20hp power head removal issue

[ClayColl]

So I destroyed the upper casing pulling the power head off. I have a new casing but can’t for the life of me get the power head back on.
The exhaust tube doesn’t fit in the casing. What am I missing? The manual I have says nothing about it.

[99yam40]

someone might be able to help if they knew what power head, exhaust tube, and what upper casing you are dealing with

[boscoe99]

Yes. Need the complete model identity. And the part number of the replacement casing. Possibly a description as to how the casing got damaged.

[ClayColl]

It’s a 20 DMHS. The casing was broken when removing the power head. I had every thing undone and the power head would only lift out about an inch or two. It was catching at the bottom od the exhaust tube and where the bottom seal on the exhaust tube seats.

I’m wondering if the exhaust tube has somehow been squashed out of shape, but not sure how or why that would happen. Outboard is secondhand though.

I’ll try and get some photos as I’m lost for how to explain it.

[boscoe99]

I am at a complete loss as to how something on the power plant can catch something within the upper casing. The power plant sits on a base gasket. The base gasket sits on the upper casing. There is nothing that runs from the bottom of the power plant into the upper casing.

Methinks you need to take the motor to a trained Yamaha mechanic.

[panasonic]

It’s a 20 DMHS. The casing was broken when removing the power head. I had every thing undone and the power head would only lift out about an inch or two. It was catching at the bottom od the exhaust tube and where the bottom seal on the exhaust tube seats.

I’m wondering if the exhaust tube has somehow been squashed out of shape, but not sure how or why that would happen. Outboard is secondhand though.

I’ll try and get some photos as I’m lost for how to explain it.

Post some pictures if you can....

[ClayColl]

I am at a complete loss as to how something on the power plant can catch something within the upper casing. The power plant sits on a base gasket. The base gasket sits on the upper casing. There is nothing that runs from the bottom of the power plant into the upper casing.

Methinks you need to take the motor to a trained Yamaha mechanic.

It’s not the motor hanging up it’s the exhaust down in the leg

[ClayColl]

New and old leg cases for comparison of where it’s broken out. And the exhaust from the bottom. It’s like trying to fit a long rectangle in a square hole. Thinking someone’s done something to squash the exhaust out of shape or something.

[panasonic]

Perhaps you have the wrong exhaust pipe and that's why you had trouble getting it out of the leg in the first place! You said it was used so you dont know what someone else has done in the past...

[ClayColl]

Perhaps you have the wrong exhaust pipe and that's why you had trouble getting it out of the leg in the first place! You said it was used so you dont know what someone else has done in the past...

Thought that too but don’t know how they could have gotten it in without damaging the leg casing.

[99yam40]

seems to me that Boscoe mentioned that the exhaust is not part of the power head, so it should not have come out when you pulled the power head

[boscoe99]

That's the part I am not understanding. Lifting the power plant causing some damage to a part down below that is.

[zenoahphobic]

seems to me that Boscoe mentioned that the exhaust is not part of the power head, so it should not have come out when you pulled the power head

My guess Yam40 is right. The power head should have come free from the exhaust tube (stuck gasket) and maybe not all the bolts(nuts) were undone to cause you to “rip” this out of the lower leg.
This leads to a problem, you also have a lower unit without the exhaust tube, leaving how this come about aside, you need to undo the exhaust tube from the powerhead.
It then will be easier to install that exhaust tube first. But I suspect the lower leg needs to be dismantled to do this.

With this in mind, without part numbers etc., there is always the possibility some incompatibility, some change in that model range that is causing the miss fitting.