# Resectioning a threaded rod



## cathead (Nov 4, 2020)

Up before the birds, I headed for the shop with a cup of coffee.  One of my shop projects is to fix up a scrap yard
GX390 13 horse engine.  So far it has spark and nice compression so I ordered a muffler, an air filter and a starter solenoid
and got those parts installed.  The air filter threaded rod broke off at the top so lost about 1/2 inch of metric threads so too short now
to hold the air filter housing on.  I sawed the bolt in half and threaded the ends in 1/4x20 and made a threaded piece out of 5/16 rod to extend 
the bolt using a collet in the lathe to drill and tap.   The bolt must be molded into the mount bracket as I could see no way to replace it, thus
the repair.  It was not much of a project but needed to be done to have a functional air filter system.  Also, the air filter housing(plastic material)
had a big hole punched in it so used a propane torch to soften and reform the plastic and close up the hole.  It's all back together now
and about ready to test run.  I have a vertical band saw that would love to have this engine powering it.  The electric start and extra horsepower
will make for a better sawmill set up.  
	

		
			
		

		
	



I added some brass to ensure that the resectioned part would not unthread.  It's not beautiful but will seldom be seen inside the air filter.
	

		
			
		

		
	



The blemish on the plastic is where the big hole was.  It sealed up nicely and I was very pleased with the result.  The only thing left to do
might be to clean the carburetor.  It was amazingly clean in the float bowl so will try it as is and see if it will run.


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## Al 1 (Nov 4, 2020)

Get it done.   Nice.  Al


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## brino (Nov 4, 2020)

Nice repairs.
Good luck with first start!
-brino


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## Papa Charlie (Nov 4, 2020)

That was very creative. Good luck on the test run.


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## MrWhoopee (Nov 4, 2020)

That hole you closed up was probably for spraying ether. I put one in my old 10 hp B&S/Generac.


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## matthewsx (Nov 4, 2020)

If it has spark, compression and fuel and it still doesn't run pull the flywheel. These engines shear flywheel keys pretty easy....

John


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## cathead (Nov 4, 2020)

MrWhoopee said:


> That hole you closed up was probably for spraying ether. I put one in my old 10 hp B&S/Generac.



That was not the case.  There was a piece of pipe stabbed into the air cleaner when it was tossed off at the scrap yard.
It punctured the air cleaner inside as well.  I rarely use ether unless I am starting an old diesel Caterpillar.  Once I tried
using gasoline on the old D6 and it seemed to work as well as ether.....


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## cathead (Nov 4, 2020)

matthewsx said:


> If it has spark, compression and fuel and it still doesn't run pull the flywheel. These engines shear flywheel keys pretty easy....
> 
> John



I think I saw in some literature on Honda GX390 engines that the flywheel nut is supposed to be torqued to 84 foot pounds.


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## fixit (Nov 5, 2020)

I had a repair shop for small engines for several years. NEVER saw a HONDA with a sheared key. saw plenty on vertical mowers with cheap engines but never on a horizontal Honda. I betting it will start. be sure the valves are adjusted.


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## cathead (Nov 5, 2020)

I can report that the engine runs quite well.  On the first couple of pulls on the rope, it back fired and broke the starter rope
so replaced that and gave it another pull or two.  It smoked up the shop and after a minute or two of running, cleared up 
and ran fine.  I aired out the shop and next will be looking at putting the engine to work at some application.  I have another one ,
more of a parts motor maybe as it is missing the pull starter and air shroud.  I will hang on to that one for parts and
hopefully will find the missing stuff and get that going as well.  For the time being, I will store it in one of my sheds
until some parts come my way.  Y'all have a good day.


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## Papa Charlie (Nov 5, 2020)

Well that turned out to be one heck of a find at the scrap yard. Good for you.


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