Paging ((((((HBJET))))))

[matt1]

I was wandering what you know about inside lifting strakes running all the way to the back of the boat.I just discovered mine go all the back.Boat is a'83 Taylor SJ with a stock(250HP) SBC je pumpW/place diverter and A impeller(Jack said it looked like a B though),top speed was 60(GPS)@4400 RPM's.I never really thought the boat felt to bad untill I recently installed A(500HP@6500RPM's dynoded)now the boat is very unstabal at high speeds and when you let off the throtle it gets really squrilly then dives to the right real hard.I know Im not seeing the true 500HP since the eng.will only turn 5000RPM's so I only think Im going about five MPH faster.Any info would be greatly appreticated.I also noticed that on Taylormans '76 SJ that his inside lifting strakes dont they stop befor the intake opening also JE pump.Here's a shot of the rear of my boat. http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-001F5.JPG :confused:

[HBjet]

I don't know anything about your boat. How long is it?
Anyways, the problem your having with the boat being very unstable at high speed is due to those inside strakes. The faster you go, more of the boat is out of the water. When you have those inside strakes all the way to the transom the hull wants to ride on those strakes wich is a very little area for the whole boat to ride on. Like I said before, I don't know anything about your hull. So, if the mfg designed that hull like that, I would have to assume that hull wasn't designed to run that fast.
If you wanted to spend some money, I'm sure you could have them shortend. I would also suggest not running your boat at the speeds where the hull is un-stable.
I hope this helps you some.
HBjet
[ January 01, 2003, 07:56 PM: Message edited by: HBjet ]

[ChetCapoli]

What i want to know is why would you be asking HBjet a question like that? I'd be willing to bet you have some hook in your hull and it's plowing the nose. Any shots from ground level of the back of the boat? Interesting a factory boat has strakes all the way back.
CHET
Any word on where my boat came from HB??Just curious
[ January 01, 2003, 09:18 PM: Message edited by: ChetCapoli ]

[Jrocket]

Oh shit here we go again...LOL :D

[77charger]

grabbin the popcorn. :) :) :) :D

[matt1]

The boat is 18'.I adjusted the ride plate all the way up which let it ride a littel higher than before I've only had the boat for 5 months and haven't been able to play that much.I have to go get the digital camera at work to take pics of the bottom thurs.is out of the question b/c of work and possibly going out of town this weekend.The reason I asked you HB is b/c Ive never heard of the lifting strake issue till you told Chet that was a nono.Yeah Ive been following the saga ever since it started.So Chet don,t turn this into a pissing contest and from what Ive been reading HB knows his shit.Oh and don't worry about me running at high speeds anymore since this issue has caused me to CRASH burningm no major damage to boat but put a nice hole in the top deck.I also have a milkshake problem that I need to solve and one of my logs is at the shop to have a crack repared.Heres the only running pic I have of the boat this shot was taken in my back yard sorry the qaulity sucks. http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/Img22.JPG

[HBjet]

If your boat is very unstable at high speed, hook in the hull would not cause that. Like Chet said, if there was hook in your hull (enough to be a major problem) at high speeds your hull would be plowing through the water, which would mean a lot of your boat would be in contact with the water, making your boat slow, but stable!
Since your boat is not stable, you can eliminate the assumption of hook being your problem. You can play with the ride plate by moving it down a little to see if that helps any. I would see if you can talk to other people with the same boat as yours and see what they are doing. More photos of the bottom would be great and when you have the time, please post them up.
BTW, it didn't surprise me one bit Chet posted right after me.
HBjet

[miller19j]

What are the bolt holes in the picture from? It looks like there may have been a set of trim tabs on there once.
http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-001F5.JPG

[cyclone]

judging by the pic, it looks like his hull doesn't ride that wet. The hooking to the right thing when he lets off the gas sounds to me like the boat is bow steering. My old Rogers did the same thing. It basically wasn't too safe over 70mph when you let off the gas. I had to gingerly slow down to keep it from hooking to one side.

