The problem with these is that the shaft &/or the bushings wear & cause an exhaust leak that can be quite loud, & be the source of some embarrasment at times.
A common fix was to remove the whole thing & plug the holes as there seems to be no repair kit available, which is a shame.

what does it look like from the inside with the carby off????

we got a few of these... they suck to the highest extent (when not working) on a standard engine.

from memory after taking the inlet manifold off and looking down the is essentially some bars which look like i guess jail cell bars running across...

not sure why your asking abou these but people tend to get rid of these manifolds in favour of ones without, it is a method of heating the inlet manifold to more quickly bring the negine up to temprature in cold environments

there is no air passages between the two or other flow other than heat itself... just essentialy metal and open air for transferring heat, but the removal of any major part or small components from this system will not affect the way the engine runs at all (other than potentially slower warm up in icy conditions)

so welding it in place will not affect it in any way making it run better soz as i said b4 i am a chick lol if i find sum info about this b4 my boyfriend comes back i will feel much better

Removing it intirerly and welding up/pluging the holes would be beter then welding it in place..

Inside it is a big flap... you can weld it in the open position, but like connor says, remove it and plug the holes

The downside is in winter, first minutes of running the engine won't work too good. It really helps the carburetor when the temp is lower.

he got told that if you weld it shut so nothing can get though makes it go faster more killawatt

If you weld the flap in the shut position, the engine will barely run.

If you weld the flap in the open position, it will run the same as a properly working flap, except when cold it runs worse.