1/6 Hydroplane stuffing box
 

This is my first hydroplane. Need some help on the stuffing box. Pic shows how I think it should be. Full length tube all the way to strut. Or should I just have a partial tube and just run the back part of the cable to the strut? Tube is 5/16. Ran the drive cable through the tube pictured and it drags too much. Maybe I have to redrill the motor mount and decrease the stuffing tube angle?http://www.rcuniverse.com/forum/atta...mentid=2206804

That bend in the tube is your issue. You need to do a slow bend, not a sharp one like in your picture. If that's a hydro you're showing, you need to change out that strut for one without a skeg as that will adversely affect your steering

I figured the bend was too sharp. I decreased the angle of the motor so stuffing tube will have a less of a bend. Should I bush done just the front of the stuffing box to where it is closer to 1/4" or just stay with the 5/16 all the way? I will either get another strut without skeg or just cut the skeg off. Thanks

Before I answer that, what size flex cable are you using? This will seriously affect my answer

1/4" flex cable I bought from gizmomotors.

A 5/16 tube is almost too tight for a 1/4 cable. That's why there is so much drag at that bend, you have the cable rubbing on the inside of the bend and on both sides of the bend since the cable can't bend that sharply. You might want to move up to a 11/32 or a 3/8 to give the cable more room

Since I decreased the angle of the motor and made a nice large bend in the tube it turns real smooth now. I used the same size tube and flex cable for a 1/4 tunnel hull and a Expresscraft GTX. I will post some pics tomorrow.

agree with Hydro Junkie, the brass shft log is abit to small in internal diameter, with a 1/4 inch shaft you only have 1/32 nd of an inch around the shaft for lubrication, thats not enough. if you can remove the tube log and fit a 3/8 inch I.D. tube this will give 1/16 th all round the shaft.
also cut the fin off the strut and bring the strut down so its closer to the ski plate as this ski is there for lifting the transom .

There is two sizes of 5/16" tubing 5/16" x .014 x 36" is K&S # 1151 ..... This is the tubing you want ... and .....there is 5/16" x .029 x 36" (K&S 9211) - this you DO NOT want as it's (.024 thick wall) too tight ...........1/4" Cable uses 5/16" tube - if you use anything else it will destroy it self rather quickly - you do not want slop in the tube -- you want it snug fit ............Your issue (unless you used wrong thickness tube) is the real sharp bend --- the bend should be a gradual bend ------- yours looks like it will kink the cable -- will also wear out very quick at that point.........................
Do not run anything but 5/16" or you will be replacing it soon - fix the bend (kink) ....................When you bend your tube - put a cable inside it and make a gradual bend not a 'kink ............. 5/16" (.014) tube is for 1/4" Cables ............................. you should run small piece of 11/32" through the hull (gets glassed in) then the 5/16" runs thru it --- then if you have to change tube the 11/32" stays in boat and the new 5/16" will just slide through it. If you just glass the 5/16" tube then if you have to replace you have to cut out.. If 11/32" is glassed in hull --- then just take out old replace with new.

What Randy said. Use .014" wall 5/16" tube and fix the bend. Don't glass that in whatever you do. As stated it must go through 11/32" sleeve through bottom. The tube is locked in the strut so to enable adjustment it must be able to move in and out at the bottom.

Stuffing tube
 

OK here it is. 5/16 tube with .014 wall. Nice easy bend. No dragging. Used a 4mm carbon fiber plate to reinforce stuffing tube in hull. I am waiting on turn fin so I can install that before installing fuel tank. I am moving back to Dallas very soon so will maiden the boat there and if anything needs tweaking it will be in Dallas. http://www.rcuniverse.com/forum/atta...mentid=2208197http://www.rcuniverse.com/forum/atta...mentid=2208198http://www.rcuniverse.com/forum/atta...mentid=2208199http://www.rcuniverse.com/forum/atta...mentid=2208200http://www.rcuniverse.com/forum/atta...mentid=2208201

looks good . the shaft now has a nicer bend for less drag but make sure you leave atleast 1/4 to 3/8th inch gap between the props drive dog and the rear of strut, the flex shaft compresses at rpms under load and it will bind up if the gap is too small. also with the wrap to center manifold / pipe combo, try for 13 inches from the exhaust manifold face to the weld join in middle of pipe, use a piece of wire and bend it to the same shape as pipe manifold to pipe , should look like a question mark in shape.

As mentioned you have a problem.
Zero drive dog to strut clearance. That can't be that way and last very long. It can't make contact with strut or cable will be destroyed. The only fix now other than buy a new cable is to cut the stub off the back of the strut or redrill the brackets and bring strut blade closer to transom. This will give you the minimum 5/16" or 3/8" clearance gap it must have.

Measuring Pipe https://youtu.be/ysUTCyOYBTI

just what i said in words. you love those pics randy andy. lol

Yes I do appreciate you watching my videos and then 'trying' to put it in words. LOL

Ah Poor Jonney - isn't this a fun hobby ? The "No pictures" says it all .............

LMAO still

Engine is a gizmomotors 29.5 pro race. Gizmo rates it at 7.2hp. Tuned pipe is gizmos latest. 2 props I have to try out first is a ABC M90 SAW. and a Prop Shop 7024/3 chopper prop

mistycreek. its funny how i answered the question about pipe length before you posted up you favourate pic. funny that isn,t it . thought you were abit backwards in coming forward. lol

henschel, as i mentioned if you get the pipe length from the exhaust manifold to where it bolts to cylinder head face and measure around to a total of 13 to 14 inches even you will be very close with the correct length for this system. take note those wrap to center manifolds are not as good for power as the normal 90 degree bend types so to get the length required [ 13 to 14 inches ] alot of the straight section of manifold will be cut off but only do this cutting when you know the pipe is coming on when and where you want it too. once cut thats it. there you go misty you learn something more. lol forgot to mention those props , don,t start off to big for oval , propshop 6719 x 3 is good .

With a wrap to center like that one you will just cut it as short as it will go.

Identify the hull
 

Dose anyone know who makes this hull or where I can find info about it??

I'd opt for a better one as the CG will be too far back in that hull. It needs a lot of forward weight to perform properly. Note where hte engine is in relationship to the sponsons.https://cimg4.ibsrv.net/gimg/www.rcu...72238dd731.jpg

I bought it off that guy last month just wanted to find out more info in the hull. I thought about cutting the front cockpit off and moving the radio box up front and buy or build a new full length cowling.
That should help get some weight off the tail