[TE081]

Sounds like a keel problem to me. You might have to change it! Call Tom Papp at http://tompappracing.com A client of his Phil had an advenger that did the same thing. ask him what Phil did to fix it!That advenger is a rocket! matt1:
I was wandering what you know about inside lifting strakes running all the way to the back of the boat.I just discovered mine go all the back.Boat is a'83 Taylor SJ with a stock(250HP) SBC je pumpW/place diverter and A impeller(Jack said it looked like a B though),top speed was 60(GPS)@4400 RPM's.I never really thought the boat felt to bad untill I recently installed A(500HP@6500RPM's dynoded)now the boat is very unstabal at high speeds and when you let off the throtle it gets really squrilly then dives to the right real hard.I know Im not seeing the true 500HP since the eng.will only turn 5000RPM's so I only think Im going about five MPH faster.Any info would be greatly appreticated.I also noticed that on Taylormans '76 SJ that his inside lifting strakes dont they stop befor the intake opening also JE pump.Here's a shot of the rear of my boat. http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-001F5.JPG :confused:

[HBjet]

RD, I still don't think it's a hook issue.
Miller, good eye. After looking again, there may have been some sort of trim tabs on there to make the boat more stable and like Cyclone mentioned, this boat might have not been designed for very high speeds.
HBjet

[HBjet]

TE081:
Phil had an advenger that did the same thing. ask him what Phil did to fix it!That advenger is a rocket!That's the ticket right there. Someone who had the same problem and found a solution that works. I would try to get in touch with either Tom Papp or Phil and when you know what to do, please let us know what that is.
HBjet

[miller19j]

RiverDave:
HBjet:
RD, I still don't think it's a hook issue.
Miller, good eye. After looking again, there may have been some sort of trim tabs on there to make the boat more stable and like Cyclone mentioned, this boat might have not been designed for very high speeds.
HBjet To be honest I don't think it is either.. I was just giving ya some shit for your "blanket" statement. wink :D
RD Can someone please moderate this “post whore”? :D

[Bense468]

basically wasn't too safe over 70mph when you let off the gasYou should not be letting off the gas like that in a jet boat period without a pop off. Leave that for the flats... that is what gets you hurt in a jet.

[Bense468]

Well if it was that critical that you have to let off in a situation, then yeah you can do it but you VERY well can be pitched. If that is what you need to do to keep someone else from getting hurt then so be it. If you can drive around the situation I would suggest doing that. Remember when you just let off you have no steering. Also the impellar just slowed way down and where does all that water have to go that is being loaded in the pump? No where Right? So it lifts the back of the boat and Marbles. It can put you in a flat spin and when you catch the edge watch out. It could or will put you on your head.
As far as OP6. I am sure I will probably go. Not sure if I am taking my boat. I might Just might have it sold by then. It is not up right now. But I have some other plans. If you are curious I will e-mail you. More then likly I will be with friends with boats or I can take my dads, it is in havasu. We also have a fat place right at the bridge. So we will see won't we.

[HBjet]

RiverDave:
So in the event that you have to slow down quickly your just F***** or what?What do you do in an I/O? Pull the throttle to neutral and watch a few passangers fly over the open bow? What Bense means is when you need to slow down, gradually let off the gas so you still maintain control of the boat. The boat will still slow down fast enough. When your at 35-40mph in a jet, you can lift off the gas the boat will slow no problem. It's the higher speeds that are not good because your pump is used to pushing a certain amount of water through it and when the RPM's drop where is that water going to go if the impeller isn't nearly turning as fast as it was?
HBjet
[ January 02, 2003, 03:12 PM: Message edited by: HBjet ]

[Bense468]

Right on Dave. Thanks for the offer

[MikeF]

Bow steering and letting off the throttle too quickly is something that needs to be avoided in a jet (moreso a V than a tunnel). Especially at higher speeds!
Unlike a V-drive, sterndrive or outboard, there is nothing in the water hanging off the back of the boat which would aid in the slowing of the boat in a "straight" fashion.
Lets say a jetboat weighs 2200#'s. At least 1000 of it is in the engine, jetdrive and fuel tanks. The hull and driver is the other 1200. If the hull is 1000#s, and you divide that in half (reference only) you have 500#s for the front and 500 for the rear.
Where is all the weight? At the rear of the boat. 1500+#'s!
When you let off the throttle too quickly, the bow settles down and starts to adhere to the water. If it starts to stick very well (bow steer or letting off the throttle too quickly at too high a speed), it will now pivot nearer to the forward half of the hull and with all that weight in the back, And if it starts to turn, It will come around very quickly! eek!
It's just one of the things that MUST be learned when driving a V bottom jet that will reach speeds higher than 70+mph. Just try not to learn it the hard way by being tossed or possibly sinking your ride. boxed

[matt1]

The holes were not for trim tabs most Taylor boats came w/a pump cover like this one http://www.hi-techperformance.com/images/74_SS_Taylor_Brown_803.jpg The holes just had silicone in them I just ran out of bolts for the two on the left.I also don't know what the keel is can someone show me.I got the bottom pics taken but something is wrong w/ the meadia center.

