xb21 motor height OT vs XOB

[xb03fs]

So I finally broke out a level and measured everything...and per my majic marker marks I was a bit surprised..Will the XOB run as high as the OT if it does I have a good bit of mph left................from where the OT ran best to where the XOB was was approx: 5-6 mph...hard to believe because that would make the xb21 go fishing two up as fast or faster than the xb2003 went fishing. Obviously the 21 cannot be empited as I don't have enough stuff to balance it without adding ballast solo as is...

200 XRI, 11.5" of setback


The 26 OT I sold. Ran 81 solo, 79 with a passenger, 1.5" above, lowered and it handled like crap. I would trim it and it would lose bite and sit down at this height. Nice and easy.

26XOB still working on maxing this one out but it currently running 1/8" above the pad at 79 with two...


My question is will it hold or does it need the much lower height due to the flare lifting the *** end up???? Does the flair ring provide approx so much more stern lift its like the motor is 1 3/8" higher? Or does the XOB have a lot of mph left in it...

PS the XOB drives way better with less imput just don't turn well...once I get the motor up maybe that will improve signiciantly ???Who knows.

 

[GotMyAlly]

With more diameter and blade area, I think the X-OB ought to easily run as high as the OT without slipping. I haven't measured exactly, but I know the sweet spot on the two on my boat is close. I ran my best speeds with the OT just below the pad. Have not ran that one above the pad.

 

[xb03fs]

the part that confused me the most is the XOB seemed to have less water pressure at 1/8 above as the OT had at 1.5 above...the both ran the same slip numbers.

The OT at the height of the XOB was a bear to drive and teh XOB drives great.. The OT required a ton of trim in comparison to life the boat where the XOB used about half as much.....

 

[xb03fs]

XOB did not like going higher.... It must naturally lift that extra 1 and 3/8. It felt right because it was pretty close the other day. I had 3/4 tank vs
1/4 was the only real different variable. Raising it induced a hop and low water pressure..I think with my 200 it will be a 78-79 mph boat.

 

[RobShaw-BasSport]

Has Robbie worked the diffuser (flare ring) on your X-OB yet?...

 

[xb03fs]

Todd is trading me a lower pitch and is going to trim the OD of the flare but leave the full length of it....don't know if I ever heard of this being done.

It took some convincing and am excited. It will be a totally unique prop at this point, the ring is not being cut off so exhust shoudl not cause it to slip/surge on holeshote and just the OD is being removed so it should take bit of the tail lift out I am complaing about.

I did not want it fully removed as I wanted to preserve as much of the accleration and holeshot as possible and gain handling and water pressure....the choices I had were no ring (neither of us liked that idea), a shorter but more pronounced ring (he said would provide less stern lift, I did not like the idea of mor eflare even if shorter), or trimming the OD of the ring (I thought this would give the best chance to presearve what I liked and minimize what I didn't).

I think he was a little taken aback I was complaining about a prop slipping 5% with two on board laoded to fish that came out of the hole fine and accelerated well....(78 and change at 6200 rpms)

At the end of the day I may be wrong.......maybe not...maybe it will be the next tweak that everyone wants.

The lower pitch deal is I want more rpms....6400/6500 minimum. If I can push the prop harder due to the handling improvements as i am thinking.. maybe just maybe I can get it to my limiter if not. I pushed for the changes and if I ruined a perfectly good prop its at my request and I will own it.

 

[reward69]

The OB has a lot of stern lift, I have a 28 OB and it really gets the stern out of the water.

 

[xb03fs]

Yeah working with Todd on that stern lift deal...ideally speaking looking for him to remove some stern lift by shaving the OD of the ring.. Ideally speaking it would make it aobut half the stern lift of the XOB and double the stern lift of the OT

 

[JWW8]

How high are you XB-21 guys with 3.0L motors running the XOBs?

 

[RedAllison]

How high are you XB-21 guys with 3.0L motors running the XOBs?

The gearcase will suck air well before the prop will let go. But running 21s with 3.0s at full boogy jacked that high AINT recommended!!! :gasp :help

 

[JWW8]

I am still learning with mine, but haven't been running it above even pad. How high do you run yours?

 

[silverbullet02]

PS the XOB drives way better with less imput just don't turn well...once I get the motor up maybe that will improve signiciantly ???Who knows.

What do you mean by doesn't turn well? What kinda turns are we talking about here. Can't say I ever noticed a difference between props, trim it down some and turn the wheel.

 

[xb03fs]

Tught River turns at wot a couple bumps from max trim...it turned well 65 and below.. On a lake there would it would never be noticed.


Todd made me something special to try.. The last couple trips have been family (ie no wot tight turn) trips to a lake...I think it's gonna a beast a beast just from what little I have been able to get on it.

 

[RedAllison]

SURELY this "wot turns" talk is a joke???

Foolishness! Wear your jacket & let kin know your whereabouts when trying such stunts!!!

 

[xb03fs]

remember Red I just have a 200..it was an 85-87 mph motor on my xb2003 every day and is a high 70's barely 80 motor on my xb21 WOT aitnt that fast....

I just want to be able to make turns I made in the 2003 at 80-82 in my xb21 at 75 or so...

With the before the tweak it I left it trimmed where it was locked in it felt like the pad was sliding a little through the turns...if I bumped the trim down enough to wet more of the pad it felt like the bow wanted to catch.

the little river:

 

[silverbullet02]

I'd like using something like this more in those water conditions. Turns better, handles better, accelerates better...sounds like the whole package to me!

 

[aaronmt]

WOT throttle- lock to lock-hard turns- down river isn't recommended.....that is unless you are in a sprint boat

 

[GotMyAlly]

I am still learning with mine, but haven't been running it above even pad. How high do you run yours?

What year is your boat?

 

[xb03fs]

...............

 

[GotMyAlly]

Sounds like you're running a slalom course in your boat! I'd think a little more motor depth would be prudent if you are planning to put it through it's paces like that.