Vegas XT motor height

I just bought my rig a couple of weeks ago, so I still have a few questions about it. I don't wish to ever experience a blowout, so I've been a little hesitant to jack the Merc up a whole lot. My VegasXT seems like it needs a lot of positive trim to maintain bow lift. If I try to trim it back in a little bit once I'm aired out, the hull digs in and it slows down. I probably need more setback, but I'm not messing with that. Could I use a different prop? Do I need to jack it higher? I would like to hear some suggestions from XT owners on trim/height settings. I'm running a Hydromotive nosecone/lwpu, Land&Sea 6" hydraulic jackplate, and a 28" Merc chopper.
-Chad the pyromaniac

[AnthonySS]

Dear CHAD,

Congratulations on your VEGAS XT purchase. These are all around great performance rides, ..Lots of space for gear and people, nice 20’ length that will get you home in the ruff stuff and capable good top end with 200 hp (78-82 mph)

10 ½” of setback would be great, however I would focus on the fundamentals and making sure it is safely setup first. The safety items would include kill switch, Foot Throttle, remote trim, solid mounts, dual steering a good PFD and Helmut.

Assuming you have such items as Jack plate and Low water pickup, focus on proper engine height. I would set it up so the prop shaft C/L is level with the Pad. This should produce good results for both top end and limit the axis you have to prevent chine walking.

The XT takes a little to get used too as it has a stuck/unstuck sensation in the 65-70 mph range. It is not till about 70 mph that this hull becomes unstuck and you feel like your on your way to flying it. This stuck feeling can be worse with extra weight in the boat, so practice getting used it solo first. Be careful into head winds with too much trim as these things can kite, like other streams (the sensation of the bow kind of wafting in the air at your expense).

These boats prefer props with high rake such as round ears (chopper) and hi rake cleavers to help provide bow lift. Be prepared for heavy steering torque, as these hulls are known for it at high engine heights.

This hull gets real sweet at 80+ mph as it feels real locked in and you feel like you’re really flying then

This Hull can also hook real hard and spit you out if not careful. It was at the expense of my hormones and foolishness that I hooked one of these at even as slow as 50 mph .It went up on its side and spit me and a buddy out! Fortunately, the boat righted itself and we were not seriously injured…we did have our pfd’s helmet and kill switches in tact when we went for a swim!.

Again there will be no substitute for proper safe setup and plenty of seat time. Give your self about 3 good months to get aquatinted with it and make sure your hormones don’t get the better of you when taking out passengers.

I hope this helps and please feel free to call on me for more info!

Sincerely,

Anthony SS

[Dan Dillmann]

Pyro, I run my propshaft even with the bottom of the boat on my Vegas XT. I have never tried to raise it any higher. I also have a Land and Sea jackplate. With my 30" chopper I have to use a lot of trim with the jackplate raised all the way up. With two people in the front seats it takes even more trim. Once the boat is flying I can reduce the trim. I think it needs more setback with this prop. I have a 22" pitch 4 blade through hub Mach prop which has no problem lifting the bow at 1/2 or 3/4 trim. So I think the prop does make a difference. My 28" pitch chopper (that runs at 30% slip) does not seem to need as much trim as the 30" chopper.

Anthony, you've been helpful in the past on some hi-perf questions. I know you're a vegas owner, and you were a big influence in my decision to buy this rig. I do get some considerable chinewalk, which I am able to control with the same skills that I developed driving my Baja. As far as engine height goes, will increased height decrease the need for so much positive trim? If not, how should I determine engine height with consideration to the amount of required trim angle? Dan, I ask the same question of you. "Level with the pad" with or without the positive trim? Right now, a good deal of positive trim breaks my hull loose at 64-66 mph. I'm raising the plate up almost halfway, but I haven't looked to see how high the shaft is actually running in relation to the pad. I only weigh 120, so it gets moving in a hurry when I fly solo. You may have read my other posts on Tach/RPM issues. I'm still not sure if my RPM's are in a safe range. I plan to test it tonight with a freq. counter function DMM to verify the dash tach. It is a stock motor, and I don't have the money to get it rebuilt if I fry it, so I have to treat it well. Thanks for the help, and thanks in advance for answering my endless list of questions. -Chad

[Dan Dillmann]

I measure the motor height with the propshaft parallel with the bottom of the boat.

Dan- ...and then trim it beyond that setting once you're at speed?


AnthonySS- What do I do to prevent the nasty hook phenomenon? I don't want to die

-Chad >==FFWD===>>

[Frequent Flyer]

Adding 2" Bob's spacers to your existing 6" setback should do the trick as the more setback you use the more stress you apply to the transom. 7" is the standard for the HydroStream era Vegas XT's (not the new ones made in Canada as they are layed up thick after a few light ones failed).

