cleaning threads on exhaust port.

[cub1961]

the exhaust pipe on my 106 blew out the other day and looks as though the threads on the pipe are worn off. i have another pipe with perfect threads and want to use it. some the threads on the motor look okay but some are flattened and could really use a chasing. i am pretty sure this is 1.25” npt. anyone have any idea where i could get a chaser that size? harbor freight looks like it stops at 1”. th ones i find online look like all metric

 

[kphill]

Its a pipe thread.. Maybe a local plumber can help you out if you take it to him.. They usually have pipe threaders and taps on hand..

 

[mgwin]

You may want to check again. I am almost positive a 1 1/2" NPT tap will work for a 7,10,12, and 14 hp Kohler. At least the OEM 90 degree elbow fits all of them.
I am sitting her looking at my pipe tap now.
Here is the info on the tap. (This may help you in looking online for it.)

GREENFIELD
EM-SS
1-11 1/2 NPT (maybe the 11 is threads per inch)
HSS-E
JAPAN V7

 

[jkoenig]

I thinnk they are 1" pipe threads. Isn't it 1" pipe that fits into them?

 

[etopel]

GREENFIELD
EM-SS
1-11 1/2 NPT (maybe the 11 is threads per inch)
HSS-E
JAPAN V7

It's 1" pipe, 11 1/2 threads per inch (standard NPT)

 

[jkoenig]

Thanks for clearing that up Ed.

 

[charles germer]

remember it's national NOT british latter has a extra thread

 

[cub1961]

You may want to check again. I am almost positive a 1 1/2" NPT tap will work for a 7,10,12, and 14 hp Kohler. At least the OEM 90 degree elbow fits all of them.
I am sitting her looking at my pipe tap now.
Here is the info on the tap. (This may help you in looking online for it.)

GREENFIELD
EM-SS
1-11 1/2 NPT (maybe the 11 is threads per inch)
HSS-E
JAPAN V7

thanks for the info. i said 1.25 because that’s what it looks like it measures diagonally across the threads but from what i have since read online is that npt size is not physical size. before i spend 45 bucks on one of these can you double check that number? i really appreciate it.

 

[mgwin]

Thanks Ed!
That's what I get for posting late in the day! No fun getting old.

Roger,
The info on the tap is correct. Checked it again to be absolutely sure.
If you lived nearby, you could borrow mine.

 

[cub1961]

thanks guys. ya i will probably use it once or three times and it will join the rest of my tools of that category. lol

 

[kphill]

FYI - A regular tap my not have enough clearance to work... They are good for thru holes but they have a tapered point on the end that my not let you get in far enough.. For this you need a bottom end tap ,some call them a bottoming taps that have less taper and a flat nose and can cut farther in the hole.. They are more expensive than a regular tap.. Maybe check with others that have tried this
before you buy a tap..

 

[mgwin]

Kevin,
Pipe taps usually have a flat end.

Roger,
Only three times? Don't bet on it.
I will bet you will use it that much in one year. You know yellow and white fever lasts a long time!

 

[kphill]

Marty, all taps have a flat end.. That is a regular tap you are holding.. A bottoming tap looks much different...

 

[mgwin]

Not all of them! The previous pic is a 1" pipe tap.
Here is a pic of some "regular" taps that I have. No flat ends here.

 

[cub1961]

and when i do this what oil should i use?

 

[mgwin]

You can buy some tapping oil like "Rapid Tap," but I just used a little PB Blaster. When tapping a hole or refurbing threads, I always run the tap in about 1/8 to 1/4 turn. Then back it out just a little more than that. Then go back in about that much more. It really depends on what size tap. The smaller the tap, the greater a chance of breaking it off in the hole.

 

[kphill]

Those are thru hole taps Marty.. of course those won't work.. As for oil you can use tap oil, Marvel Mystery Oil, Or and light cutting oil works well...

 

[ffgosda]

Pipe taps are tapered so I don’t think there is a bottoming tap for pipe like there is for straight threads. The measurement for pipe taps is the inside diameter of the pipe. 1” I.D. pipe tap is probably close to 1 1/4” O.D.. The Harbor Freight 1” pipe tap with 11 1/2 tpi is probably what you need. Bottoming taps are usually for straight threads such as bolts in castings with blind holes.

 

[mfrade]

The measure of pipe is by the Inside Diameter of the PIPE.

 

[eweiss]

A short piece of pipe with a cut from a cut off wheel will also clean threads, the cut need to be angled from top to bottom.