Starter bolt

[tech62571]

I have a 3.0 mercruiser and the bolt for the starter broke off.. About half the bolt is still in the block.. anyone know a trick to get under there and get the piece of bolt out? It's underneath .

[mmwjr]

Have you tried a broken bolt extractor? First spray some PB Blaster to break any rust.

[tech62571]

I would but the bolt screws up into the block from the bottom. Poor engineering . Trying not to pull the motor over a bolt

[tech62571]

Any reason I couldn't drill it straight through and use a nut and bolt?

[mmwjr]

Originally Posted by tech62571

I would but the bolt screws up into the block from the bottom. Poor engineering . Trying not to pull the motor over a bolt

So it broke flush? Remember these started as car engines not designed for boats as a primary thought.

[mmwjr]

Originally Posted by tech62571

Any reason I couldn't drill it straight through and use a nut and bolt?

I guess this may be possible as long as you don’t damage the block drilling it out and that the opposing side is flat that the bolt/nut can provide even pressure across. I would first consider taking the boat to a local machine shop to see if they can remove it.

[tech62571]

I talked to a boat guy and he said .. gotta pull the engine mounts.. and jack up the motor.. to drill it to pull it out.

[mmwjr]

Originally Posted by tech62571

I talked to a boat guy and he said .. gotta pull the engine mounts.. and jack up the motor.. to drill it to pull it out.

Good luck.

[tech62571]

For anyone that has this issue.. I used a angle grinder and shaved about a 1/4 inch off and the bolt was exposed. Took a very long 3/8 drill bit and drilled out the broken bolts . Then got 5in bolts and nuts and bolted them in . Came out great.

[mmwjr]

Originally Posted by tech62571

For anyone that has this issue.. I used a angle grinder and shaved about a 1/4 inch off and the bolt was exposed. Took a very long 3/8 drill bit and drilled out the broken bolts . Then got 5in bolts and nuts and bolted them in . Came out great.

So you removed 1/4” off the top of the block where the bolts screw in? How much metal is left? There’s a lot of torque transferred into the block when the starter engages, hopefully it can handle it over time without any stress cracking.

[tech62571]

It's actually more metal then the other bolt has. The bolts don't go all the in . When I grinded it.. there was about an inch from the top of the bolt to the top of hole.

I'm completely sure there's no structural issues. And it beats pulling the motor. If they ever break again.. it's a quick fix . When I googled this issue.. all I see is.. yet another set of starter bolts broken.

[mmwjr]

Hopefully you’re right.

Typically when I’ve seen broken starter bolts it’s because many aftermarket starters come with bolts that are too long and bottom out before fully seating against the starter.