boat getting loose???hard to drive.

[stratos200vt]

I got a 200vt stratos and I been working with a few different props and one prop that I got to run good on my boat. Well riding down the river yesterday about 70 mph with this prop the back of the boat kicked side ways. Somebody said it's like a prop blow out or blow over or something of that nature. I am new to this kinda of stuff. It was kinda hard to hold on to and had to drive it purdy hard to maintain control. Does anybody know what does this and how to fix it? Thanks.

[oceantraveler]

What you experianced is BLO OUT my friend... Do a search it has been discussed many many time on here!
What you may want to do is Nose cone are a sportmaster case Lw pu and all the goodies.There is a ring also available. :thumbsup:

[stratos200vt]

Thanks I have to try to look it up on here. It feels pretty dangerous?

[D.B.S]

It is!!!!!!!!

[WATERWINGS]

The first time it happened to me, I thought I was gonna go swimmin !

I went back to the dock at about 25 MPH:eek:

[oceantraveler]

Its as Dangerous as being ejected out of a fighter jet. The water is like concrete at 80 mph.consider your self lucky usaly they hook and throw ya out!:eek::leaving:
Thanks I have to try to look it up on here. It feels pretty dangerous?

[stratos200vt]

I did the same thing I slowed to about 40mph the rest of the day. I didnt know what happend so I am lucky. I would hate to hit the water running that fast. I hit it before riding a jet ski about 50mph And it hurt bad. So I couldnt imagine running 70mph and hitting the water.

[pyro]

Too much motor height, too much trim, lack of a nosecone (or major flaws in the gearcase running surface or cone fairing), lack of a torque tab and resulting crabbing gearcase angle, bent skeg, or a broken skeg, can all contribute to a blowout condition.

[whipper]

Are you versed in controling a pad vee on the pad? If not and you are chine walking this will contribute to blowout. If the hull isnt straight and its rocking side to side even with the right amout of trim you could blow out. Try less trim and when your going 65 pup it up once or twice. When you hit 70 is the hull rocking side to side? If it is your prop might be rocking out of the water also. At those speeds you need calm water and a steady boat. The turbulents caused buy the hull not taking a firm stance will creat pockets beside your gear case and your prop will bite air. And so might you.:D

[GPRACING]

Its a tunnel vee.I have one except its a 180VT.If I had to guess Id say you were over trimmed.These boats dont like alot of trim.What motor/prop/engine height are you running??

[whipper]

Ohh I guess thats what VT means Vee Tunnel. Doh!:D In that case I agree also over trimmed. Might be to high on the jack or even some kind of obstuction under the hull? Probably not but worth checking for anyway. If theres a good nick some were like your gearcase or the aft portion of the pad that can couse water disruption and air bubbles hitting your prop.

[WILDMAN]

May be blowout, but most likely if it kicked to the right, it's having the motor too high or trimming too high. It's called Prop-walk. It's when the prop is over halfway out of the water and the prop paddle-wheels the boat sideways. Lowering the motor or less trim will stop it. I'd think that 70 mph is too low a speed to create a blowout condition. In a blowout, the nose will drop and the boat can hook. It does'nt sound like that's the problem.

[Ted Stryker]

May be blowout, but most likely if it kicked to the right, it's having the motor too high or trimming too high. It's called Prop-walk. It's when the prop is over halfway out of the water and the prop paddle-wheels the boat sideways. Lowering the motor or less trim will stop it. I'd think that 70 mph is too low a speed to create a blowout condition. In a blowout, the nose will drop and the boat can hook. It does'nt sound like that's the problem.

:iagree:

[brockshydro]

this is my brother in law he put a depth finder on the boat and the transducer is in front of the motor could that cause it.

[WATERWINGS]

AH HA !!!!

YES, it could if it is anywhere near the path of the gearcase.

Speedo pickups, depth finders, and stuff like that should be as far away from the motor as possible.

That may not be the total answer to the problem, but it sure is the first one I would look at.

[stratos200vt]

I have the jackplate all the way down in the water. No LWP. and with the other props it want to it . Just a 4 blade. To far in water to be prop walking. Like my brother in law said on the post before me. I put a depth finder on. The transdoser is right by the drain hole in front of the motor. So it may be that.?Whatcha think?

[bobthebuilder]

Motor too deep I think. A boat will drive really bad at high speeds if the motor is too deep... Center of prop shaft should be only 3 inches or less below bottom of boat, But you didnt give enough info about how it is doing. Synptoms??? Is it jerking when yuo let off it? Mounts too soft? Too much play in steering system? Lots of these things can happen to make it drive mean.......

