Topic: Ham-fisted shade tree mechanic needs bolt & tap size

[greenjeans]

'72 CB750K 

My 2 right side pipes had developed small holes along the seams (HM341's) and I took them off
to try and fill them.  Used some sort of muffler repair in a can - actually seems to be working.
Anyway, I picked up some new copper gaskets for the exhausts and when re-installing I put the gaskets in
and then mounted the exhaust to the head and tightened down....screws almost seemed cross-threaded
so I want to chase the threads and put new screws in there.   

Anybody know what size those screws are ?

And, aren't ALL the exhaust flanges identical ? (In theory)  I can't get the number 4 pipe to fit all the way
onto the flange, BUT, they don't seem to slide on far enough (specifically the number 4 pipe) there is almost 1/8"
of an inch left that it could slide onto the flange.



I've tried taking it off and inserting the flange into the pipe...same result - doesn't slide far enough on there to
cover the slits on the header pipe.  I have cleaned everything, so there's not any rust/debris keeping me from sliding them on further. 

Are the flanges numbered ?
Am i going to have to take everything apart again ?  Hate have to wait for new exhast gaskets again

[fuzzybutt]

i believe theyre 8x1.25mm

[CBGhia]

Does the flange have to sit flush?   As long as the gasket is compressed and there is no leak, shouldn't it be fine if it sits out just a bit? 

And dude is you are ham fisted,  I have no idea what I am, because you have done some great work on the bikes I got from you.

[fuzzybutt]

if the holes are too thrashed try this................. when i was heavy into air cooled vw's a commin problem on a car with the original exhaust was the exhast stud snapping off when trying to remove the exhaust. if the hole got buggered up there was something called a "step stud" larger diameter to screw into a newly enlarged and re-tapped hole in the head and the standard size on the other end. i THINK vw heads and sohc 750's use the same diameter/thread count studs. might be a possibility.