Help with hole shot.

[hooken203]

2011 XB21 running a 250 SHO 1.75 gear 28 QIVXOB. A lot of bow rise and it just seems slow coming out. The skid planner was cut off even with the transom so I replaced it with a stock length and it didn't seem to change anything. I have tried various engine heights and with it even with the pad it's better but still slow. I have a 26 Bravo XS that does make it better but it still has a lot of bow rise. Do these boats come with 2 degree wedges between the transom and the 2 inch set back plates? If so can you see them? They may have been removed by previous owner.
What else can I try?

 

[whipper]

15 inch dia props seem to work best on the Big blocks from what Ive read. This artical is a good one for setup. He had 8inches of setback and said it ran faster then the 250xs from an idle start pluss better mid range. Most guys are running 8-10 inches of setback with the 250xs. The SHO I would think 10+ would be best since you cant run higher gearcase heights would be my guess. More setback and 15+ inch wheels with the 1.75 gears with all there torque should push you flatter. The driver in the artical is also big lad!! if that makes a difference? If your close to the hull the hole your digging is effecting the stern making it fall in the hole it sounds like. By moving into cleaner water our back this might help? Just what I think. Ive heard of this happening before. With the difference in gear case on the Yamaha it just might be the case?:] http://www.fishingworld.com/vDealers/TN/LindasLakesideMarine/UploadedImages/SiteImages/TrailerBoats2010issu-AllisonBoats.pdf

 

[hooken203]

That article is part of the reason I bought this boat. I had the engine already. The prop I am running is 15 inch dia. I am at 9.5 inches of set back. I have a modified lower unit coming that has the water pick up down low under the nose of the bullet. So if having the engine higher helps the hole shot it should be better.

 

[GotMyAlly]

Sounds like you've got more setback than most 21 owners. The wedges will help, too.

 

[procomp]

Maybe try the beach ball trick in the jackplate. Cheap to try.
Do you have a cavitation plate on the motor?

 

[whipper]

Maybe try the beach ball trick in the jackplate. Cheap to try.
Do you have a cavitation plate on the motor?

Both excellent things to do. Cav plate is night and day on my lighter motor as well as floatation in the setback On a heavier motor even better. The flotation helps the stern ride higher at rest and when you take off because the stern is already higher plains off flatter as well as helps with the stern from sinking into the hole. The Cav plate is also the ticket for faster hole shots specially designed for Allisons. Pretty much all drag boats run some kind of cav modification they really are wonderful additions.

There was an article on S&F about when they tested the sho on a 21ft Tuff performance boat. The prop was a real big factor because of the massive torque these motors made. It sounds like your already on the road to better setup that can only help in every way. No two boats are created equal as well as motors and props. We all have to personalize things to get what we want. I cant wait to hear how your set runs with the changes to the low water pickups and prop selections.
Ya know the more I think about it most of the guys with these motors are running 30 pitched Brovos with the vent holes plugged. I remember Brian Harden saying that because the SHO has variable timing if the prop slips or is allowed to vent threw the holes in the prop they struggle to get on plain because the motor will want to unload coming on plane. With the holes plugged they will yank you out of the hole faster than anything else. This could be the problem your having if your holes arnt plugged shes unloading on ya?. Also running a smaller wheel like a 28. You should be able to run a 30 no problem at all and take off like a banshee with that hull. Just a thought from finding everything i could about this motors performance from every site on the planet.:big grin Ive had lots of days off and the weather isnt that great so been spending WAY to much time looking at the pros and cons of these larger displacement motors.

So personally I think with the motor back in as you have it in cleaner water, the Worthy mods to the gearcase to get it up a little more, and making sure the holes are covered on the props so the motor cant unload your off to the races so to speech. That ventilating thing sounds like its a big deal with these motors unlike we all have been used to with 2.5,s and the mercs, the 4 strokes don't like that spooling up way we used to do..So cant break the prop loose is the key hear with no vent holes.

 

[hooken203]

Will have to try the beach ball in the jack plate. That 26 bravo xs has 4 1 inch holes that cant be plugged and its hole shot is alot better without as much spool up as the 28 qivxob if i leave all the holes open on the 28 it spins up to about 5k when punched from a slow idle. I dont think I could run a 30 pitch top end RPM on the current set up is about 5600. These SHOs are very good on bottom end and mid range but they lack on top end power. Thats why I have this question I have a boat and engine combo thats supposed to be great on the hole shot and its far from it. The guy that had this boat before me did alot of messing around with the set up. So I wanted to know if these
XB21s came with the 2 degree wedges from the factory? Maybe he removed them?

 

[procomp]

Just put a Reynolds cavitation plate on a buddies 21 checkmate with 300x and he loves it. Big difference.

 

[FFWD]

Wedges are going to be necessary with your setup. I am working on the setup up of a XB21 Bassport Pro with a 200XS. Wedges and a cavitation plate foil make a huge difference in the bow rise coming out of the hole and this engine is a good 50lbs lighter than your SHO so you would see an even bigger decrease in bow rise. Allison has both 1/2" wedges and 1" wedges. The 1" was too much for this setup. Are you running the Bassport Pro or the 2+2? The setup will be a little different depending on which deck layout you have. I think you will be amazed at how much different it will run once you get a lower unit that you can raise up higher. These hulls need to be put on the pad at a lower transom height and then raise the jackplate up as you increase speed. With this current setup I am running out of water pressure before I loose prop bite.

 

[xb03fs]

You sure the wedges are needed with the 200xs? I do not run the wedges with my 200 efi. If I trim under to much it hurts holeshot...I need a trim gauge to get a more consistent holeshot eyeballing it is ok but not ideal.

