broken bolt in t-stat 1990 225 yamaha

[MID FL CAP]

Hello,I removed the thermastat,and broke 3 out of four bolts in the process.I was able to heat 2 of them up and the were removed with a great deal of power.The third one would not move ,so I cut it off and drilled it out with a small drill bit,BUT I went to far and went thru the block,I think.The question is ,did I really do a lot off damage by goning to far with the drill dit?Is there a water jacket behind that ,or what,I do'nt know for sure? Could I put a little J B weld in it and then the bolt,with some anti-seize on it then the gasket and call it good,or a nother course of action reqired? Hope some small fix-it or major job? At any rate the t-stats were shot,so I was doing something right by inspecting them before heading for blue water!! THANK YOU for your help in advance!!!Ray.

 

[MID FL CAP]

Re: broken bolt in t-stat 1990 225 yamaha

Note To Self And Others.i Used Heavy Force With Vise Gripes,was Able To Take Two Out That Way,with Help From Penertrating Oil.the Other One's: I Hade To Use Heat (a Cutting Tourch) It Helped Alot. The Last One Could Not Get It To Move No Matter What,cut It Off,and Drilled It Out And Then Re-taped It.put All New Bolts Back In It With Some Pipe Dope,new T-stats ,gaskets,everything Working Fine.

 

[mcbassin]

Re: broken bolt in t-stat 1990 225 yamaha

You might also note great care should be taken when heating that aluminum, it is very easy to get it too hot fast then things can go bad in a hurry.

 

[rodbolt]

Re: broken bolt in t-stat 1990 225 yamaha

gotta love heat
at 6ft and and amazing 140 pounds I am a special scarecrow, I aint scared of fire.
lots of old saltwater yammies here with 1/4X20 bolts holding the t-stst housing in place though.
but if your careful you can use that cutting tourch to heat it enough the bolt draws the threads right out making a helicoil a snap to install.