Sho on xb03 or 02?

[hirks]

I have an 03 with a tuned sho and stock lower. I'm looking to prop it, anyone suggest a good all round loaded to fish two up prop?

[scj]

I have an 03 with a tuned sho and stock lower. I'm looking to prop it, anyone suggest a good all round loaded to fish two up prop?

As big as the SHO lower is, I’d look at props that do not have a bunch of lift. Running a stock 225 SHO on a XB-21, about a dozen props were tried and none of them would run better than mid eighties before they would start to blow out.

[hirks]

Ya running a 27 bravo xs now, too much stern lift. I need something with bow lift.

[scj]

Yeah, I should have clarified stern lift is the issue running stock SHO lower.

Have you tried any 3 blade props?

[PSM207]

Yeah, I should have clarified stern lift is the issue running stock SHO lower.

Have you tried any 3 blade props?

scj - I'm not quite understanding your comment on stern lift for the stock SHO L/U. Can you elaborate on this?

[hirks]

I have only ran the Bravo. Boat runs too wet because there is so much stern lift it keeps the bow from lifting enough. I have to over trim it to lift free. It only runs 80mph turning 6200ish until it pops and breaks free but it's to loose with so much trim to run like that. I'm looking to prop it to run 90ish. Any experience running overdubs or should I stick to 3 blade barrel props?

[scj]

scj - I'm not quite understanding your comment on stern lift for the stock SHO L/U. Can you elaborate on this?

Looks like you’re running a SHO on an Allison now and I have no clue how you set yours up and what your experience is with it but the XB-21 tested 5 or 6 years ago was only able to run mid 80’s as the lower unit was lifting the boat at speed. The stock lower does not have low water pick ups so it has to be ran lower than a sport master to keep water pressure. The boat tested was not loaded at all other than two people in it. My recollection is 15 props were tested that day and every one of them wanted to break loose in the mid eighties. Just too much mass on the lower unit for high speeds. Running surfacing props on a lower unit with water pick ups above the nose of the lower makes no sense to me.

In my personal opinion, no way I’d try to push a stock SHO to 90, especially in a 20’ boat unless your life insurance is up to date and your affairs are in order. You’re going to get wet!

[Gary Morgan]

I just don’t get it, folks. When the 20-footers were designed, there were no 500+ pound motors, so they weren’t considered in said design. As soon as the big motors came out, the designer warned all who would listen not to put them on his 20-footers. Now after 25 years and several injuries and deaths, we sit here trying to figure out how to make it work. Either sell the boat or sell the engine. They don’t belong together. I still can’t understand how the Allisons were sued and had to pay money in the case in Louisiana when the facts are what they are.

[fishnfireman]

I just don’t get it, folks. When the 20-footers were designed, there were no 500+ pound motors, so they weren’t considered in said design. As soon as the big motors came out, the designer warned all who would listen not to put them on his 20-footers. Now after 25 years and several injuries and deaths, we sit here trying to figure out how to make it work. Either sell the boat or sell the engine. They don’t belong together. I still can’t understand how the Allisons were sued and had to pay money in the case in Louisiana when the facts are what they are.

Guess I missed that.

[Keith E.]

I have an 03 with a tuned sho and stock lower. I'm looking to prop it, anyone suggest a good all round loaded to fish two up prop?

Have you considered getting your lower coned or acquiring a coned lower. Try to find someone that's familiar with Allison setup when doing so. Your prop search would be easier after that.

Best of Luck,
Keith

ETA: I just acquired an XTB21 and am currently researching prices on a 200SHO.

[22R]

Guess I missed that.

I missed it too any details of the case ??

22R

[Tim Powell]

All I can add is Allison does not allow us dealers to install anything larger than a 2.5L or a new 150 Fourstroke on the 20' boats. A 150 SHO might be interesting

[revlimiter]

Guess I missed that.

Me too.

[aj06bolt12r]

That boat is not going to work good at higher speeds until you either get a legit nose cone with real low water pickups on your SHO lower unit or better yet modify a Merc Sportmaster LU to work with your SHO. Yes the engine is heavier than what Allison recommends, but that is not what is causing your current issue.. You are just having to run the propshaft too low in relation to the pad in order to maintain water pressure.. Its never going to drive good like that on your hull. If you have the lip you need to be about 1/4" below pad depending on how much setback you are running. If you have no lip you will probably end up well over 1" above pad. I don't think any prop in the world can compensate for running the lower unit too deep in the water on an Allison XB03 hull... Also I have been told by a much better Allison pilot than myself that if you want to run a Bravo on a 20ft Allison you want to make sure 100% of the flare is removed from the end of the prop barrel.

[aj06bolt12r]

All I can add is Allison does not allow us dealers to install anything larger than a 2.5L or a new 150 Fourstroke on the 20' boats. A 150 SHO might be interesting

It would be interesting.. I thought hard about putting a 175 SHO on my XB03. 175 instead of 150 for the taller gear ratio. Plus either engine can be tuned to something like 230HP.... But even those 4CLY SHO's weigh about 480lbs... Not counting the cowl, prop or any fluids or steering.... Hell, my 3.4 ETEC on 16" mid only weighs 485LBS and that is counting hydraulic steering, lower unit oil, propeller, primed fuel system and the cowl! My only point being that the power to weight ratio is pretty bad on the 4CLY Yamahas.. Also they are not cheap, and then you still need to pay for solid engine mounts and a good nose cone job if you want to run an Allison like it was designed to be run.

Bring back the 2.5 Promax! Defund the EPA!

Ok rant over.

[scj]

Mercury 150 hp weighs 456 so not enough to worry about between it and the SHO 150/175.
I lost 120 + pounds in my boat by switching out my AGM trolling batteries to lithium. The 20’ boats are designed to carry the batteries in the rear end since you set further forward and moving them to the front was a mistake running a 225x. It would not carry the bow running a 26 promax. This was in a xb2003 btw.
A responsible person would offset the weight of a 500+ pound engine with lighter batteries, etc and we all know many 2002/2003’s were ran with 260/280 engines with no issues for years so I doubt a 231 hp engine would be an issue. A SHO 200 weighs 530 to 550 pounds so running that engine should be carefully set up or just avoided altogether on a xb2003.

Darris did not like seeing a 2 stroke 250 Pro XS with a sportmaster hanging on the back of the XTB 21 I bought last year and it only weighs 505. I reduced the setback, went to a Lithium trolling battery and my boat floats 2” higher in the rear than my buddy’s XTB with a Promax 225 and three lead acid batteries. It’s all about setup IMO and I’m not looking to go 90+ mph anymore.