Spark plug won't screw in

Rtraveler

Forum Newbie
Joined
Apr 9, 2017
Threads
1
Messages
2
I have a Briggs and Stratton (Serial num: 14 0812 58 94318 ). I was trying to replace the spark plug and I think I crossed the threads because I can't even screw in the old sparkplug. Anyone ever have this problem? Thanks in advance.
 

reynoldston

Lawn Pro
Joined
May 23, 2011
Threads
92
Messages
5,705
You might just try to clean up the head plug hole with a 14MM tap if the damage isn't too bad? They make repair kits for people that cross thread spark plugs if that doesn't work for you.
 

Boobala

Lawn Pro
Joined
Feb 15, 2015
Threads
200
Messages
7,000
You might just try to clean up the head plug hole with a 14MM tap if the damage isn't too bad? They make repair kits for people that cross thread spark plugs if that doesn't work for you.

Many a mechanic has been in that boat.... if the tap doesn't work... the repair kit USUALLY does ( I've used what is
called a Heli-Coil thread restoring kit.... even that requires drilling the plug hole oversize and as straight as possible...
worst case scenario ...replace the head or cylinder ..$$$$

Whenever starting threads ..PATIENCE ... ALWAYS start by fingers (if possible) ... I've seen guys "rip" into assembly of something ... starting a threaded item with a powered tool ( sorta like a NASCAR pit crew ) and it ending up with less than the desired results...
ever watch some guys put "lug-nuts" on a wheel and cross thread them using the "air-gun" if they don't break em off ..wait till next time they have to be removed !!!! ..:mur:
 

Rtraveler

Forum Newbie
Joined
Apr 9, 2017
Threads
1
Messages
2
You might just try to clean up the head plug hole with a 14MM tap if the damage isn't too bad? They make repair kits for people that cross thread spark plugs if that doesn't work for you.

So are all Briggs and Stratton lawnmower sparkplugs 14mm in diameter?

I found a rethreader tool at Home Depot. "GearWrench 14 mm Spark Plug Rethreader "
I'll try this and let you know the results, thank you.
 

ILENGINE

Lawn Pro
Joined
May 6, 2010
Threads
39
Messages
9,867
14 mm 1.25 pitch is what almost all spark plugs in small engines, and outdoor power equipment, and most automobiles that don't take special style plugs. some of the newer trimmers and chainsaw use a 10 mm and ATV's use 10, 12, or 14 mm

The change over from SAE thread to metric threads on spark plugs started back around 1937.
 

Pumper54

Well-Known Member
Joined
Jun 19, 2014
Threads
19
Messages
819
You might think about putting a bit of grease on the tap to catch the cuttings, cut a little, wipe off the grease, add more, cut, repeat as needed. Unless of course you pull the head and do the clean up on the bench. That makes life so much easier.
Tom
 

reynoldston

Lawn Pro
Joined
May 23, 2011
Threads
92
Messages
5,705
You might think about putting a bit of grease on the tap to catch the cuttings, cut a little, wipe off the grease, add more, cut, repeat as needed. Unless of course you pull the head and do the clean up on the bench. That makes life so much easier.
Tom

I use a shop vac and never had a problem yet.
 

motoman

Lawn Addict
Joined
Aug 11, 2011
Threads
65
Messages
2,566
Boobala has it nailed...very important to cut threads "square" to gasket surface. Even if it means removing the head and placing it in a vise or mill table to achieve. Gasket will not seal if not flat to head and spark plug.
 
Top