I have a 2006 model 90hp Yamaha 2-stroke and i recently had it overheat. I removed the head and cleaned it up as it had a lot of salt and deposits built up inside and was disrupting water flow. I cleaned it up and replaced the thermostat and all new head gaskets along with new water pump. I then got the bright idea that i would try tp remove the exhaust cover since the heads went so well to see what kind of deposits were there and maybe 12 of the 18 bolts came right out and the rest were not wanting to move. I decided if I kept messing with it I would just end up breaking a lot of bolts so I decided to tighten the bolts back up and leave it alone. Of course in doing this I found out that I actually broke a bolt and now if I run water through the motor it leaks... So my questions is what is the best way to repair this.
Right now all the bolts except the 1 are on and tight but the 1 broke off flush with the block from what i can tell. the remaining bolt piece is about 3/4" long. I called a few machine shops and either they won't touch it or say they want to remove the cover and weld a nut to the broken bolt. The problem is that of course to remove the cover they'll probably break at least 5 more bolts at least 1 of course will be down low where the only way to repair will be to remove the powerhead to get at it. My question is should I try to drill out the bolt with the cover still on or go about trying to remove the cover? Or try to grind off all the bolt heads and remove the cover that way. Looking for the best/most cost effective way.
I know there is risk drilling it.
Right now all the bolts except the 1 are on and tight but the 1 broke off flush with the block from what i can tell. the remaining bolt piece is about 3/4" long. I called a few machine shops and either they won't touch it or say they want to remove the cover and weld a nut to the broken bolt. The problem is that of course to remove the cover they'll probably break at least 5 more bolts at least 1 of course will be down low where the only way to repair will be to remove the powerhead to get at it. My question is should I try to drill out the bolt with the cover still on or go about trying to remove the cover? Or try to grind off all the bolt heads and remove the cover that way. Looking for the best/most cost effective way.
I know there is risk drilling it.
