[suede55bowtie]

I searched on here and google and found about 76,000 answers on what the exact thread count, size, and pitch is for a '63-'70 Triumph 650 sludge trap. Mine is kind of boogered up and am looking to order a tap set to redo it. I talked to a local Triumph guy, he basically told me I'll definitely have to order it from England. If I can't get this guy retapped I'ma have to find a new crank, any help?

 

[BGP]

I got a new hex socket plug for mine and it didn't fit. I figured my threads were messed up until the old one went in like a boss. Turns out the new plug threads weren't deep enough and it would bind right away. I smeared valve lapping compound on there and did the back and forth thing for about two beer. After that and a good cleaning, it's right where it should be. Maybe that could work for you too...

 

[Mr.Pete]

The plug is 7/8" diameter on a 650 and 20 tpi.It will be a 60 degree thread,but I think it's BSC (cycle-thread),not a Unified thread ;although there's not a big difference.

7/8"x 20 tpi UNEF (Unified extra-fine aircraft thread) would be close enough.

 

[mitchsfab]

check this place

Reiff & Nestor Company

Quality Taps Since 1912

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7/8-20 Tap

Tap Size:
PD/H Limit:
Flutes:
Chamfer:
Series Designation:

EDP No.:

How do I buy R&N Taps?

EDP	Product Name	Tap Size	Series	PD/H Limit	Flutes	Chamfer
84057	National Extra Fine Pitch (NEF) Hand Taps	7/8-20		H-5	6	Taper
84058	National Extra Fine Pitch (NEF) Hand Taps	7/8-20		H-5	6	Plug
83059	National Extra Fine Pitch (NEF) Hand Taps	7/8-20		H-3	6	Bottom
84059	National Extra Fine Pitch (NEF) Hand Taps	7/8-20		H-5	6	Bottom
83058	National Extra Fine Pitch (NEF) Hand Taps	7/8-20		H-3	6	Plug
83057	National Extra Fine Pitch (NEF) Hand Taps	7/8-20		H-3	6	Taper

 

[thecj3man]

The plug is 7/8" diameter on a 650 and 20 tpi.It will be a 60 degree thread,but I think it's BSC (cycle-thread),not a Unified thread ;although there's not a big difference.

7/8"x 20 tpi UNEF (Unified extra-fine aircraft thread) would be close enough.

I boogered up the threads in my crank with a new hex plug. I ordered a 7/8 NEF tap from mcmaster-carr and it worked like a charm to clean the threads up.