EGT Weld on nut.

[Fat Trucker]

Morning all,is the nut you weld on to the exhaust a universal one? Can't afford to buy a gauge yet but I'd like to weld the nut on over the winter(and block it off). Also what size hole do I need to drill into the exhaust please?
cheers for any help.
ove

[mainstand]

off the top of my head its 17mm mate. but i could be wrong it was a while back now since i fitted mine.. you only need a hole the diameter of the sensor which i'd wait for if you dont have it. Just weld the nut on then when you have the sensor it takes seconds to drill the hole.

[coaster]

Beware, it is a fine thread, not the normal pitch. Drill the hole the same size as the hole in the nut, you don't want it too tight in case the nut isn't quite centred over the hole. I just did one on an Avanti Super Tourer last weekend, normally I would advize welding onto the back of the pipe to keep the probe out of harms way. That was fine on my JL3 but would have got in the way of the mounting springs on the Avanti so had to move it to the side.

[martyn dwane]

i believe the thread is 1/8 NPT. i use a Long cylinder head nut, drill it out 8.5mm or 11/32" then run tap thru it.

[MickYork]

As i recall it's a "strange" thread. The nut/bolt actually have a small taper which allows the thread to tighten and in theory give an air tight seal. The 1/8 NPT as mentioned may be correct.

[coaster]

When I did the JL3 I managed to find a nut in my 'nut collection' gathered over decades of car/scooter fettling, no idea what
The tread was or where it came from but it was most likely imperial. I couldn't find anything suitable last weekend when doing the Avanti but found the the nut that holds the probe in place is perfect. Luckily I has a spare one from a duff probe and although it is stainless was easy to weld on with normal mig wire.

[martyn dwane]

if any one wants a nut done, send me a pm.

[Fat Trucker]

Cheers for all replies. I'll wait till I can afford the whole kit before I get nut welded on.
Ove.