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LiPo Capacity for Receiver/Servos

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Old 09-24-2017, 06:52 PM
  #1
429CV23
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Default LiPo Capacity for Receiver/Servos

Is 1300mah sufficient to run the receiver/servos on a gas boat? I'm wondering if I should have gone with larger capacity, maybe 2200+? Trying to balance run time and size/weight.
I'm really tired of shredding my fingers trying to start this G26PUM. I fire it up at home the night before going to the lake, usually 4-5 pulls and she fires. Get out to a cove, get everything out to run it, and 100+ pulls later I'm ready to put a brick in it and sink it. So I bought an Arrow Shark E-Starter. Damned expensive, about what I paid for the boat new in box when adding in the battery and charger/balancer. But, I see it as a 1-time purchase that can be transferred to any boat I upgrade to in the future, and I'm not planning on racing, so the added weight isn't a huge issue.
Thanks!
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Old 09-24-2017, 10:20 PM
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are you running a 2s lipo ? if so the output voltage of this lipo pack is over 7 volts and can damage your servos if there not suited to higher voltage. you should run a voltage step down unit for safety or go for a LiFe 2s pack as these are lower in max voltage. 1300 mah is ok but i would keep an eye on the voltage remaining after a couple of runs, yes 2200 plus would be better. Hobby King have some good Zippy receiver LiFe Packs around the 2400 mah size quite cheap.
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Old 09-25-2017, 12:22 PM
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How many servos are you running and what is your average runtime per day? I would guess you are only running 2 servos (throttle and rudder, maybe a third if you have a reverse gear to engage, certainly not more than 5 if you go whole hog and add a plug heater and mixture control.) If you are not running any super fast super hi torque digital servos that can actually pull amps but just standard size analogue servos for 2 servos a 500-750 mah, 5 cell NIMH battery. More servos or more than an hour or so runtime more mah but probably not more that 1500mah. By the way, just about any servo that is rated for 6V and most receivers can be run on a LiFe battery (but not a LiPo, too much voltage, those require either a BEC to step down the voltage or a rating of 8.4 volts) LiFes are safer and less fussy than LiPo batteries and don't commit suicide if you leave then charged. They are a little fussier than NiMHs but not bad. D.H.
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Old 09-25-2017, 02:00 PM
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Based on your subject and question(s?) you need some personal one-on-one help. Seriously, either find a club or a good hobby store with knowledgeable people.
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Old 09-25-2017, 05:29 PM
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Quote:
Originally Posted by rgburrill View Post
Based on your subject and question(s?) you need some personal one-on-one help. Seriously, either find a club or a good hobby store with knowledgeable people.

Why is that? Is the operational current draw from servos included with a RTR boat intrinsic knowledge?

And ... there are no clubs close to me, and neither of the local Hobbytown stores have associates that have any knowledge about gas boats. Why do you think Al Gore invented the internet? Sharing of information!

Last edited by 429CV23; 09-25-2017 at 05:39 PM.
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Old 09-25-2017, 05:40 PM
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Thanks for the info guys! The R-One unit included with the starter provides ~6v to the receiver from the LiPo pack, eliminating the need for an additional battery. I downloaded the user manual, and they recommend a 7.4v LiPo for stock engines, although the voltages listed on their site are 11.1 and 14.8v. The seller included a new 7.4v, 6000mah pack with the boat, looks like I'll be able to use that.
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Old 09-25-2017, 10:09 PM
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yes thats a good size 2s lipo, should supply plenty of current to the rx / servos etc.
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Old 09-26-2017, 05:42 AM
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How is the arrow shark electric starter these days. I put one on a customers boat a few years back and thought it was nice, but the material they used was terrible. It would not hold threads in the metal they used. I was thinking that it would be great if they just used better grade metal. If it is still bad and does not last for you also look into a ez-start for you 26. still a pull starter but they give more turns per pull and start engines better. But really once you get you carb set right, it should be 2-3 short soft pulls with finger in carb to prime, and 1-2 good half pulls to start. If she is not starting easy for you something is just not right. Probably something small. Alway keep in mind when you have a stock Zenoha, they are a water cooled weed eater motor. That basically are the same motors sold on red devil weed eaters, weed eaters are sold to woman who use them on there needed yard work...LOL. do not always go to guys playing with model boats. if the average woman can not start her weed eater, they would go out of business. So really it's not the gas motor. That was nitro days.LOL, Gas boats are fun, if you ever want to sink your gas boat. slap yourself first because it's you....LOL just playing. have fun and let us know how that newer arrow shark starter works out.
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Old 09-27-2017, 05:38 AM
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Quote:
Originally Posted by expresscraft View Post
How is the arrow shark electric starter these days. I put one on a customers boat a few years back and thought it was nice, but the material they used was terrible. It would not hold threads in the metal they used. I was thinking that it would be great if they just used better grade metal. If it is still bad and does not last for you also look into a ez-start for you 26. still a pull starter but they give more turns per pull and start engines better. But really once you get you carb set right, it should be 2-3 short soft pulls with finger in carb to prime, and 1-2 good half pulls to start. If she is not starting easy for you something is just not right. Probably something small. Alway keep in mind when you have a stock Zenoha, they are a water cooled weed eater motor. That basically are the same motors sold on red devil weed eaters, weed eaters are sold to woman who use them on there needed yard work...LOL. do not always go to guys playing with model boats. if the average woman can not start her weed eater, they would go out of business. So really it's not the gas motor. That was nitro days.LOL, Gas boats are fun, if you ever want to sink your gas boat. slap yourself first because it's you....LOL just playing. have fun and let us know how that newer arrow shark starter works out.
I'll post info about the starter, and install pics if there is a good 3rd party host; looks like photobucket no longer has working links. I haven't found much info or reviews about the starter. They have 2 versions listed on their site, one looks like an updated version of their original design with the open drive, I bought the TS-760 Marine, which is all sealed. The other version has a servo actuated control, the TS-760 has the electronic control.

