50" Hydro Build

[Rumdog]

Wait... your running no gap between the drive dog and strut?

[Make-a-Wake]

I ran it with a gap............put the sheer push of the prop bent the strut in and up............there's only one bolt in it...............thats what i was wondering. How can a strut stay in place with only one bolt and such power. I have one bolt on my elam strut but there's a solid stuffing tube, its never moved. The stock setup is really not a sturdy one................it'll be fixed though

[martno1fan]

I ran my zippkits rockett with a strut with one bolt ,a rudder with one bolt too,6.5 hp zenoah and she clocked 69 mph never broke a flex or snapped anything.My advice is ditch the teflon liners theyre poop .The hull needs to balance at no more than 1-1 /2" behind the sponsons if you ask me,you also need a prop with lots of lift(no rounded tips),i ran a 6717/3 boat ran 60 all day in most conditions.Id love to build an electric hydro might need to have a go with one of my Comets theyre 50" also.
Mart

http://www.youtube.com/user/martno1fan#p/u/10/wVGBWC_3MuY

[keithbradley]

So...Im trying to figure this out. Was the strut pushing against the stuffing tube, or was there a gap between the stuffing tube and the back of the strut, with only exposed teflon liner?

Sorry that happened bro. Im trying to figure out exactly whats going on with yours so I dont hav eto worry about it when I put my mono in the water. On mine the strut hits the back of the transom, so I think Im ok (other than the fact the stuffing tube is held in with a DAB of glue in one spot).

[Make-a-Wake]

Thanks guys. Mart, does yours have a brass stuffing tube??

You see, mine is an exposed double walled teflon liner........thats it..............then the 1/4 flex inside. The teflon tube slides inside the front of the strut, when the strut mount let go, the strut pushed forward and up..........there is no strength to a teflon tube or flex being bent with so much force and it gave way.

I need to add a second bolt to the strut i guess.................

[keithbradley]

Thanks guys. Mart, does yours have a brass stuffing tube??

You see, mine is an exposed double walled teflon liner........thats it..............then the 1/4 flex inside. The teflon tube slides inside the front of the strut, when the strut mount let go, the strut pushed forward and up..........there is no strength to a teflon tube or flex being bent with so much force and it gave way.

I need to add a second bolt to the strut i guess.................

I have that double insulated crap too, and it goes inside the strut a little, but both liners are also inside a stuffing tube. Looks like aluminum. Sucks that it broke on you but it brought a couple things to my attention so thanks for sharing w/us

Oh...and mine has bearings in the strut and a spacer behind the drive dog, so you wouldn't run a gap.

[Make-a-Wake]

So you see now that mine is really kinda lame............nothing but exposed teflon............so Keith, what would you recommend? A bent brass stuffing tube all the way down to the strut? Thats my plan right now unless i hear something more logical.

Mine has the bearing on the end as well..........one inside too...............but i still left a small gap which im sure was eliminated under the torque load.

[keithbradley]

So you see now that mine is really kinda lame............nothing but exposed teflon............so Keith, what would you recommend? A bent brass stuffing tube all the way down to the strut? Thats my plan right now unless i hear something more logical.

Mine has the bearing on the end as well..........one inside too...............but i still left a small gap which im sure was eliminated under the torque load.

I think if youre getting a new flex, you are going to need a new strut anyway, unless you can find a bushing for it that will work somehow...its pretty large diameter though. I dont know any way other than running a new stuffing tube.

[Make-a-Wake]

I am ordering the big speedmaster strut and a 1/4" flex turned down to 3/16 so that i have all the prop options and "normal" sizes to work with............

Here's the strut

[TotalPackage]

I have that double insulated crap too, and it goes inside the strut a little, but both liners are also inside a stuffing tube. Looks like aluminum. Sucks that it broke on you but it brought a couple things to my attention so thanks for sharing w/us
Oh...and mine has bearings in the strut and a spacer behind the drive dog, so you wouldn't run a gap.

the gap is for the shortened flex shaft under load you need a gap either way no matter it you have bearings in the strut or not.
Else the flexshaft constricts under load so a few mm of gap frees things up. You water pick up can be short a s long as it is on a planing surface like just of the rear tip on the sponsons o off the transom al least as deep as the strut.

[martno1fan]

Ahh now im with you,ive seen a few Chinese imported boats like that,it doesnt work you need a brass propshaft tube that goes into the strut.No teflon liner needed,just use grease or an oiler.To stop grease slinging round inside you can install a radio box rubber boot over the tube and the flex and it seals it enough to keep things clean without causing any drag .Also leave a gap behind the strut or as said the flex will shrink and bind which sounds like what happened.

[keithbradley]

the gap is for the shortened flex shaft under load you need a gap either way no matter it you have bearings in the strut or not.
Else the flexshaft constricts under load so a few mm of gap frees things up. You water pick up can be short a s long as it is on a planing surface like just of the rear tip on the sponsons o off the transom al least as deep as the strut.

Not really.
The bearing and spacer on my setup acts as a thrust bearing. If I had a gap like I would run with a normal flex, the bearing would fall out of the strut

[old guy]

The only time you can set up a strut with out a gap is if you have a square drive at the motor end and then you should have a thrust bearing on the prop shaft between the strut and prop. This set up puts all the pushing power on the strut on like the gap set up that puts it on the motor with the round motor coupler. If you have bearings in your strut and they are lose you need to lock them in place just my 2 cents

[TotalPackage]

Not really.
The bearing and spacer on my setup acts as a thrust bearing. If I had a gap like I would run with a normal flex, the bearing would fall out of the strut

Keith yes defintately do somthing with that . Scuff the race and epoxy or locktight it in but u need a gap at least 1/8-3/16.
Teflon liner basically just stops the cable from slapping back and forth inside the stuffing tube.They dont really change the structure. some of you probably havent soldered a piece of brass tube that goes just inside your stuffing tube at the end that protrudes out about a 1/4 inch then you let this go inside your strut you slide the liner in from the motor side till it butts inside agains the other side of the brass tube/shoulder you soldered in the stuffing tube. Installing liners is a pain after the stuffing tube is bent and installed. The liners also reduce the under water drag if the stuffing tube doesnt go inside the nose of the strut.

[Make-a-Wake]

Having alot of trouble getting parts for the new driveline.........................a flex I ordered from Delaware came in today.........it was a smashed empty box............... Seems there's always one piece that i cant find..........or get delivered to me.

Now im going 1/4 flex and 1/4 shaft instead of the step down 3/16......gonna limit me on prop a bit but im sick of surfing the internet for hours looking for that exact item i need.

Moved the batts further forward with a little modding of the old Gas tank mount.

Just lettin folks know i havent put her aside................i'm itchin to get her back in the water! She ran very well the other day til the strut/flex issue..............