exhaust cover bolt broken

[brazil33]

Heres my dilemma,..I pulled the exhaust covers off my C85 Yamaha outboard and broke a bolt, #7, 2nd from the bottom, lower left outermost bolt,...drilled, tried a fluted ez out extractor and snapped that off . It broke just above the surface, a sharp protrusion remains - but looks like very little to grab onto and try anything further. So,..given this unfortunate situation and not wanting to pull it all apart,or damage it further...am I guaranteed and exhaust leak if I just plug the hole with something - sealant, JB weld? and install new bolts and gaskets in the remaining 17 holes? Anyone?

 

[kend301]

Re: exhaust cover bolt broken

Unless someone posts a miracle fix , you need to try to get the ezout out of the bolt , do not try to drill the ezout as it will kill alot of time as well as tighten it up . If you have a "shoulder" to work with and small vice grips do not work , Take a very sharp small chisel and small hammer start working the ezout ... I have also had a center punch work if you can get a good enough bite on it . tap it with the chisel / punch at a 45 degree angle . If you do get it out , drill the bolt out to the point you can use a tap or get a helicoil kit to restore the threads ..
REMEMBER ... an ez out "bites" with left handed threads , to get the ezout to come out you must go clockwise (same direction you would tightening a bolt ) when working it out !!!

 

[ENSIGN]

Re: exhaust cover bolt broken

Been down that road before!!! My suggestion is to NOT try to remove the EZ out you're going to do more damage to the aluminum than what it's worth.clean her up and use a good sealer.

 

[brazil33]

Re: exhaust cover bolt broken

Thanks, it is a tapered extractor - no threads, so what strategy would you suggest? Should I still try to get it to turn? I was going to try a dremel with diamond point, but it is in a good 1/2" at least. I have maybe 1/16" on either side of what's left of the bolt.

Sealing it up also seems the best bet, ...lol...0 for 2 so far,...any particular product to use?

 

[ENSIGN]

Re: exhaust cover bolt broken

Stop trying to get anything else out,grind the ez-out and whatever bolt remaining flush with the engine housing.clean everything up including the bolts,you can use permatex #2,mercury perfect seal or hi-temp sealer. I would recommend using neverseeze on all the bolts.Good luck,Ted

 

[99yam40]

Re: exhaust cover bolt broken

make sure the neverseize does not contain copper or it will react with the aluminum.

 

[rodbolt]

Re: exhaust cover bolt broken

and now everyone knows NEVER EVER try to easy out small corroded in fasteners.
the taper WILL expand the fastener and lock it in even tighter.
weld a nut to the broken extractor and remove it.
then use the correct tap drill and drill and tap the hole,use a heli coil if nessasary and complete the repair.
if the cover leaks internally its quite possible to junk the engine due to water intrusion into an ex port.
your choice.

 

[ENSIGN]

Re: exhaust cover bolt broken

You've got nothing to lose,go for it,good luck,Ted