Looks like a chunk is ready to fall off there,bummer.I have had a case welded so sure that could be repaired also and retapped. If your on a shoestring budget some JB Weld would probably work also as that is a low stress area just holding that small cover on. Know you probably want to keep your engine original but a replacement cover may be as cheap as a weld up,lots of those out there. I have some extras and here is one for example http://www.ebay.com/itm/HONDA-CB750-SOHC-VALVE-COVER-69-78-/290693379211?pt=Motorcycles_Parts_Accessories&hash=item43aeacf48b&vxp=mtr
Thank you for your advice.. damn, $20 is dirt cheap.. I was expecting something like 500. Got a friend who is going to try welding it, if that goes to sh**, I'll just pick up a new one.
By the way... I've read allot of horror stories on blasting engine parts, are there any risks associated of doing this cover?
Does your "friend" have a lot of experience?
It will take a good TIG welding machine and a welder with a lot of experience.
Which welding filler wire?
The answer is 4043. Does your "friend " know that?
On a repair like that it will be best to just forget about that little part that is breaking off and put all new metal in that area.
Then drill and tap.
Each threaded hole can have a selection of 3 hole sizes to drill before tapping. Use the largest of the 3 choices given.
DO NOT tap with a electric drill!!
Do it by hand. Back off the tap every couple of turns.
It has to be spotlessly CLEAN shiny metal before welding. Use a stainless steel tooth brush.
Take it to a place that welds aluminum cylinder heads.
Most machine shops can tell you where to take it to.
Do not risk ruining a good cylinder head cover.
BTW...Just throwing a cylinder head cover away because it needs one little repair is a real shame.
At least do NOT throw a part like that in the garbage. Give it to another forum member or take it to the scrap yard,but do not put in in the garbage where it will be used for land fill. It is a valuable vintage part.
