JAE 12G Build

[Eric Drust]

Finally after 2 years I managed to finish this boat. I just need to get it dialed in now. Thanks to everyone who helped me acquire the parts for this project, I appreciate it. My goal was a reliable boat to have some fun with. I won't be racing anyone, but I still hope to get it going pretty fast.

I had a heck of a fun time figuring up what to do about charging the receiver battery pack. I ended up connecting wires to my throttle pushrod and the stuffing tube. To charge the batteries I turn off the receiver switch, connect alligator leads to my strut (negative), and the throttle pushrod (positive), and then hook up my charger. Now I don't have much reason to remove the radio box tape.

 

[bjacobsen71]

Nice looking rig there, just about to start building mine, good to see some close pics of the engine compartment, I'm going to be using an OS .18TZ in mine and now I have some ideas how to hook up the carb (as my engine has the slide carb). A bit off the subject here but anyone here using this engine, and what prop should I start with (I'm looking at just sport running as well, but I'm at 5000'), and while you mentioned it pulsetech, what would a good starting pipe length be on an .18? By the way Eric, what engine are you running?

Brett

 

[Jim Mamaril]

Looks good Eric,nice strut too I would shorten up your pipe to about 7 1/2 - 7 1/4 from center of cyl. to the weld on your pipe, also you might want to move your turn fin to the 2 center holes.

Eric, A 1440 is a good prop to start with.

 

[Eric Drust]

After running the boat the first time I did notice some fog forming on the inside of the radio box lid. It went away about an hour after the boat was no longer in the water. Leaving the tape off long term does make sense though.

As for length on the pipe, is that from the center of the cylinder to the fattest part on the pipe (is that what you mean by weld)? What will a shorter pipe gain me, more RPM, or more torque?

My engine is a .18 Go Engine. From all the research I have done on these, people either love them or hate them, there is little in between. I am impressed with its power from when it was in my previous boat. However, I am not impressed with the lack of available parts for these engines. They are for the most part "throw away" products.

Some advice for others out there. Don't paint your boat dark blue. This paint was something I had on hand so I went with it. Well, it is very hard to see the boat out on the lake, other than the rooster tail behind it.

 

[Eric Drust]

I contacted lights about the Go engines, but he only handles the racing versions, not the sport engines. If I get this boat working well, I plan to build A JAE21, and will run a racing Go engine in it, with belt starting as well.

I am assuming the pipe length is the center line measurement. Either way, I will go for 7 3/4, and then cut a wee bit more off at a time to get it ideal.

 

[Jeremy Linney]

Nice looking rig there, just about to start building mine, good to see some close pics of the engine compartment, I'm going to be using an OS .18TZ in mine and now I have some ideas how to hook up the carb (as my engine has the slide carb). A bit off the subject here but anyone here using this engine, and what prop should I start with (I'm looking at just sport running as well, but I'm at 5000'), and while you mentioned it pulsetech, what would a good starting pipe length be on an .18? By the way Eric, what engine are you running?
Brett

Hey Brett, I have a few OS 11M rotary carbs new in package I will sell. These were used on the OS 12TZ but would probably work fine on the .18 as well. Measure the throat on your carb and PM me dimensions if interested.

 

[Eric Drust]

I measured my pipe and header, and if I cut off all the header I can to get to the most curved portion of it, I would still have about 9 in to the fat part of the pipe from the glow plug. What options do I have now, find a shorter pipe?

 

[gil sonsino]

It's also nice to see that boat lovers never give up of their projects...two years would be too much for me.I see in your pics that your receiver is unprotected...hope you do not run this way......use simple rubber baloons aound it and to your battery pack too. What Greg said is very important...after each session It is highly recommended to open the radio compartment to disconnect the battery plug and search for water or even simple moisture...a radio tape costs less than any radio system........I would use a Mac 2,5cc pipe to solve the lenght problem to be in the 7 1'2 " enough for your .18 engine.

Have a very nice boating

Gill

 

[Eric Drust]

I am not too concerned about the receiver. I disassembled it and coated the PCB in a light layer of epoxy. The pins on the battery and servo connections might be an issue, but they have a light layer of dielectric grease on them, which should help prevent corrosion. This receiver came out of my other boat and was used this way with no damage too it.

Additionally, if things go well I will run two or even possibly three tanks of fuel through this boat a year. I don't think that is enough use to get too concerned with water damage. I only ran one tank of fuel through my other boat last year, and two tanks the year prior to that. Gathering up all the equipment needed to run a nitro boat, making sure everything works right, getting it physically to a lake, then coordinating with someone who has a real boat to use when my R/C dies out in the middle of the lake, and finally having the weather be suitable, just never seems to align for me.

This whole project was about building the boat. I know this is probably complete blasphemy, but I just don't get a lot of excitement from running anything R/C. Once I build something I like to run it and get it working well, then I never use it anymore. Once I get this JAE12G running right (with a new pipe for example), and everything seems pretty reliable, I plan to move on to a JAE21G. I just bought a mini sprint, but I got it pre-built and already regret it. The mini sprint looks like it would have been another fun building project as well.

 

[Neil LaGarry]

Ive been running one for 2 years. Loads of fun. Next year we will have a class to run her in. Ive run her in the .21 class rigger and open rigger. Yes i was lapped. We finally have a few guys that plan on running one next year. You can run her alone. if needed. I finally replaced the hull after 2 hard hits into #4 buoy. Each one is different running out of the box . The first one had a nasty left curve. The second hull wants to go down the lane sideways or the back was tiring to go ahead of the front. What the heck I'll move the rear boom some and add a washer behind the rear turn-fin. screw. more testing is needed. We raced her so when I go to the test pond we can experiment .I ran 1/2 lap and shut her down. That's not the time to test. We test Thursday evening. I'll get her going the right way. My 2nd hull is more colorful and I won't loose sight of her in the sun. I hope,the sun sets right in front of the stand , sunglasses are needed. I hope to stay clear of buoy #4