A thread about threads...

[johnhb67]

Hi, I ordered a new 14mm thread water temperature sensor for my Bukh. When I screwed it in, it would not tighten. So I had the wrong thread.. looking again I see another sensor 14mm x1.5 - is this the correct thread for the Bukh?
thanks

see screen shot attached....

 

[penberth3]

Hi, I ordered a new 14mm thread water temperature sensor for my Bukh. When I screwed it in, it would not tighten. So I had the wrong thread.. looking again I see another sensor 14mm x1.5 - is this the correct thread for the Bukh?
thanks

see screen shot attached....

You've got the engine. Measure the thread and find out.

 

[vyv_cox]

M14 can have thread pitches of 1, 1.25 and 1.5 mm. 1.5 mm is the standard ISO pitch but Bukh may have used any of them. Can you not measure the old fitting?

 

[rotrax]

Try a 14mm spark plug in the thread. That is 14 x 1.25 and will confirm or eliminate one size.

 

[billskip]

When I screwed it in, it would not tighten.

Sounds like the female is stripped/damage.

 

[penberth3]

Sounds like the female is stripped/damage.

Ah yes, possibly. I took it to mean the fitting wouldn't screw right down, e.g. the wrong thread jammed after a turn or two.

 

[LittleSister]

According to this old thread, it appears to be listed as a standard M14 thread.

Thread 'Reluctant to buy a third bukh temp sensor'

14 May 2023

After clocking my temp gauge yesterday at over a 100deg, panic set in. Down below checking the engine caused me to come down with the worst seasickness ever. It turned out the engine was not even hot to touch, and the sensor is now shorting to earth causing a false reading. They only seem to last about 18 months I've noticed.

• Rhylsailer99
• Replies: 13
• Forum: Practical Boat Owner's Reader to Reader

 

[penberth3]

According to this old thread, it appears to be listed as a standard M14 thread.

Thread 'Reluctant to buy a third bukh temp sensor'

14 May 2023

After clocking my temp gauge yesterday at over a 100deg, panic set in. Down below checking the engine caused me to come down with the worst seasickness ever. It turned out the engine was not even hot to touch, and the sensor is now shorting to earth causing a false reading. They only seem to last about 18 months I've noticed.

• Rhylsailer99
• Replies: 13
• Forum: Practical Boat Owner's Reader to Reader

Er, refer to Post #3, there's a choice of three standard threads.

 

[ducked]

M14 can have thread pitches of 1, 1.25 and 1.5 mm. 1.5 mm is the standard ISO pitch but Bukh may have used any of them. Can you not measure the old fitting?

Measuring the thread pitch on an internal thread is non-trivial, or at least I find it so.

Faced with a similar problem obtaining a flywheel extractor for a SYM Wolf (Honda CB125 semi-clone) motorcycle recently (Allegedly unobtanium in Taiwan and no longer obtainable direct from SYM for the non-fuel injected model. Motorcycle shop I went to rather pathetically claimed not to have one and thus to be unable to do the job) and having ordered one online while in the UK that didn't fit, I eventually went to a bolt emporium in Kaohsiung and just bought as comprehensive a selection as I could find, from which, with a bit of precision hacksawing and some plastic bag polythene, I made one which worked OK.

Wee Woodruffian Thing In My Oil Strainer

Failing that I could probably have used the bolts as gauges and then ordered an extractor (or in your case a sensor) with the same threads.

Bolts are quite cheap.

 

[vyv_cox]

Measuring the thread pitch on an internal thread is non-trivial, or at least I find it so.

But presumably he still has the old fitting with an external thread?

 

[Moodysailor]

Depending on the age of the engine, it could be an imperial thread not metric. Check with a Bukh agent.

 

[ducked]

But presumably he still has the old fitting with an external thread?

Right enough (I realised after posting but it didnt seem worth an edit) though he might have lost it. Sort of thing I would do

In the case of my flywheel example there wasn't one.

 

[Bouba]

Measuring the thread pitch on an internal thread is non-trivial, or at least I find it so.

Faced with a similar problem obtaining a flywheel extractor for a SYM Wolf (Honda CB125 semi-clone) motorcycle recently (Allegedly unobtanium in Taiwan and no longer obtainable direct from SYM for the non-fuel injected model. Motorcycle shop I went to rather pathetically claimed not to have one and thus to be unable to do the job) and having ordered one online while in the UK that didn't fit, I eventually went to a bolt emporium in Kaohsiung and just bought as comprehensive a selection as I could find, from which, with a bit of precision hacksawing and some plastic bag polythene, I made one which worked OK.

Wee Woodruffian Thing In My Oil Strainer

Failing that I could probably have used the bolts as gauges and then ordered an extractor (or in your case a sensor) with the same threads.

Bolts are quite cheap.

Before this amazing internet age...most things in the world were made of unobtainium....

 

[penberth3]

Measuring the thread pitch on an internal thread is non-trivial, or at least I find it so.....

Thread gauges are useful things to have, but I can think of three improvised methods for measuring an internal thread. It really isn't difficult.

 

[ducked]

Before this amazing internet age...most things in the world were made of unobtainium....

Many things of this nature still are in Taiwan, ironic since many of the tools are either made here on in neighbouring China.

Antiseize, for example, was actually unobtainable in sub-500g quantities (which would last me until the heat death of the Universe) when I got here. I'm told the internyet has fixed this fairly recently, but in practice you need Chinese, and in any case I evolved effective substitutes and eventually bought some for critical applications in Japan.

AFAIK brake grease (which I bought in several varieties in Japan and Australia) is still unobtainable here.

Its probably due to a mixture of interacting factors such as no DIY, cuturally driven rapid obsolescence (as for the above bike which is an old but formerly very common model), general cluelessness among the punter population, and the pros not being very pro.

 

[ducked]

Thread gauges are useful things to have, but I can think of three improvised methods for measuring an internal thread. It really isn't difficult.

Do tell.

Or are you "Penberth 3, International Man of The Three Mysterees?"

I tried taking an impression with RTV on a stick, which sort-of worked, just not quite well enough.

In the end buying the bolt selection was cheap, simple and effective.

 

[LittleSister]

Er, refer to Post #3, there's a choice of three standard threads.

I know. I was pointing out that the listings for the part used was simply 'M14', with no suffix, implying, as I understand it, to the standard (coarse) M14 and not one of the finer versions.

 

[rogerthebodger]

Do tell.

Or are you "Penberth 3, International Man of The Three Mysterees?"

I tried taking an impression with RTV on a stick, which sort-of worked, just not quite well enough.

In the end buying the bolt selection was cheap, simple and effective.

https://www.amazon.co.uk/Thread-Cut...59237214&s=industrial&sr=1-6&ts_id=6286355031

Many suppliers including amazon

 

[ducked]

Screw Thread Pitch Cutting Gauge Tool, 1 Piece Metric & Imperial & US Screw Gauge, Stainless Steel Screw Thread Gauge Tool, 60°/55° Metric and Imperial Thread Pitch Cutting Gauge : Amazon.co.uk: Business, Industry & Science

Many suppliers including amazon

So, that'd cost me about 20 quid with shipping, take a few weeks to arrive, MIGHT work in my hands (never used one) in the rather awkward rather deeply recessed location, and if it did then I'd STILL have had to find, order, and have delivered an extractor of the (hopefully correctly) measured thread pitch, or buy the (hopefully correctly) measured thread pitch bolts anyway.

As opposed to just buying some bolts

Uum...