bigal222500

Hi all. I am new to RC boats. have had lots of RC trucks over the years. All being electric. I bought a used RC Black Jack 26 Red /black boat. I went to use it and seems like it is not tuned right. I am using 20% nittro fuel. It has the stock engine that it came with. Just not sure why the idle seems so high. I tested it in my large pool and as soon as I put it in the water the boat takes off at a high speed. So I backed the idle screw off and the boat dies when I am not on the throttle. Is the boat supposed to have a nice smooth "slow idle" or is it normal for it to have a high idle? Also the fuel screw...any idea where that should be positioned? I screwed it all the way in and then backed it off at about a quarter turn each time. I noticed it sounds the best and gives good response around the two complete turns off the all the way tight position. Then the throttle is at the position where I can see maybe a quarter of the open postion. Is that about right? Any help would be great. thanx

Alex

Ron Olson

My Feedback: (1)

Nitro cars and trucks are slightly different animals than boats, I know as I ran them before coming back to boats.
You're going to have ot run the engine a little fat as the prop will lean out the engine once it hits the water. Start off to where it has a slight lag when you blip the throttle. If it revs quickly, it's too lean.
If you're using car and truck fuel, save that for them. get some boat fuel which will have a higher oil content. Get some around 40% or more if you want the boat to scoot.
Don't mess with the idle speed screw as all we need it for is to keep the barrel from coming out. Use the trim on your TX to adjust the speed.
Set the idle on you TX so that you have enough space to put the tip of a toothpick in there, roughly 1/32".

bigal222500

Great info..thanx

Boat fuel huh...I need to go looking for that. My local hobby shop sold me this Nitro fuel that has 20% on it and thats it. I'll go looking for boat fuel tomorrow. I will use the trim on the radio and give it a go tomorrow. The box which the boat came in says to use "blue thunder 20%" but your saying that 40% is ok??

Ron Olson

My Feedback: (1)

Sure, 40% (or more, up to 65%) is fine and it will run better,
Truthfully, I've never been a fan of Blue Thunder even back when I raced trucks. Horizon Hobby/Pro Boat is only pushing that because it's what they sell.

I loved going back ot the local racetracks and asking the nitro truckers if they'd like to try some 65% but at first they're shocked and worried about them sneezing an engine. I have a little OS .12 CV-R that I run 65% in all the time in a small mono hull. It's the oil content and a richer carb setting that helps to make the engines last. I don't recommend that you go as crazy with the nitro like I do but something in the 40% range will do you nicely. The higher nitro also makes it harder to adjust the carb as it's more weather sensitive.

bigal222500

So what is a normal idle speed for this boat? Should it barely move in the water while idling then? Or is it normal for these boats to have a somewhat high idle?

Ron Olson

My Feedback: (1)

If it's too high then you'll have to worry about overheating the engine and/or blowing it up. Find a happy place where it will stay running but not where you think that it's too high.

gralls4771

Just a word of warning about the blackjack, If you have seen the aeromarine hardware setup for the blackjack it looks really good but they say to remove the turnfins. They say that turn fins dont belong on a Cat........well they belong on this Cat. Im not sure they even tested the BJ in this setup. I tried this idea of removing the turn fins today and the boat was nearly out of control, high and low speed. It actually rolled once, thankfully ending upright. Aeromarine has great products but removal of the turn fins on this boat is a terrible idea. I had the speed pulled back to 25mph on the GPS and it was all but out of control. LEAVE THE TURN FINS ON.

jdoug

I'm with Aeromarine...turn fins don't belong on a cat. They are a band-aid to a problem with this hull.

gralls4771

Maybe turn fins dont belong on a cat but for the blackjack, the hull is the way it is. Thats fine if they are a bandaid, Im just saying the boat is nearly out of control with out them.

pissedoffpete

I took off my turn fins and boat was all over the water. Fishtailing and slipping and sliding in turns. I almost rolled it. Whatever speed can be gained is not worth the loss of control in my opinion, Leave fins on. The motor is a pain to tune. I am waiting on a GOENGINE.18 Will post comments once I get it in. It may wait til I blow up stock motor or get tired of it. Overall I like the boat even more than my Thundercat 31 but probably for the looks and the fact it was my first rc boat. Thundercat blows it away though, not even close in stock forms. BJ 26 uses much less fuel which is a plus.

bigal222500

going to try and tune it again this weekend.

gralls4771

I have a Go 18 in my blackjack, if you get one you will love it. Very fast engine.

pcg33k

I to have a Go Engine in my Blackjack and that thing hauls ass this is the motor that should have come with it from ProBoat. You'll want to buy spare parts or upgrade because the stock parts seem to break right away. I'm waiting on a new rudder system, broke the flexshafts u-joint while breaking in the new Go Engine.

ERV JR

How fast is it ? gps #S ?

pissedoffpete

I am happy to hear others opinions on go engine. Since a twiste liquid outdrive is out of question, how is The Aeromarine setup? I dont like the fact it does not have a nut to hold propeller. Como Chingas! whats up with that? Anyone ever lose a prop? I want to replace stock out drive with rudder setup but can live with it. The other day I ran my BJ26 and had it running dead even with my thundercat 31 I could hardly believe it! I had my friend driving the BJ 26 side by side. True to form, the TC 31 got faster and my BJ got slower. Much slower. I finally noticed silicone hose seperated on exhaust. Another repair, true to form. Its a good thing the boat looks good because its a FIAT. Fix It Again Tony

WILDGAS

Where do you find the GO Engine?

Ron Olson

My Feedback: (1)

www.funrcboats.com is now selling them, a reliable company to deal with.

gralls4771

If your looking for hardware for the blackjack, I saw a really nice hardware setup on a BJ brushless from fullers fast electrics. Aeromarine looks good too but that no prop nut thing made me shy away from it too. I understand the directional force of a moving prop but props are too expensive to be held in place by a cheap peice of silicone tube.

pissedoffpete

I saw on another thread someone using flex drive, strut and rudder from proboat hydro. Interesting idea. I will be checking prices on setup. I suppose it will be a while before new red anondized hardware for BJ 26 is available from proboat. Pictures are up on their site

pissedoffpete

I saw on another thread someone using flex drive, strut and rudder from proboat hydro. Interesting idea. I will be checking prices on setup. I suppose it will be a while before new red anondized hardware for BJ 26 is available from proboat. Pictures are up on their site

misshydro

The vegas flex cable are the same size as the proboat.both are .150. You can get the flex coupler to fit the go.21. I bet it will be 1/4 by 28. that the most common thread size .21-.32 uses. The other thread that would be me. I had that idea to use the vegas parts.the thread would be ratBJ26 mopartybobs blackjack that I'm working on for him.

bigal222500

OK its been awhile since I touched this thing. I have been working like crazy since my last post. Took it to the lake today and seems like the tune is close. However, I think I have another problem. When I open to full throttle it seems like it is not catching. Sort of like a transmission on a car when a tranny is slipping and not catching in gear. I hear the engine on the boat at high RPM but the boat is not moving very fast. Then it seems like it then catches and kicks in and goes fast and then it slows down again. This is all while maintaining the same throttle. Any idea what it could be?

Ron Olson

My Feedback: (1)

It might be that the strut is a little high as once it's getting up to speed and higher on plane the hull is lifting the prop higher out of the water.

bigal222500

So can I do an adjustment to correct this?

TCHedOff

Your prop is cavitating. If you have an adjustable strut, lower it as mentioned and try adding a little negative thrust. Also try changing the cup on your prop - a little less may help. If these dont work, time to think about getting a different prop.... my $.02.