I had a terrible time getting the engine started the first time. Seems like it isn't getting fuel like it should initially. I think I'll disassemble and clean the carb; it is brand new, but has been in the box for some time, maybe several years. I'll probably install the water pump while I have the engine out, that way I can run it at home to tune it.

On a side note: do you produce any gas hulls with a D-pad? I'd love to build a 48-50" jet; would be cool taking it out when I take the 23' jet to the lake, especially if a mini Place Diverter were available.
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Old 09-27-2017, 05:20 PM
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If the engine doesn't start in a few pulls a electric starter is not the answer. Fix the problem why it won't start right up . Most people just don't understand how to start a two stroke. First you choke the crap out of it one or maybe even two pulls until you have induced a slightly flooded condition then you hold the throttle wide open and pull until it fires up.

An electric starter in a boat is not going to be work worth a darn once it is full of water a few times. All sealed means nothing to water it will get in. All sealed means water gets in but will never get out. Carting around a big ole' pack that can't get wet not good either. If the engine isn't starting it is just going to burn up the starter system.
It is just really just a gimmick.
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Old 09-28-2017, 05:14 AM
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Quote:
Originally Posted by danielplace View Post
If the engine doesn't start in a few pulls a electric starter is not the answer. Fix the problem why it won't start right up . Most people just don't understand how to start a two stroke. First you choke the crap out of it one or maybe even two pulls until you have induced a slightly flooded condition then you hold the throttle wide open and pull until it fires up.

An electric starter in a boat is not going to be work worth a darn once it is full of water a few times. All sealed means nothing to water it will get in. All sealed means water gets in but will never get out. Carting around a big ole' pack that can't get wet not good either. If the engine isn't starting it is just going to burn up the starter system.
It is just really just a gimmick.
If there is enough water in the hull to fill the starter gearbox, it'll be at the bottom of the lake. It may be a gimmick ... until it dies in the middle of the lake and I don't have to throw on a life jacket and swim out to retrieve it or fire up the boat to go get it. Even if it is a complete gimmick; I'm OK with that. I see it as a convenience feature. If electric starters in general were just a gimmick, you'd be manually cranking your car to start it.
I've never run electric boats so I am not too familiar with electric running gear. Do they wrap their packs to keep them waterproof? If so, I'll look it up and follow the same practice if it is a safety issue.
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Old 11-03-2017, 03:56 AM
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My point was if it takes 100 pulls to start it what will a electric starter do to help that. Fix the engine so it starts first/second pull.
The boat gets filled with water every time you have a wipeout. If your boat sinks because water has filled the hull it will be at the bottom first time out.
The boats don't need to start again once they are in the water. If it dies in a wipeout and water has filled the hull a single revolution of the starter after water has gotten in the engine will wreck the engine and most likely burn up the starter/battery or switch . If it is just dying while running the engine needs to be tuned or fixed so it isn't stalling.
Electric boats are completely sealed and you can't completely seal a hull that has a engine in it.
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