[stratos200vt]

driving straight and just one major jerk. Pulled backend of boat around. Kinda hard to say. Motor could be to low like you saying because Its actually sitting lower than it would if it was on the transom by itself. I waiting on the LWP so I can raise It on up out the water.

[Wizard]

First move that transducer way to the side. It should not be anywhere near the centerline of the hull. It will cause ventilation in the water going to the gearcase which will cause the prop to slip.

I also agree that your engine is too low and your trimming too high. The VT should be able to carry itself with little trim. That's what air trappers do. Because your gearcase is too low you need more trim to get the rpms up. By overtrimming your forcing the stern down which will increase chinewalk. Your also moving the prop closer to the surface but at a greater angle thereby increasing slip and effeciency. I think the combination of too much trim and too low caused your blowout.

Properly measure your engine height. Your propshaft should be 2" or less below the lowermost center pad. Your going too slow to need a nose cone and you should still have decent pressure while 2" under. Use less trim and let the air natually lift the hull through the tunnels. Check your rpms and adjust accordingly with prop pitch. What prop where your running by the way? What rpm?

[bobthebuilder]

You can jack the motor pretty high without a LWP and still get enough water to the motor. Watch the water pressuer guage. If you dont have one on it then get one on there for sure and keep a close eye on it especially when first setting the boat up. I agree with everything Wizard is telling you. Starting with moving the transducer! Also different props carry the bow naturally without a lot of trim. If you got to trim it a lot then you probably need a different prop. It sounds like it was blow out situation to me too but sometimes it will do that when you start backing off the throttle. That means you need some solid mounts or a steering Y brace. When building a motor for high performance use soild mounts. If it is already all together you can sometimes find a Y brace. Bob's machine might still have some. Years ago that was the ticket before the solid mounts where popular. Oh yes another trick is put some duck tape over the top 2 holes on both sides of LU so it don't suck air in there until you get the LWP on it. I would start with the center of the prop shaft about 2 to 3 inches below the pad. If it is too high or too low then adjust from there. 2 inches was too high for my Ranger Bass boat. I am at 2 1/2 and it performs perfectly. But I am running a LWP on a 2.4 200. Hope this helps. Let us know how it works out for ya.

Wizard-- thats a tough looking little boat there! SHARP!

[stratos200vt]

I was running a 25 pitch prop. At the most 5300 rpms. But that is with the jack plate lowered all the way in the water. I goin to raise it before saturday and try a few different props and see what happens. Wizard you got a heck of a boat there. What speeds you running with that?

[whipper]

Trophys like 1/4 below the pad.:thumbsup: No more than 1/2 inch.

[scc82]

May be blowout, but most likely if it kicked to the right, it's having the motor too high or trimming too high. It's called Prop-walk. It's when the prop is over halfway out of the water and the prop paddle-wheels the boat sideways. Lowering the motor or less trim will stop it. I'd think that 70 mph is too low a speed to create a blowout condition. In a blowout, the nose will drop and the boat can hook. It does'nt sound like that's the problem.
:iagree::iagree::iagree: for sure prop walk, lower your motor trim

[scc82]

motor is not to low, it is the transducer that is interupting the water and interducing air to the prop causing the prop to blow out and them prop walk.
your are never not going fast enough for low water p/u, all it will do is help the whole rig run faster, cleaner, easier, swallower and more effecient. cant beat that its like free hp

[Reaction19]

motor is not to low, it is the transducer that is interupting the water and interducing air to the prop causing the prop to blow out and them prop walk.
your are never not going fast enough for low water p/u, all it will do is help the whole rig run faster, cleaner, easier, swallower and more effecient. cant beat that its like free hp




WOW!!!!!!!!!!!!!!!!!!!:eek:

[scc82]

WOW!!!!!!!!!!!!!!!!!!!:eek:
see you learn something new every day.
tune in later for your next lesson:rolleyes:

[stratos200vt]

Thanks for all the lessons.lol. I up the motor on the jack plate and it's about 2 inchs below the pad. I put some kind of 28 pitch chopper prop worked by DAH. It ran 75 mph gps and only running 5200 rpms. Liquifly said on these type boats I prob be about 2 inchs above pad. Thats his guess. I think I can pickup a good bit of speed. Only the 4 blade prop got my boat loose. So I guessing it was just the prop.

[scc82]

sounds good. 75 is not bad at all
good luck

[GPRACING]

You need to put that gas tank back in the rear.Just my 02 cents:cool:

[stratos200vt]

I had it in rear and in front it didnt change the speeds any. I actually think it helps coming out the hole but we'll see how it affects the boat after I get the setup right. You brining yours out this weekend?