2-Stroke 15hp Removing lower unit

[O2Addict]

Very simple question, in removing the lower unit from a 15hp 2-stroke, I cannot disconnect the shift rod. Does the shift rod disconnect from the powerhead or from the lower unit?

[99yam40]

I really do not know if the age of the motor would have a lot to do with the answer you are looking for, but a model # is always a good thing to post when asking questions on motors. The 15 hp 2 stroke has been made for many years

[O2Addict]

It is the 15FMH

[rodbolt17]

just above the gearcase is a barrel nut and jam nut.
using 2 10mm open end wrenchs break the jam nut and barrel nut free.
thread the barrel nut UP.
easiest to remove and install with shifter in reverse.

its NOT an adjustment point.
don't even try no matter how tempting.

IF you manage to pull the shift rod UP and it disengages the shift plunger it WILL require propshaft removal to reassemble.

[O2Addict]

Ok I could loosen the locking nut easily, but the barrel nut won't turn. As I try and turn it, it feels like the shifter rod going up to the powerhead is torquing with it. The rod runs inside the intermediate housing so I cannot grip it, how is it best to break it free?

[99yam40]

You might try disconnecting from the top end to see if you can pull the lower with the rod attached, and then work on breaking the barrel not free from the rod.

I had a 30 that i never did get it to break free even with heat and beating on the nut with it out on a vice. Spent too many years out on the salt water. But I did not have a Ox torch

[rodbolt17]

heat,prayer, wailing and gnashing of teeth.

however most likely you will break the pin just below the power head.
then it will require powerhead removal as well.

yearly maint and a dob of grease will prevent future issues.

[O2Addict]

What is the best manual for these things, and where can I see an exploded view of it? I have the Sealoc manual which is a good generic manual, but does not have this sort of detail that I need.

[O2Addict]

Ok, so the shifter broke right at the top of the barrel nut. Going to try and reconnect using a longer barrel nut otherwise I will have to pull the head. Is the head as easy as it seems? Just undo the 6 bolts joining the intermediate housing?

[rodbolt17]

undo any throttle links and reverse lockout links.
undo any ground and kill switch connections.
remove fuel lines as nessasary.
remove the powerhead mounting bolts.
remove the powerhead.
barring corrosion that powerhead should be on the bench in 20 minutes.

no engine lift nessasary.

[TownsendsFJR1300]

May I suggest, if the barrel nut is froze and you need a clean useable shaft the following:

An air compressor with a small hand held cutting tool would work best. (a Dremel with a HD disc should work as well)

Simply take the cutting disc to the barrel nut going very slow and STOPPING once you start to see threads. (Cover up the LU so debris doesn't get to it)

If it still doesn't break loose, do the same to the other side of the barrel nut. There literally won't be anything left of the barret nut for it to hang on to. It is critical NOT TO DAMAGE the threaded, LU shofter shaft obviously.

OMO, I'd replace that upper shifter shaft and barrel nut with OEM parts and apply anti-seize.

[99yam40]

Ok, so the shifter broke right at the top of the barrel nut. Going to try and reconnect using a longer barrel nut otherwise I will have to pull the head. Is the head as easy as it seems? Just undo the 6 bolts joining the intermediate housing?

seems someone did not read the posts if he is offering a way to remove the barrel nut

[TownsendsFJR1300]

What is the best manual for these things, and where can I see an exploded view of it? I have the Sealoc manual which is a good generic manual, but does not have this sort of detail that I need.

What year engine and model # is it exactly?

The section up above "Purchase Yamaha Parts" in RED, once your information is entered will give you a full illustration / parts fisch (and the order in which they go) and is usually very, very helpfull...

IE, a 2000 15 HP (parts 33 and 34):

[O2Addict]

33 and 35 are what I need. My model is not listed, it is a 2008 15FMH. Also do I need to replace the gasket between the powerhead and the intermediate housing when I pull the power?

thanks

[TownsendsFJR1300]

33 and 35 are what I need. My model is not listed, it is a 2008 15FMH. Also do I need to replace the gasket between the powerhead and the intermediate housing when I pull the power?

thanks

For my F150, that gasket is NOT re-usable, I'd have to guestamate yours isn't either.

Is your engine a US engine or where was its original location? As you said, it not listed in the US parts fisch.

You may (if outside the US) go to your local Yamaha dealer for the part or at least get a part #, then order on-line. I'm sure that parts been used in numerous other engines...