Starter bolts Merc 260

[Southtowns27]

Hi guys. I'm looking for new starter bolts for my 1986 Mercruiser 260 (Chevy 350). Does anyone know off hand what the thread is as well as the overall length? My starter burned up at the end of last season and I had it rebuilt over the winter. The starter bolt closest to the bellhousing was a real bugger to get out because the head of it was rubbing on the bellhousing sheetmetal dust cover. I'm thinking a couple of allen socket head bolts will make it easier to put back together. My boat is still shrinkwrapped and of course the bolts are onboard so I just can't go look quick.. Any help is appreciated!

 

[kenny nunez]

Go to a Cheverolet dealer and buy new bolts. You can also get them through a Mercruiser dealer. The replacement bolts may also have an extended 9/16” hex which really helps. Too bad you had the original starter rebuilt when you could have gotten the newer, lighter PMGR style.

 

[Southtowns27]

Go to a Cheverolet dealer and buy new bolts. You can also get them through a Mercruiser dealer. The replacement bolts may also have an extended 9/16” hex which really helps. Too bad you had the original starter rebuilt when you could have gotten the newer, lighter PMGR style.

The hex head *IS* the problem, hence my desire to find allen socket head bolts... Those won't be found at the dealer. The rebuild only cost me $80, so I'm good with that...

 

[kenny nunez]

Those starter bolts are special made as you can see and are grade 8. With the extended hex head you should have no problem with a socket.
I can feel your pain about the clearance problem, there may be a 5/16” bolt and nut that is used to bolt the dust shield to the adapter/flywheel housing which is positioned too close to the inner starter bolt. I have had to remove that bolt to get a straight grab on the inner starter bolt quite often.

 

[Bondo]

Those starter bolts are special made as you can see and are grade 8. With the extended hex head you should have no problem with a socket.
I can feel your pain about the clearance problem, there may be a 5/16” bolt and nut that is used to bolt the dust shield to the adapter/flywheel housing which is positioned too close to the inner starter bolt. I have had to remove that bolt to get a straight grab on the inner starter bolt quite often.

Ayuh,..... Agreed, starter bolts, gotta be starter bolts, not something out of a bin,.....

Merc makes some with a 1/2" hex, to help with the clearance issue,.....

I've been known to trim off that bit of flywheel cover, that gets in the way,....

 

[Southtowns27]

Ayuh,..... Agreed, starter bolts, gotta be starter bolts, not something out of a bin,.....

Merc makes some with a 1/2" hex, to help with the clearance issue,.....

I've been known to trim off that bit of flywheel cover, that gets in the way,....

Ayuh,..... Agreed, starter bolts, gotta be starter bolts, not something out of a bin,.....

Merc makes some with a 1/2" hex, to help with the clearance issue,.....

I've been known to trim off that bit of flywheel cover, that gets in the way,....

I'm not dumb enough to put grade 2 cheapy hardware store bolts in it. I'm planning on using grade 8 allen socket head bolts.... I'm 95% sure they're 3/8-16 but I need the length. I put a Chevy 327 in my Jeep but it's got a mini starter on it so the bolt length is different...
And as far as trimming the cover, forget it without pulling the engine. I could barely get that starter bolt out let alone reach back there to do anything with the cover at arms length. The engine mounting stringers are so tall that I had to lay on my back, head down in the bilge, feet up in the air, with my right arm fully extended under the engine to get to the bolts...

 

[stang32]

if you put grade 8 bolts in a starter hole, if there is an issue where a starter bolt normally break, the grade 8 will not however it will crack the engine block, the bolts for the starter are not grade 8, maybe 5. gm sells the new bolts with 1/2" heads whiuch will allow dust shield clearance

 

[Scott Danforth]

starter bolts are custom alloy, custom temper and custom knurled for a reason. if you want more room, swap out your direct drive 35# starter for a newer PMGR 13# starter. not only will you have more room, easier to get to, it will spin your motor faster.