Lower mounting bolts - direction

[exeter27]

I have a 2004 F60TLRC engine that I'm re-assembling. For the lower mounting bolts (that go through the rubber shock mounts), does the head of the bolt face the rear of the engine or the front?

Pictures I took ahead of time show that the head of the bolt is towards the rear of the engine - and the nut screws onto the front side (towards transom). I'd totally trust my pictures, but a previous owner took some pieces apart - and maybe assembled wrongly? That's also what shows in the schematic: 2004 F60TLRC Yamaha Outboard BRACKET 2 Diagram and Parts .

But, a manual I have (admittedly it's for a 2005 TLRD - which is fuel injected) shows it the other way. Is it possible that Yamaha changed how this mounted between these years?

I'd think you'd want the nut towards the rear - to facilitate removing lower bolts without having to do the upper mounts (which requires removing the engine from the upper casing) at the same time. But everything suggests otherwise. I'm thinking I want it with the top of the bolt towards the rear.

What's the real answer? And, can I do it without removing the upper mounts? Thanks!!

Also, when I fully tighten the assembly, the rubber washer and flat washer are still wobbly - no tension on them. They are part of the 3 stacked washers (one is actually a bushing). That seems weird too. What is the torque for them (couldn't find in manual) and should they remain loose so that the outer cover can be attached?

[boscoe99]

The head of the bolt is aft. Nut is forward.

2004 F60TLRC Yamaha Outboard BRACKET 2 Diagram and Parts

[exeter27]

I saw that in the URL that I referenced. But a service manual for a 2005 shows it the other direction. And that's the question, did Yamaha change it year over year (the URL for the 2005 shows the other direction).

Ultimately, I don't think it matters from an engineering aspect - it will hold in either direction. But from a servicing aspect (i.e. ability to remove/replace a lower shock mount) it's better to have the nut to the rear. Otherwise, one must also loosen the upper mount bolts to allow enough movement to remove the lower shock mount bolt - and that requires removal of the engine from the upper casing).

Ultimately, what would rodbolt do?

[exeter27]

I've confirmed; you cannot install the lower shocks (with associated bolts and washers) with the head of the bolt aft (nut closest to transom) if the upper mounts are already installed.

I went by the local Yamaha dealer and the service manual shows that the top of the bolt should be aft for a 2004 F60. Interestingly, the 2005 F60 shows it just the opposite orientation as described above. Maybe Yamaha realized their error with respect to service. When I asked the dealership, they said it didn't really matter as they'd never just replace the lower dampers - but that they'd also do the uppers at the same time - with the assumption that they would be due for replacement as well. When I pointed out that a bolt could fail (like in mine) - he didn't answer.

For the life of me, it seems like it shouldn't matter as to orientation, except the service issue that I've now pointed out. Of course, as you tighten you create extra bolt length behind the nut. But, the cavity that holds this area has room for that.

So, I'm thinking of removing the top mounts, re-orienting the lower mounts as described in the 2004 manual and putting back together. Only downside is that I applied locktite red to the bolts. I'm sure I can get them apart - and then I can re-apply the locktite.

I'll likely do that tomorrow unless I hear from a yamaha technician that things are fine as they are...

[exeter27]

To close this out for any future visitor...

Well, I didn't hear from anyone. So, not daring to go against the service manual, I removed the upper mounts - backed out the upper unit, installed the lower mounts - and then slid all 4 bolts into their respective locations.

I still don't think it matters on orientation. But now if I need to remove the lower mounts - I'll have to remove the engine above to release the upper mounts. Feels wrong to me from that aspect, but feels good to match the service manual. Really would have talked to a Yamaha engineer.

Hopefully I never have to remove the lower (or have a failed upper) again....