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Engine Overheat Issue - Prather Commander II

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Old 10-13-2017, 05:21 AM
  #1
westwind77
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Default Engine Overheat Issue - Prather Commander II

A hobby store went out of business and they found a 'new in box' Prather Commander II RTR and basically gave it away, could not say no, I owned one years ago.

The engine (Zenoah 26PUM) is cutting out and dying after a few minutes of higher speed running and there is a lot of steam/smoke from the bilge when it dies. It did this right out of the box so I installed a new water pump with no improvement. I also swapped the carb with no improvement either. I highly doubt it is a lean/rich issue as once it starts to get 'hot' you can tell when it is getting close to dying.

I would like to improve the water flow/pressure to the engine, what is the best way to have this done? The current pick-up is in the middle of the trim tab (see photo)

You can tell it does not protrude very far down and I am concerned it does not get the flow it needs. I honestly do not remember how my original one was 20 years ago. Then again that was an 11cc nitro vs this one being a Zenoah 26 PUM.

(I updated the servos/controller/battery pack/etc as well)

I am open to any advise/suggestion you might have.

On a side note I purchased a ProBoat React 9 for my 6-year old son - that thing is great! He loves to run it, so do I. I can handle anything you throw at it as well.
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Old 10-13-2017, 06:53 AM
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Tidnab
 
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Those trim tabs with the water pickup built in them aren't very good.My first boat had them and very little water was coming out the side of the boat. Get a rudder system with pickups in the rudder, as they force more water into it. I also bore out my water fitting to 1/8" or get larger id fittings and use 5/32" water line from Zippkits XL Silicone Water Line 4 Feet Model Boat - $4.00
Get all water line fittings to match the large water line. Zippkits has rudders and about anything you'll need.
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Old 10-13-2017, 10:21 AM
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westwind77
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That is great info. From what I can see though I have to change out all the rudder hardware for this to happen. Do you think it is possible to just replace the rudder, and/or rudder and bracket and leave the mount on the transom. I would rather not have to fill and re-drill holes to mount a new one if possible. (see attached)
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Old 10-13-2017, 12:51 PM
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To make this work without much alteration i would remove the water pick up in trim tab and fit another piece of this brass tube which would have a near 90 degree bend in the bottom so water can run into this tube freely with no restrictions, also i would remove the water pump and plug the pulse nipple in engine as those pumps work on a diaphram and the internals do perish after time which could be your issue right now. make sure you can blow through the end on water cooling tube and feel air coming out freely on the opposite exit end. this is you problem [ over heating ] due to lack of cold water intake.
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Old 10-13-2017, 03:36 PM
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My thought is, to do it right, scrap everything on the transom and start fresh. I'd look here and see what's available:
https://www.rocketcityracing.net/?pr...ype=product&s=
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