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HK Pursuit 1 piece flex shaft?

7K views 12 replies 5 participants last post by  The Ghost 
#1 ·
Hi, I've recently purchased an HK Pursuit to get into FE boating and have found it to be a decent learning curve but well worth it. I've upgraded the motor to an XK4074 2000kv, 180A Turnigy ESC and an Octura race ready X645 prop. Running on 5s now the boat is ballistic. The problem now is that the flex shaft is giving up and generating a huge amount of heat despite regular greasing with a marine grease.

Does anyone know if a one piece flex shaft will slot straight in or does the stinger need to also be changed? I would go a 1/4 drive had I not already spent a decent amount of cash on the prop so I'll stick with 3/16 for now.

I also saw an interesting video regarding the different qualities of flexshaft and how some can be easily kinked. Are there better brands to look out for?
 
#4 ·
There are one piece flex shafts for it Steve Vicaro mentions them in the thread a gave a link to. Offshore electrics!
 
#10 ·
Looking at the last photo, you did not have enough clearence between the dog drive and the stinger, therefor binding as the prop loads, one piece shafts are easier to maintain as all you have to do is undo the collet and withdraw the shaft, no loss of stinger settings.

Cheers
 
#6 ·
There should not be any binding issues with ur flex. It will have to line up with coupling.

Best way to check is to slide the flex in from the transom and see that it goes directly into the base of the coupling.

You will need to change ur stinger drive but they are pretty cheap. Make sure you leave 4-5mm between the end of the stinger and the drive drog to allow for flex shrinkage under load.

Just need to really make sure that there is no binding on the flex.
 
#7 ·
Good point about the dog drive. So with the 2 piece drives removing the issue of shrinkage under load, why do they seem to be less used that the one piece flex? Is it purely a maintenance issue? I tend to only use my boat in salt water so dismantling is a constant job.
 
#9 ·
They are not as reliable as a one piece flex. Doesn't matter where you run you have to dismantle constantly to maintain them. Do you have the ability to move the motor on the mount a bit to get alignment perfect. To build a boat I would mount the motor then install the tube to match it. Also when you measure your shaft put your dog on and prop with nut. Make sure you can cover a deep prop as well with the amout of thread you have. Put a teflon washer in between the dog and the strut just in case. When I get back later today i will take a pic of one of my boats for you.

Cheers
 
#8 ·
Your in good hands! Grazacind is on the ball. Go Andy!
 
#12 ·
From all the replies looks like a stinger and flex shaft upgrade is needed. Good to know about keeping the gap between dog drive and stinger.

@ BundyRacer, aside from adding too much weight from my poor first fibreglassing attempts and making the boat list to one side when sitting in the water it's actually saved me a lot of swimming especially when I'm using it in the ocean on decent size surf. As soon as the boat is moving there's no water in the chamber. Puts a big smile on your face when it flips back by itself.
 
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