I am 11.5 back running 1/2 above running 81/82 consitantly and breaking into 83 ocasionally

 

[FFWD]

Yes the wedges definitely make a difference in holeshot. This is a Bassport pro which has the center of gravity further back than your 2+2. The owner of the boat fishes heavy as well so it stays loaded. I tried moving the trolling motor batteries to the front but it killed top end.

 

[hooken203]

My boat is a Pro also. I have more tackle in there than 6 people need and with me in there yeah you could say I fish heavy. Again I thought these boats came with 2 degree wedges in there from the factory.

 

[FFWD]

The wedges go between the engine and the jackplate and the boats do not come from Allison with the engines installed. So it is up to whoever rigged the boat to decide if and how much wedge to install.

 

[RobShaw-BasSport]

hooken, most of us are running 2 degree NEGATIVE wedges and no more than 6" of setback (CMC hyd jack plate plus the wedges...a little more than 6" to be exact). did the prior owner also mess around with battery placement? the 1:75 gears should be launching that boat!

I'm pretty sure the negative wedges are shipped with the boat to the dealer but Im not sure. The neg wedges allows you to tuck the motor in deeper.

 

[hooken203]

Robert my boat has the set back plates that I think are 2 1/2 inches. I thought all of the XB 21s came with. Then a Bobs Action jack 6 inches then a 3/4 inch spacer and another 1/2 inch for the powerpole bracket. I have a boat and engine combination that like you said should be a rocket out of the hole and it is just like all the other boats at blast off. I have been getting a lot of good info in this post. I will get the modified lower unit on it and see how it runs. Then get a set of wedges from FFWD and get them stuck in there and see how that works. Thanks for all the advice.

 

[RobShaw-BasSport]

You are correct about the 2" spacers...I have those as well (forgot all about that!)

 

[GotMyAlly]

Are the power poles dragging when you take off?

 

[Allyfishing]

Robert my boat has the set back plates that I think are 2 1/2 inches. I thought all of the XB 21s came with. Then a Bobs Action jack 6 inches then a 3/4 inch spacer and another 1/2 inch for the powerpole bracket. I have a boat and engine combination that like you said should be a rocket out of the hole and it is just like all the other boats at blast off. I have been getting a lot of good info in this post. I will get the modified lower unit on it and see how it runs. Then get a set of wedges from FFWD and get them stuck in there and see how that works. Thanks for all the advice.

OK, so now you have provided these guys with the information they need to start helping you that you omitted in the original post.

FROM THE FACTORY, there is a set of 2.5" spacers attached to the transom then a 5.5" CMC hydraulic JP and then a set of 1/2" NEGATIVE wedges (that allows the motor to be "tucked" under further on hole shot) for a total of 8.5" of total setback.

AND, you have a power pole and bracket which may have affected your holeshot as well. I know of a few 21 owners that have added the power poles that has affected their holeshot and top end.

the more brackets and spacers and wedges you add is going to set the engine deeper in the water unless you compensate by raising the motor up higher on the JP (until you run out of holes on the mounting brackets).

You already have an engine without low water pickups and are running way deeper than anyone with a 250XS/sporty.

I have a 2013 - 250XS/1.75 gears with a 30P Bravo dual PVS holes (4 outer closed) and I have no problem at all with hole shot. I removed my pair of lead acid batteries (110LB's) with one 31.5 LB lithium pro and i did notice a slight increase in holeshot time. I moved my cranking battery (80LB die hard AGM) forward in the rear port compartment (basically against the front wall of that compartment) and holeshot improved.

With my 295LB fishing partner and full fuel hole shot was still good but more bow rise than I cared for. I talked to Lee Sanderson and he advised an Allison foil. He sent me one, I installed it and that put a smile on my face from ear to ear.

CAll lee sanderson and tell him what you've got and ask him to build you a Bravo and get an ally foil.

 

[hooken203]

Thanks to all those that have replied it has been very helpful. When this boat arrived in my drive way I had only looked at one and sat in it. So my knowledge of the boat was minimal to say the least. I am the rigging guy so I do all my own work. Nothing was left out of my original post that should have misled anyone. My set back is 9 1/4 inches.
To answer a couple questions I do have one power pole on the port side and yes it does drag for about 2 seconds on a WOT start. There is no way to avoid this drag due to the way the brackets are made. The hole shot was bad before this was installed.
As for my engine setting deeper this is true when running I am at 1 3/4 to 1 1/2 below the pad. My engine is set so the prop shaft is even with the bottom of the boat at mid travel. I have tried it with the engine all the down and all the way up. Not really much difference either way. I just got the prop back from Todd and he did some things to help the hole shot also the HydroTec modified lower unit came in today so all that may make a big difference.
I do not have the wedges installed as they weren't with the boat when I got it. This winter I plan on installing the other power pole and will install the wedges then. Maybe it's as good as it gets. As I said before when I get to compare with other 20 plus foot boats with the same power I don't see that this boat is exceptional and I thought it would be.

 

[Allyfishing]

"Nothing was left out of my original post that should have misled anyone."

I hope you didn't think I was being a smart a** for saying that we now have all the info. We didn't know up front which 21 or that you had power poles. Or a few other bits and pieces of info until later in the post. that was not my intention.

If it were me I would call and talk to Mr. Allison and tell him exactly what you have and see if he can figure out what's going on.

Another thing I thought of right away is unloading the boat with the tackle for 6 people!!! (that was supposed to be funny) Start out fresh and work from there.

Don't get discouraged, these boats are exceptional, but they do require more attention to setup over any other boat. I stated another owner having issues with hole shot with power poles and that was on a 2+2. The Pro is a different boat and IMHO will suffer even more with that extra drag back there.

Make the call to Mr. Allison.