Temp Sender Thread

[urbantangleweed]

I'm sure one if you guys will know this, but is the thread on a YPVS Temp Sender 1/8th 27 NPT?

[midlifecrisisrd]

Usual argument will follow 🤣

As far as I can remember early is a straight thread and late is npt

Whether it's m10 x 1.00 or 27tpi I'll leave the others to comment

Steve 🤐

[JonW]

Jan 18, 2024 23:49:16 GMT 1 midlifecrisisrd said:

Usual argument will follow 🤣

As far as I can remember early is a straight thread and late is npt

Whether it's m10 x 1.00 or 27tpi I'll leave the others to comment

Steve 🤐

A ham fisted 17 year old can make either fit... and did. The old adage : "No need to worry about a taper if you use either brute force or tape..."

[urbantangleweed]

I've Y-1, Y-2 and Y-3 heads, the internal threads all appear to be parallel but trying them with a thread gauge, both 1.0 and 0.9 pitch seem to fit.

M10 x 1.0 makes sense to me. I'll try and pick up some brake pipe fittings as they're available in M10 x 1.0 and see if they screw in......

[mannanan]

There was a very good thread on here about 6 months back from crogthomas. Explains pretty much everything about temperature gauges type.

[midlifecrisisrd]

Regardless of how they measure a Y3 head had the tapered sensor

The straight sensor won't go in

Steve

[lcmarky]

This brings back memories!

I'll have to check my own thread (excuse the pun!)..

[lcmarky]

This might just confuse matters: rdlccrazy.proboards.com/thread/57559/350-400-hybrid-slow-burner?page=10

[urbantangleweed]

Jan 19, 2024 10:16:22 GMT 1 lcmarky said:

This might just confuse matters: rdlccrazy.proboards.com/thread/57559/350-400-hybrid-slow-burner?page=10

Yeah, but then again, they say knowledge is power! 

Thing is, KOSO have temp sensors available in 10x1, 10x1.25 and PT 1/8x28, oh, and they do two ratings, 250°C and 150°C......

www.kosoeurope.com/en/products/accessories/temperature-measuring/temperature-sensors/

I'm guessing "PT" is Parallel Thread, they don't seem to have any taper type threads.

[midlifecrisisrd]

If you Google it PT is pipe thead which is tapered

Steve

[midlifecrisisrd]

I'm sure the Koso one I have is m10 x 1

150 will be water, 250 is oil

Steve

[urbantangleweed]

Jan 19, 2024 11:30:21 GMT 1 midlifecrisisrd said:

If you Google it PT is pipe thead which is tapered

Steve

Makes sense that, cheers Steve.

[urbantangleweed]

Jan 19, 2024 11:31:10 GMT 1 midlifecrisisrd said:

I'm sure the Koso one I have is m10 x 1

150 will be water, 250 is oil

Steve

Makes sense too. The oil ones seem to be anodised red.

[urbantangleweed]

On the way back from the office I stopped off at a motor factors and picked up a couple of M10x1 brake pipe fittings for research purposes. These of course are parallel thread. Putting them into the heads I've got, it seems the Y-1 is standard M10x1 as it screws all the way home. Regarding heads marked Y-2 and Y-3, these appear to be a taper thread as the fitting only screws in for the first couple of threads. Of course, the threads in those heads might be past their best, but I'd go with taper.

[crogthomas]

Good work there.
For what it's worth, every Y1 head I've seen has been M10 and every Y3 has been 1/8NPT.
The Y2's have been inconsistent. I have a Y2 head that has a M10 thread. Of course it's 40 years old and has been through the hands of many bodgers before the current one (me), so who knows what it was originally.
The Y number appears to be an indicator of the compression ratio, but I suppose it's possible that since it is a cast-in number the heads could have been all machined differently depending on their end use and the number doesn't actually mean much at all.
What we do know is that the thread should match the model the head came from. LC2/F/N bikes had a M10 sensor with a blade terminal. The F2/N2/R then changed to a 1/8NPT taper sensor with a bullet connector. Since the wiring loom connectors are different, they can't be confused (not accidentally anyway).

[midlifecrisisrd]

I'll agree Y2 heads are a bit funny

You would expect Y1 to be on early bikes and Y2 on later but I've had very early 1983 bikes (within first 1000) that had no signs of being opened up that had a Y2 head yet I've had mid 83 bikes on Y1

Both had straight threads with a spade sensor

I had it in my head that the Y3 was more 2ua/4ce which would make the Y2 the same across 31k and 1ua but with a thread change

Why we didn't get the 1ua head I don't know

Steve

[urbantangleweed]

Could Y1, 2 and 3 simply be a casting mark referencing the mould cavity each was cast in? The temp sensor thread could be cut either as M10x1 or 1/8 NPT at the threading station on them all?

[midlifecrisisrd]

I think that is a fair assumption

Just Y3 was later and 1ua was the scarlet pimpernel 😂

Steve

[urbantangleweed]

That darn elusive pimpernel! 😊

[urbantangleweed]

Well, whatever thread was in the Y-2 head, it's M10x1 now! 🙂



.....NPT sender still fits too and tightens as it tightens as it should.

[crogthomas]

If you want to preserve the M10 thread I'd avoid putting the NPT sensor in there.
27 TPI is about 0.94mm pitch, so whilst very close to 1mm, is enough for the relatively hard brass sensor to distort the thread in the soft aluminium.

[urbantangleweed]

Jan 29, 2024 12:05:00 GMT 1 crogthomas said:

If you want to preserve the M10 thread I'd avoid putting the NPT sensor in there.
27 TPI is about 0.94mm pitch, so whilst very close to 1mm, is enough for the relatively hard brass sensor to distort the thread in the soft aluminium.

Useful advice, thank you.