Yamaha SHO Solid mounts and lower unit mods

[xb03fs]

What does it take to make one run on an Allison?

Are they like a 2.5 merc where it is easy to get one set of solid mounts in and the whole motor has to come off for the other set?

Will one set work? Are the regular mounts stiff enough that just replacing the easy to access mounts is acceptable?

The lower unit looks like a good shape is it as easy as building a torque tab and epoxying the upper screen on the nose cone?

505 lbs is not so terrible for a xb21

[xb03fs]

Motor needs to come apart call superbender 6315636277 ep marine or pm him

Not in the market till probably this time next year. I would hate to waste a guys time. I was really disappointed in Mercury not offering a 505 or less lb 4 stroke so I am starting to think a 225 SHO is in order..since it has to have motor mounts and a lower modded a used 2012-2013-2014 after their initial issues where fixed would be what I am looing for. 200/225 serial number required for sure, I know a 200 could be made into a 225 pretty easily by hydrotech, which is what my boat is rated for...

[xb03fs]

I sent him a message, if things fall into place I would definatly be interested early next year. I have just begun reading up on SHO as Mercury again failed to provide a good option for us at the Miami show.

I have read the 2010 and 2011 has some issues, are the 2012 and newer pretty much bulletproof?

[GETBOATS]

What does it take to make one run on an Allison?

Are they like a 2.5 merc where it is easy to get one set of solid mounts in and the whole motor has to come off for the other set?

Will one set work? Are the regular mounts stiff enough that just replacing the easy to access mounts is acceptable?

The lower unit looks like a good shape is it as easy as building a torque tab and epoxying the upper screen on the nose cone?

505 lbs is not so terrible for a xb21

Solid mounts make a huge difference, power head has to come off, lower unit and mid section to get to the top ones, 5 hours start to finish, power head gasket is all that's needed. this boat runs 103 w/ 3 blade 15 x 34 cleaver with only mounts and simon flash.

[Don Geiger]

I love my sho you do need monts thow

[FishingBen]

Very interested in this thread for a future profect. Don Geiger that is the coolest SHO I've ever seen would like to know about your motor setup. Ben

[Don Geiger]

Very interested in this thread for a future profect. Don Geiger that is the coolest SHO I've ever seen would like to know about your motor setup. Ben

Call me 1607 760 3105 couldnt be happier with it great take off 7 mph faster than my 3.1 250 vmax with tuner reads and I have only had this sho 1summer and you can pull up slalom skier without any problem and gas milage is great no smoke in the cove either a little quite thow

[whipper]

Very cool! The simon flash is to 7000 right? Sweet looking motors!

[GETBOATS]

Very cool! The simon flash is to 7000 right? Sweet looking motors!

Simon will put the limit where you want it, but this one was set higher than that, we hold it somewhere between 6700 and 6900

[Don Geiger]

Simon will put the limit where you want it, but this one was set higher than that, we hold it somewhere between 6700 and 6900

How many hours at over 6600 I put 120 hr this sumer but its on a 11mile lake so it alot of crusing at 65 and some wide open 6 to10 times a weakend

[GETBOATS]

how many hours at over 6600 i put 120 hr this sumer but its on a 11mile lake so it alot of crusing at 65 and some wide open 6 to10 times a weakend

about half of the total 25 hrs on engine

[Don Geiger]

I have ben toled over 7000 not recommended like to see someone port one

[Keith E.]

Necro Post Alert! I am researching Yamaha setups on Allisons as I plan to install one on my recently acquired XTB21.

TIA,
Keith

[I Belong On The Water]

I have a 250 sho on my Allison GS. Have only been out once and didn’t even come close to pushing it. Right now the propshaft is 3.25” below the pad, so I have lots of tweaking/setup to do yet

[David]

It’s going to take more steering with the motor that low, and it won’t be as fast as it could. But as noted, you have tweaking to go.

My SS2000 is easier to drive with the prop higher than that.

Mr Allison never recommended the new heavy engines on his 20’ boats, but there are more setup that way as time passes. My understanding is that the non ratcheting gearcases are more likely to induce a bat turn, and the heavier higher cg motors are more likely to induce a roll during the bat turn.

Don’t get carried away with trim and engine height and you will hacpve a fast fun fuel efficient boat.