Evinrude 9.9hp - broken bolt on thermostat cover

[Kiwi]

I recently bought an Evinrude 9.9hp very original little engine runs ok but needs the thermostat replaced, This morning while taking off the cover to get at the thermostat one of the bolts has broken off in the block. What would you suggest I do to get the remains of the bolt out ? Never had this happen before so unsure how to proceed. Looks like the cover has never been off.

Thanks
Mike

 

[kbait]

I think both versions of thermo locations over the years have thermo covers that bolt to the cylinder head. Pull the head off for easier extraction, or bring to a machine shop where they extract broken bolts all the time..
Good luck!

 

[rothfm]

Like other poster indicated, you can bring it to a shop and be done with it. If you are handy and so inclined it can be done. Theres alot of tips, tricks, and techniques to get this done. Search on Youtube and you will see. Depends on what equipment you have(if welding a nut on it) and skill level.

I just finished removing remains of a Thermo cover bolt on my 140. I center punched the stud very carefully to be sure I got a depression in the center. Then (using all Cobolt bits) 1st drilled it with 1/8 to exact dept of the old bolt carefully and straight. Then progressively used larger and larger bits (5 in total), to remove material until threads "just start" to show. Then I use a pic and tools to remove the old threads. Sometimes using a tap back n forth to clear the debris and threads.

The hole took the new bolt nicely and tightly. Takes awhile but if patient, can be rewarding.

OR.....Take it to a shop. LOL.

 

[rothfm]

Oh, when doing the above...NEVER use an easy-out. Hate, hate, hate them. If it breaks off, and they certainly will, you are really stuck. Not worth the chance.

 

[boobie]

Left handed drill bits also work real good for this operation.

 

[Kiwi]

Ok thanks for the replies. Taking it to a machine shop tomorrow. Its a great little motor in wonderful condition so I'm going to let the experts deal with it,