[matt1]

Heres some bottom pics http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-004F6.JPG This one is with the trailer tong on the ground http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-004F6.JPG So are these http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-002F6.JPG http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-001F7.JPG This one is with the trailer level http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-006F3.JPG And one of 500HP eng. http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-005F5.JPG
[ January 05, 2003, 08:58 PM: Message edited by: matt1 ]

[ChetCapoli]

hey matt1
Did you ever put a straightedge on those strakes and bottom to see if in fact the hull has some hook to it? I know the "no-no" man is who you would ask in a situation like this but could you humor me? Also, do you have a pic of the back of the boat so we can see the bottom from one end to the other? Reason i ask ya is because with that insert pump nothing really should be hanging below keel(those from what i understand are built in above keel) which would cause the symptoms you describe. thanks
CHET
[ January 06, 2003, 07:01 AM: Message edited by: ChetCapoli ]

[matt1]

No I never did put a straight edge under there.Still don't know what the keel is.

[Oldsquirt]

Matt, if you were to draw a line from the tip of the bow along the bottom of the boat to the bottom center of transom, that would be the keel, or keel line. On a v-hull it is real easy to see as it is the point of the V running the length of the hull.

[matt1]

Ok thanks now I understand.

[flat broke]

HBjet:
If your boat is very unstable at high speed, hook in the hull would not cause that. Like Chet said, if there was hook in your hull (enough to be a major problem) at high speeds your hull would be plowing through the water, which would mean a lot of your boat would be in contact with the water, making your boat slow, but stable!
Since your boat is not stable, you can eliminate the assumption of hook being your problem. HBjet Randy,
I'm going to have to disagree here. Depending on how much hook he has and what the rest of his hull profile looks like, he could well be inducing bow steer with the hook in the rear of the boat. The hook causes lift at the transom and drives the nose down as you already know. What isn't known is where the nose is contacting the water. If the hook is excessive enough to push the steeper entry portion of the V down, the boat will want to hook and dart from interacting with the varied shape of the water's surface when going faster (a relative term between different boats as fast for Randy is 80 and fast for Matt might be 60). This isn't just theory either, I have been in a boat at 50mph that induced such nasty bowsteer upon itself that the slightest amount of steering input promoted a very aggressive reaction from the hull.
When addressing handling problems you should always start by straight edging the bottom to see where you stand. I'm by no means saying that your other suggestions are good, just pointing out that hook could very well be inducing the situation Matt is describing.
Talk to you later,
Chris
[ January 06, 2003, 09:51 AM: Message edited by: flat broke ]

[matt1]

Thanks for all the info you guys are great here is some more bottom pics. http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-001F8.JPG http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-002F7.JPG http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-007F.JPG http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-008F1.JPG
[ January 06, 2003, 10:06 AM: Message edited by: matt1 ]

[HBjet]

Flat Broke, I see what you mean. Hook could cause it, but inside lifting strakes extending to the rear of the hull will defiantly cause it. Since we know his inside strakes do extend to the rear and we do not know if there is hook, I'm still saying the stakes are the problem.
Another owner of the same type of boat even had the bottom changed (shortening the inside strakes 2-3 feet from the transom) and his problem went away. From riding on the very center and back of the boat, the boat will get out of control. When you let off the gas, the hull is going to drop back into the water, causing the boat to get wild again.
I see what you mean about the hook, but the apparent problem to me is the strakes!
HBjet
[ January 06, 2003, 10:36 AM: Message edited by: HBjet ]

[DogHouse]

My thoughts, for what they're worth:
From looking at the pics, it looks to me like the boat does ride wet. Even with the diverter all the way up, the boat is totally level. Granted, the water break is fairly far back on the boat in the photo, but with the boat sitting so level it wouldn't take much of a bump in the water to make the nose dig in and start to cause some "bow steer". Also look at the ride plate angle, it's almost level with the keel of the boat. I thought they were usually supposed to be up about four degrees so that the boat can sit with a slightly nose-up attitude at speed. Another factor is the lack of a droop snoot, so the thrust line is fairly high in the boat. To me it all adds up to bow steer and a squirrely ride at high speed. Comments? (be kind, ha ha! wink )
-brian

