meadowfield 2,545 #1 Posted April 1, 2012 Apologies for bringing this up again - theres a million posts and I've read half of them ! My GT14 exhaust has bit the dust... The general gist is the the pipe thread is 1" NPT - but the dimensions are different. 1 1/4" outside diameter 1 1/8" inside diameter - unless mine as lost an 1/8" through corrosion ! Am I going mad? surely all Kohler K series are 1" NPT and I just need to buy standard fittings??? thanks mark (loving the sound of a K321 with no exhaust under load - it sounds awesome, but not sure if the neighbours are ) Share this post Link to post Share on other sites
Martin 2,130 #2 Posted April 1, 2012 mark, looks like 1" npt to me. the only k series that could have larger than 1" is the k341 or 16 hp engine. as has been mentioned on here somewhere recently, some (or all)of these were 1 1/4" npt Share this post Link to post Share on other sites
TT-(Moderator) 1,128 #3 Posted April 1, 2012 Unless it's a K-341 or an M16 Magnum, the exhaust port is 1" NPT Share this post Link to post Share on other sites
pfrederi 17,147 #4 Posted April 1, 2012 NPT sizes are nominal. The actual measurement size varies from the stated size. If you are interested go here for a explanation http://www.mcmaster....on-pipe/=gx544k Share this post Link to post Share on other sites
meadowfield 2,545 #5 Posted April 1, 2012 Thanks guys, it's a GT14 with original k321 engine. I'm just double checking things here as I though 1" NPR would be 1" internal diameter, that's what is throwing me. Can anyone measure and see if they are seeing the same? Thanks Share this post Link to post Share on other sites
Martin 2,130 #6 Posted April 1, 2012 well i just measured a few of them and they are all 1.04" to 1.05" . fairly close to 1 1/16".... i guess it all depends on the wall thickness. a better indication would be the od..... they are about 1.3" or just over 1 1/4" Share this post Link to post Share on other sites
Pollack Pete 2,273 #7 Posted April 1, 2012 I'm a union pipefitter.Like everyone stated,that's 1 inch NPT.The OD measurement of all steel pipe of any given size is the same.When you get into the different wall thickness,it's different schedule pipe.Sch 40 is thin wall.SCH 80 is heavier wall.SCH 160 is heavier yet.OD stays the same so it fits all 1 inch steel or iron fittings,whether threaded or welded.Hope I made myself kinda clear. Share this post Link to post Share on other sites
meadowfield 2,545 #8 Posted April 2, 2012 cool ! was just checking... I'll try find a 1" nipple thanks Share this post Link to post Share on other sites
