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Author Topic: 1 Seaport Tug, Motor Number 4!!!  (Read 2463 times)


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1 Seaport Tug, Motor Number 4!!!
« on: November 14, 2012, 09:26:42 am »

Hi, i am ( still ) converting my Seaport tug after reading all the forums and how easy it is. But i am new to model boating and have a few problems at the moment. I will post pictures when i learn how to do it! Ripped it all apart, fitted a Zebra 3 channel system ( the third channel operates the fire pump ) new prop shaft and prop, 6v 5ah SLA battery, Mtroniks Plug And Play 15a speed controller etc.  The 1st motor ( original ) was fitted with a 45mm 4 blade brass prop and yes it burned it out ( over propped? )  Second motor was a generic 380 type from Howes models  ( and the prop was replaced with a 3 blade 30mm one ),  slow on the water until i realised that the motor was rated up to 18v so i guess the motor could,nt get up to speed?  3rd motor ( still 30mm prop ) was a Graupner Speed 400 6v version which ran great, a good speed ( i know it's not a planing type hull ) but suddenly stopped in the middle of the lake. When i got i back i found that the motor had burned out ( my son had left his hand on full throttle ) The motor had either overheated because one of the engine mounting screws had come out of the mount and promplty jammed against the coupling or it over heated because it was running hot , not sure which happend first. On the forum lots of people state ' oh, i just used the original prop / shaft / and motor and it all runs fine'  But what i don't understand is how the original motor can turn the original ( 40mm ) prop any way, is it not too big to start with compared to the size of the original motor? I have an been looking at various motors and i have got it down to two types, another Speed 400 ( and hope the original one just burned out due to the loose screw ) or the Mabuchi 545 both of which can be found on the Cornwall model boat site.  So, as i don't mind ripping  out prop shafts and engine mounts to get this right i am open to suggestions to what motor you guys would recommend. The prop shaft ( 4mm )  by the way is free running ( though filled with model boat grease ) with a little play for / aft so it is not running tight. Any suggestions / opinions MOST welcome, regards, Dave.


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Re: 1 Seaport Tug, Motor Number 4!!!
« Reply #1 on: November 14, 2012, 11:37:21 pm »

Hi, mine runs on a low amp 540 size motor ( something like a Speed 500E ) you'll need to change the mount though, prop is a three blade that just fits inside the kort ( don't remember the size ), the motor gets barely warm .

If it's any help here's the build -

I've never been so sure of something I wasn't sure of...


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Re: 1 Seaport Tug, Motor Number 4!!!
« Reply #2 on: November 15, 2012, 08:00:58 am »

Interestin thread, i've also got the seaport with the original motor, 15 amp viper esc and a 6 volt lead acid battery with a planet t5 radio, on a dry run ( literaly ) it works fine so it'll be interesting to see what happens when it does eventually reach the water
regards Jack.
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