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Re: GT27 Build (Wes K)
Posted: Mon Jun 06, 2022 2:07 pm
by TomW1
Hi Wes the 29" mounting span is the minimum span for twin motors. So you are good with the 25HP motors or 20's.
I however am with fallguy keep with a single motor, less maintenance, cheaper upkeep and less cost installing,since you don't need two of everything. As for batteries there I disagree a little. Modern batteries are extremely reliable if properly taken care of. A starting and a house with with an A/B/Both/Off switch and an ACR which will open and close as a battery needs charging as I understand it. I have Interstate Marine batteries last 6 years and I changed them for not wanting the precaution. The key is to keep them trickle charged if not using them for a sustained period of time. I took mine out and put a tricle charger on them in the winter.
One last thing the Suzuki and Yamaha have nearly the same gear ratio(2.08-2.09) and will drive the same propellor size and you will have the same speed. Also are close in weight 286-282 for the twins. The weight of Suzuki twin 20's is 212. These weights are from the manufacturers listed weight and do not include oil or other fluids. Weights may be off 8-12lbs based on shaft length chosen.
Regards, Tom
Re: GT27 Build (Wes K)
Posted: Mon Jun 06, 2022 3:33 pm
by rick berrey
Tom , you and Fallguy are right in your view of Twins -v- Single as far as cost and maintenance wise , and most builds a kicker would be justified before twins . But if you put a premium on maneuverability and a spare motor , this may be one build that the cost factor may be worth it with ( Wes K ) ,s intended use
Re: GT27 Build (Wes K)
Posted: Mon Jun 06, 2022 4:25 pm
by Dougster
I'm sure two cost more than one. Significantly better manuverability cost more than white knuckles at the dock too. On the GT27 I'd like two if I could manage it. I'd run 'em off independent fuel tanks too.
Dougster
Re: GT27 Build (Wes K)
Posted: Tue Jun 07, 2022 12:50 am
by fallguy1000
Well, two Suzu 20s are going to deliver about 6 amps apiece from their rated 10 to the house. Or 12amps an hour. If you have 200AH house batteries and discharge them to 100AH, it will take 8 hours to run them back up. This is the issue and why commercial week long houseboats go bigger.
The alternators on the Skoota are rated for 32A eacj. Figure delivery of 25 each. if I run batteries down 100A, gonna take me 2 hours to charge them. I do have
Solar panels, but maybe get 15-20 amps an hour.
Charging does matter. Just keep it in mind.
Re: GT27 Build (Wes K)
Posted: Tue Jun 07, 2022 6:26 am
by OrangeQuest
One thing about the small Suzuki outboards is they don't need a battery to start, they still have a pull start built in all the way up to 30HP. So, you really don't need a separate starting battery for them and only need to have house batteries. This is one of the things I considered when buying my little outboard, no need for a battery to start so I can use just one battery. While the outboard is running, it only has to maintain that one battery too.
One of the things that does bother me is the different chemistries you can get batteries now and they all require different methods of idea charging patterns for best performance from them and long life. Then add a starter battery is made different than a house battery but they could be charged together at the same time. This is why the added expense of an ARC to charge them separately. BTW, when I was researching how much the starter draws for a little 25HP Suzuki, the same starter part number goes all the way up to a 90HP Suzuki. So I don't think the starter current draw would be much of a difference between a 25hp and a 50hp. That could influence battery selection. Do you need a starter battery that is built for high current draws or can you get away with spending money on more deep cycle batteries? Maintaining batteries of all the same chemistry is cheaper and easier than charging different types.
Twin Suzuki 25HP product 14 amps each but one 40HP or 50HP AV only produces 19 amps. Neither scenario would NOT be for recharging low batteries or maintaining high amperage draws from the house. For those high current draws, maybe a portable generator would be the way to go.