Prop height (that's centerline of propshaft-PCL) should be 3/4" to 1/2" below the pad.

That 28P chopper should do the trick as well. That rig does not like cleavers. If you cannot obtain the 6500-7000rpm range then a 26P chopper should help.

For you information I used to own a 400lb layup Vegas XT with a 200 2.4L Merc that ran 89.3mph at 7200rpms with a 28P chopper prop, 7" setback and 1/2" PCL height (with a Bob's nose cone). Another local from Long Island ran the same setup on a HydroStream era Vegas XT with a 2.4L bridgeport to 100mph with the same prop and setup.

That rig did better with a tail wind (flew straighter/more level).
Good luck,
Mark

Here we are, back at the RPM issue. This is a STOCK 200. It's supposed to run 5500-6000 WOT. I don't want to blow it up! I don't even know if my tach is on the right setting. I HAVE NO IDEA what rpm I'm actually running. There isn't a single person on this earth who has been able to tell me what setting my medallion tach should be set on, including medallion's own staff. It has 5 settings, and I have had 4 separate answers, and the other setting is where it was when I bought it. I'm about to ****-can the tach and buy a new one that has a manual to tell me how to use it.
Can I get by without adding spacers or anything of that type? Is there a better prop to use that will give me better bow lift. I don't want to add more setback. The transom has not been braced, and I don't want to stress it. The sight of that 400lb.
Merc hanging off the jackplate is already a scary sight.
Hey Dan, what you're telling me, is that you're actually running the shaft ABOVE the pad. You must be, if you're trimming it beyond you're measured setting! Am I going to be risking a blowout by doing it this way?
Thanks again, guys!! -Chad

[Frequent Flyer]

Chad,
I had the same problem with a Medallion Tach in my Vegas XT years ago. Do you have a GPS or access to one? If so, then save your money and simply use a gps speed reading along with a known prop pitch and back calculate your rpms (the equation is on the Internation HydroStream Registry). Try different settings until your tach reading matches the back calculated rpms. Use 12% slip if adjusted 3/4"-1/2" below the pad.

Unless your transom is showing serious stress cracks, the 2" spacers shouldn't be a problem and that boat will benefit from it.

Anytime someone tells you a prop centerline height it is always with the engine as perpendicular to the boat as possible (or with the prop shaft parallel or on the same plane as the bottom of the boat). That is where the engine trim should be at max speed.

The 28P prop should land you in that 5500-6000rpm range you prefer. Speed should be in the mid 70's. The Vegas XT will not be "aired out" at that speed so you shouldn't have to worry about blowover, flightiness or serious blowout.

Anthony, how did you spin out a Vegas XT? I used to fly mine vertical, trimmed up as though I was trailering it and it would just keep on going straight. Never once blew out with that setup.

What about fellow VegasXT owned Dan Dillmann? He is convinced that he was actually running 7200 rpm with a 28" merc chopper at 30% slip. He gets mid to high 70's with that, and claims that he's getting 82 solo with a 30" after a SLOW takeoff and LONG run. He says he's checked his tach with a secondary device. He essentially has the same rig as me. His is a 1987 with a 220 XRi (same as '89 200 XRi) Does one of us have an oddball gearcase?

Again I ask: Should I line up the propshaft 1/2" below the pad with it trimmed the same angle I use at WOT? Considering that my hull digs in and slows down to 65 if I trim it back in to a neutral setting... Will jackplate height eliminate the need for so much positive trim?

[Techno]

Trim and height are two different things. The prop shaft at any given height is always at no trim, neutral. It's a reference number kind of thing. Otherwise you would have a different height at each trim degree. In fact it's impossible to set the height with any trim, Where on the shaft are you going to refence from.

Somehow with a jack gauge or a piece of tape to mark the height you want to have your OB at, some specific height, put it there THEN play with the trim.

At zero trim ( shaft is parralel with the straight edge) put a straight edge on the bottom and set the center of the prop shaft at 1/2" below the pad, mark it somehow so you can find it when you go out. I have a manual plate so I metal stamped the values right on the side. Another way is level the hull with the trailer jack then set the prop shaft level, then set the height.
Your using your thrust(engine power) to lift the bow of the boat. You want to run with no trim and use all your power for speed. You can't do this though because of what the others have said, setback. Moving the OB back will lift the bow without the trim, until it's moved so far back that you would need neg. trim to hold it down.

Another way of putting ALL of this is to look at your rooster tail(or have someone else look or tape it). If it's real high then thats were your power is going. If it's long and low then it's doing it's best.

