Another 3.0l starter bolts broken off question.

[Spreadem]

As referenced off of many archived topics such as 3.0 starter bolts broken off, pull motor? for example, 'I have drilled several starter bolts out of my 3.0 Mercruiser. I use a smaller air drill and a small left handed drill bit, a mirror, flashlight, center punch, and low speed. I have had several catch and unscrew out! Is this a common problem? What do I do to keep it from breaking bolts??

 

[Fun Times]

Hi there Spreadem , welcome to iboats.

For future reference, please keep an on eye on the dates of past topics you'd have an interest in...Anything over 90 days is considered an archived topic and it's preferred that all members please create a new topic of their own vs bring one back up to the top unless that past topic was your own no matter the date....Thanks in advance regarding all that.

On to your questions at hand.....Unfortunately the 3.0's did have some issues with breaking starter bolts...One of Mercruisers past suggestions was to install a bracket to help support the other end of the starter as indicated in the following linked service bulletin...., MCM 3.0L, LX Starter Motor Bolt Breakage
http://www.boatfix.com/merc/bullet/95/95_03.PDF

 

[Scott Danforth]

change to a PMGR starter to help reduce the weight of the starter

make sure the bolts are torqued properly.

 

[OceanSun]

I've dealt with this problem multiple times across 3 different boats with the 3.0L engine. A rear bracket on the starter is key to prevention. I used to think it was the weight of the starter - especially with rough-water, offshore use. Switched to a PMGR starter to cut down on the weight and that didn't solve the problem. Love those starters (lighter, less battery draw, more torque, etc.) What causes the bolts to snap is the torque of the starter against the flywheel/engine compression. With the short distance between the two mounting bolts the starter can actually twist and snap off the bolts. With the third point of contact at the back of the starter it uses the length of the starter as leverage to keep it from twisting. I've seen guys rig up a strap hanger to support the weight of the starter and still snap bolts - that's not the problem. A solid bracket that holds to back of the starter against horizontal twist is the ticket.