Re: GT27 Build (Wes K)
Posted: Tue Jun 07, 2022 7:08 am
by bklake
Wes, I just got a Suzuki 9.9. Remote, 20", power tilt. The 9.9-20hp are all the same engine with a computer change to get hp. I have not mounted it to my boat yet but I have been working on rigging it in my spare time. Suzuki is about the last one that will sell you a remote directly. All the others small remotes have to be sold and installed by a dealer. I'm guessing you want a remote motor?
120 lbs seems about right until you add the weight of the controls and wiring. Add at least 10-15lbs there. I'm a big fan of Suzuki.
Re: GT27 Build (Wes K)
Posted: Tue Jun 07, 2022 9:31 am
by fallguy1000
OrangeQuest wrote: ↑Tue Jun 07, 2022 6:26 am
One thing about the small Suzuki outboards is they don't need a battery to start, they still have a pull start built in all the way up to 30HP. So, you really don't need a separate starting battery for them and only need to have house batteries. This is one of the things I considered when buying my little outboard, no need for a battery to start so I can use just one battery. While the outboard is running, it only has to maintain that one battery too.
One of the things that does bother me is the different chemistries you can get batteries now and they all require different methods of idea charging patterns for best performance from them and long life. Then add a starter battery is made different than a house battery but they could be charged together at the same time. This is why the added expense of an ARC to charge them separately. BTW, when I was researching how much the starter draws for a little 25HP Suzuki, the same starter part number goes all the way up to a 90HP Suzuki. So I don't think the starter current draw would be much of a difference between a 25hp and a 50hp. That could influence battery selection. Do you need a starter battery that is built for high current draws or can you get away with spending money on more deep cycle batteries? Maintaining batteries of all the same chemistry is cheaper and easier than charging different types.
Twin Suzuki 25HP product 14 amps each but one 40HP or 50HP AV only produces 19 amps. Neither scenario would NOT be for recharging low batteries or maintaining high amperage draws from the house. For those high current draws, maybe a portable generator would be the way to go.
Twin 25s would deliver better output. Say they yield 10 each, that would be 20 and easily beat the 50 that yields 15. My point is he needs to pay attention or he'll be running engines forever to charge the house. Even in the twin scenario, he has to run two engines to beat the 50..
Re: GT27 Build (Wes K)
Posted: Tue Jun 07, 2022 10:52 am
by rick berrey
A small generator will run 6 to 8 hours on a tank of gas , most likely cheaper than running an outboard motor to charge batteries if your not moving . I would thin between some solar , a generator and outboard , there would be no problem with power supply .
Re: GT27 Build (Wes K)
Posted: Tue Jun 07, 2022 11:18 am
by fallguy1000
rick berrey wrote: ↑Tue Jun 07, 2022 10:52 am
A small generator will run 6 to 8 hours on a tank of gas , most likely cheaper than running an outboard motor to charge batteries if your not moving . I would thin between some solar , a generator and outboard , there would be no problem with power supply .
Yeah. 400-800 watts of solar would be a big help, too. I bought residential panels for my boat because shipping panels was $200 each. Paid $275 for 620 watts and about $250 for cables and controllers.
Re: GT27 Build (Wes K)
Posted: Tue Jun 07, 2022 2:15 pm
by TomW1
If Wes wants to go twins the alternator outputs of the Suzuki is 14amps and for the Yamaha 16amps, run one to the starter and one to house. I would not even think about twin 20's. Remember as we are downsizing the motor size we are down sizing the prop size and the control that the prop has on the boat. Like Dougster says I would use two fuel tanks so that if one gets contaminated the other will still run that motor. As far as the Suzuki 25 it can be either pull or electric start which OrangeQuest did not mention. As far as batteries go there are different technologies out there. The most commonly used in boats are AGM both starting and deep cycle they can go up to four banks. I hve had great succes with Interstate as I can get them locally but Bass and Cabella's sell quality batteries. You can also get an on boat water proof battery charger, most are automatic and fully charge the battery and then drop to a trickle charge to maintain the charge. When you get to a dock with power just run an extension cord to it.
Well I am getting long winded again,
Tom