[AnthonySS]

Dear CHAD,

Thanks for the kind words. I actually have never owned a VEGAS, however I have spent a lot time playing with setup on them and driving them. I have to thank my good PBCC buddies Mark Hettwer and Mike DiPietro (whose boat is know owned by AQUAholic) for allowing me to play with their VEGAS’.

Here is the second of two Vegas’ my buddy Marked owned. It has since been sold (last summer)and I am unaware of the new owner

http://www.pbcc.on.ca/images/0003.jpg

Marks boat was truly unique and you can read about in on HydroStream .Org. Pick link below.

http://www.hydrostream.org/SpotlightArchive/Hettwer.htm

Increasing the engine height will not reduce the amount of trim needed to fly the hull. As mentioned I would set prop-shaft centerline to level with pad. This has proven to best for overall performance on Vegas I have helped setup, plus it is hard to set them any higher with most jack-plates and the standard transom.

Engine Height should be determined by leveling the pad with a spirit level, and then using the same level to level the motor by placing the level on the anti-ventilation plate. Take a grease pencil or white pencil crayon and try to mark the P/S C/L on the side of the case as best as possible

When the pad and the anti-ventilation plate are on level, Then take a strait edge about 4-6’ long, and place it squarely on the pad and extend it back to the gearcase. Measure the distance from your straight edge to line on the gear case to determine where your P/S C/L is in relation to the bottom of the pad.

Get a friend to help you as this really helps with adjustments.

Increasing the engine height will not reduce the amount of trim needed to fly the hull. As mentioned I would set prop-shaft centerline to level with pad. This has proven to bets for overall performance, plus it is hard to set them any higher with most jack-plates and the standard transom.

You definitely, have to trim out to get the Vegas to work. It has to get up on the pad to and fly. That is what it is designed to do. However, I realize it does take time to work up to that technique. Often our rig can scare us before we find that sweet spot.

The chine Walk will go away with better setup and seat time. By raising the motor you will shorten the axis, the boat has to rock over on. In other words, the distance from the bottom of the pad to prop shaft c/l will shorten up. Also, make sure the steering is adjusted to have very little play. This will assist with chopping the steering when the boat wants to start walking.

Chopping the steering means, literally that…take quick short strokes back and forth on the wheel turning the wheel opposite to the direction of the rock. It really works and gives you a work-out to boot.

Check out the link below on an article I wrote about crashing out a VEGAS. Don’t be scared by it , just be aware that it can happen a low speeds (about 50) with really tight turns

http://www.pbcc.on.ca/main/Lapse.html

Sincerely,

AnthonySS

Tonight I'll take the Hstream out for a spin, and I'll get to work on the motor height issue. I have a hydraulic plate with an indicator, so I can use that to reference plate position. I'm only slightly concerned with top end above 75. I use the boat for "pleasure" (impressing friends, river cruising, outing w/ girlfriend, etc.) but I would like to tap into its potential when these bad-asses with bass boats try to f&%# with me. I'll take note of the proper position on the indicator gauge.

Hey flyer, Dan says he's getting 30% slip. Am I going to be able to back-calculate rpm's based on the wide range of reported slip values??

I have the number for the prop, by the way. It reads:
QUICKSILVER 48 13372 A5 28P

Is this a Merc V6 28" chopper? Dan thinks it may be a weirdo prop...


[Edited by pyro on 05-02-2001 at 09:43 AM]

[daytona]

My 21 daytona and the hydrostreams I see in your pics do not run flat but with a 3 to 4 degree bow up angle for air lift. Therefore a coresponding up trim angle on the motor is required to keep the gearcase moving parallel thru the water. rick

I realize that I don't have enough setbak, because I have to trim mine above such a setting to maintain bow lift. Maybe if I get it flying a little faster with the plate higher before I try to trim back in, I'll have better luck. I haven't been running the plate high enough to fully benefit top end. -Chad the pyromaniac

[AlaskaStreamin]

Chad,

I have several tach's and the dash wiring harness that plugs into the control box. If you want, I will wire up a tach to a spare harness and send to you to try. Just plug it in and read it. Then you can plug in your harness and compare readings. All you'll need to pay is the postage both ways.

I think a second person in the boat could swap plug-in's while running at a set speed. That way you can compare tach readings without stopping. Another way is to wire it in parellel with your other tach. I would check with someone more knowledgable if this way would mess up the signal or put too big of a load on the rectifier.

As far as your trim problem goes, The motor should be level at speed to give the best performance. With too much positive trim, the gear case is running through the water not parellel which creates turbulance. At high speeds this can cause blowout.

Randy Reinke (AQUAholic) has a Vegas and just made a transom tie bar because he was seeing flexing. Shoot him an e-mail and he can send you pictures of what he did. Hope this helps a little. Ron Pratt (ronp@cityofsitka.com)