[miller19j]

HBjet:
Flat Broke, I see what you mean. Hook could cause it, but inside lifting strakes extending to the rear of the hull will defiantly cause it. Since we know his inside strakes do extend to the rear and we do not know if there is hook, I'm still saying the stakes are the problem.
HBjet I am a little confused with this HB, my inside strakes extend all the way back on my boat. Now my boat is not really fast but my same hull broke the Jet Boat speed record in the late seventies and according to Jim Miller it is quite stable at high speeds.
So what is the deal with the Strakes?

[Jordy]

miller19j:
So what is the deal with the Strakes? I was just thinking the same thing:
http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/DSC00329.JPG
My boat is really stable without any of the nasty habits that have been brought up here. Could there be more too it, like motor placement and obviously hook, perhaps more so than thought before???

[Blown 472]

I too am cornfused, I have the strakes all the way to the back, the only time the boat moves around or does anything stupid is when I get out of the throttle too quick and it backs water up, other wise it rides fine.

[Jordy]

My Schiada doesn't have them, and as I recall it was much looser in the water...
http://free.***boat.net/gallery/Reader_Rides/Jet_Boats/DSC002362.JPG
[ January 06, 2003, 01:12 PM: Message edited by: jordanpaulk ]

[78Eliminator]

jordanpaulk:
My Schiada doesn't have them, and as I recall it was much looser in the water...
Man, no wonder you're not selling it. Not much of a sales pitch! Why don't you just give it to me?

[Blown 472]

Then you take your place as big pimpin?

[miller19j]

78Eliminator:
jordanpaulk:
My Schiada doesn't have them, and as I recall it was much looser in the water...
Man, no wonder you're not selling it. Not much of a sales pitch! Why don't you just give it to me? I think Lindsey already tried that approach. :D

[Jordy]

78Eliminator:
Man, no wonder you're not selling it. Not much of a sales pitch! I'm comparing it to my yellow boat that does have the strakes. It was possible to slide the Schiada, granted you had to work at it, but it never did anything dangerous, even if you dumped the throttle from wide open, and the yellow boat doesn't either, but it seems to hug the water a little more, but doesn't have any of the bad habits either, even from wide open with a quick shut down. I'm just curious to know the difference as I own and have driven these two with entirely different bottom designs. :D
Why don't you just give it to me? I'll get right on that. Just give me $3,000.00 and it's yours. :D

[HBjet]

You guys.....this is what I'm talking about.
Here
http://free.***boat.net/ubb/Avatars/Forum_Graphic_Depot/MVC-002F71.JPG
Not Here
http://free.***boat.net/ubb/Avatars/Forum_Graphic_Depot/DSC003291.JPG
Without know much about your Hull Jordy or Miller, take a look under it and I'm willing to bet 12packs that you both have another pair of inside stakes that stop 2-3 feet short from the transom.
HBjet

[miller19j]

HBjet:
Without know much about your Hull Jordy or Miller, take a look under it and I'm willing to bet 12packs that you both have another pair of inside stakes that stop 2-3 feet short from the transom.
HBjet You may be right I will check mine tonight.

[Beautiful Noise]

http://free.***boat.net/ubb/Avatars/Forum_Graphic_Depot/DSC003291.JPG
I didn't recognize Jordy's Boat with out the Velocity Stack :)
Steve

[ChetCapoli]

matt1
http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-002F7.JPG[/IMG] http://free.***boat.net/ubb/Avatars/Reader_Rides/Jet_Boats/MVC-007F.JPG [IMG][/QB]Now if that pics serves me well..i'd say it is the bottom set of strakes and they have one hell of a hook. Definately make that boat dance all over the water. Matt, can you take the same picture except back a little farther so we can see the transom in that picture at that level??
CHET
[ January 06, 2003, 04:25 PM: Message edited by: ChetCapoli ]

[HBjet]

Chet, no matter how far back the photo is taken, you won't be able to tell without taking a straight edge to it.
HBjet
[ January 06, 2003, 07:08 PM: Message edited by: HBjet ]