Make sure it isn't stripped on either end.

Yeah, my gut is telling me that it may be the "other end" that's the issue. The funny thing is...it doesn't seem at all "erratic"...just doesn't register over about 700 rpm.

 

[Peter 315]

I wonder if the cable is forcing the mount on the gauge crooked and causing it to bind Is the cable back the same it was routed before

 

[tonyg2160]

I just checked it all out again. Both ends seat well. Cable spins freely, no binding apparent. When disconnected from the back of the tach I can feel the cable spinning (I wish I could say spinning at 700 rpm but I honestly have no idea), but I can't feel very much variance in the spinning end of the cable (with my fingers) regardless of the engine speed. In other words...it feels like the cable is ONLY spinning at 700 rpm for some reason, regardless of engine speed.

 

[California]

Hoye can sell you a tach cable (core).

Long ago when i bought one for a Chevrolet it was universal and came with a cutter to shorten and shape one end. Possibly a generic cable kit for a Japanese car would work - if its long enough.

 

[tonyg2160]

Hoye can sell you a tach cable (core).

Long ago when i bought one for a Chevrolet it was universal and came with a cutter to shorten and shape one end. Possibly a generic cable kit for a Japanese car would work - if its long enough.

I honestly don't think it's a cable problem. Does anyone know how the internals of the tach drive gear unit at the front of the engine functions? Could it be slipping there? I don't think the cable is "slipping" anywhere. Actually...I don't think anything is slipping anywhere. If it were, you'd think there would be more erratic behavior out of the gauge. It's rock steady at 700 rpm throughout the engine speed range, but yet it's not "stuck" at 700. It just won't go past 700 rpm and the cable doesn't seem to spin any faster regardless of engine speed. Doesn't make any sense

 

[Peter 315]

Does it look like this

 

[tonyg2160]

Yes it does.

 

[Peter 315]

You can take it off I believe its just a worm gear here's the linkYanmar Tractor Parts:

 

[tonyg2160]

You can take it off I believe its just a worm gear here's the linkYanmar Tractor Parts:

Is there oil behind it? lol

 

[Peter 315]

Is there oil behind it? lol

Maybe a little just have a rag handy

 

[4get gto]

I'm thinking you can check the cable and tech just by taking it out at the motor and putting a drill on it. That's if it's not the gear drive on the block.