sheered bolt ( can i do without it )

[piperdog7]

hello, just bought a used F4A, four stroke, 4 hp and the top right bolt of the bracket, swivel 2 ( 6E0-43312-02-8D ) has sheered off, loosed some other bolts, but havent seperated, so just re- tightened the loose bolts will it be okay without this bolt, thanks

[pstephens46]

Remove the bracket and the motor comes off, correct? I would want all four intact and properly tightened. Did the head break off leaving the rest of shaft in place? May not be that hard to remove the remains. A pic might get you some more specific advice.

[piperdog7]

hello, theres 6, no, it seems it has broken off flush with the otherside

[boscoe99]

What is the complete ID for the motor? You say you have a four stroke. F4. The part shown appears to be that for a two stroke 4 HP.

I would want to find out what is causing/caused the bolt to shear and the other bolts to loosen. I would replace the broken bolt. Why not? I know Yamaha likes to make sales of parts but I imagine there is a darn good reason why they used the number of bolts they used.

[piperdog7]

the image was just to give an idea of the part im on about, the bolts havent loosend on thier own, i loosened 3 of them before one sheered

[zenoahphobic]

the image was just to give an idea of the part im on about, the bolts havent loosend on thier own, i loosened 3 of them before one sheered

Thought so, common. I've never been able to drill out and extract a broken stainless steel bolt but others have. 6 bolts now 5, ah think of the extra speed you will get with that weight reduction
Many a time, and I think all of us, have had something that was missing a bolt or two, particularly when reassembling something and they are left over and we can't determine where they came from. Technically every bolt is necessary because they are evenly spaced to each other. But how often do you see a newer model with less fasteners than the last, but they would have revised the spread of the bolts. (I could not understand why some cars have 3, 4,5,6 wheel nuts).
The negative if you can't extract that bolt, could mean the engine vibration may loosen the other bolts or set up vibration in the part of the component dependant on that bolt or left hanging and break it through stress.

[rodbolt17]

that is why they make bullit point drill bits and heli-coils.