Dear lost,
Trying to understand what you are saying has me just as lost as you are.
You know what you have done we have nothing more than the words you posted which quite frankly make no sense .
So please try to explain yourself more clearly, think of us as deaf dumb & blind.
If you do not know the name of a part , look up your mower on one of the parts retailers web site, like Jacks Small Engines or Partstree.
Listing them by name and part number is a big help
If we can not understand what you are saying it will be very hard to offer any meaningful help.
For a muffler to glow red one r more of the following needs to be happening.
1) engine running too rich, but not rich enough to 8 stroke
2) spark to be happening too late so fuel is still burning when the exhaust valve opens
3) exhaust valve opening too early ( before all the fuel has burned )
4) exhaust valve not sealing 100 % so some of the burning fuel passes into the exhaust
5) engine not firing every time so unburned fuel is burning inside the muffler.
IT is quite common for an inch or so of the headder pipe nearest the head to glow red hot as the gasses coming out are very hot.
