kwiktsi

So, to bring this thread back up- what is the general consensus on the BJ 55? I am considering getting one to bash up at the lake when we have our boat out. I'm not looking for ballistic speeds, it is too rough for that anyway, I am just looking for a fun boat that can handle some "rougher" water and look cool doing it . I was thinking of this or the Aquacraft V24, the price of the V24 is certainly more appealing!

I have my fast electrics for when I need the speed on smooth water .

black talon

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i've been running my boat with a barr cut x472 and gps'd it at 41 mph. i just ordered a 7016 2 from voodoo to see if she can handle it and make more speed. the only problem i've had with mine is it spun out in a corner and snapped both rudders off. i replaced them but am thinking about getting a set of from aeromarine. they make rudders that are direct replacements for the bj 55.

bahamadude

Yes that must do !!
Yes get the aeromarine rudders and you wont look back .

So farI got 44 mph on my black jack. using x572 prop.

I am goin to remove the clutch and see how fast she goes.
My buddies got hi to go 50 mph consistenlty. I cpied some of his mod and am almost there.

My engine is moved 4 inches forward measuring from the plug. His was 2 inches.
He used a stock engine modified by his hand with a dremel, His boat would flip on full throttle on the straight. No joke This was with a litle head wind. My radio is also moved forward too.

theking549

hey, guys

i'm glad you brought this forum back to life, i just finish modding my blackjack i spent about $700 in parts did all the labor my self 52mph with a clutch. should get about 60mph with out the clutch mods: ported cylinder head, reeds, reed ported, light piston, window ported piston, stuffed crankshaft, aeromarine rudders, clutch, 813 carb, zero drag seals, 2'' wide band tuned pipe, cool water jacket, 6717/3 prop, 275 prop. etc

for those who wants aeromorine rudders, in my case my engine is fully build and runs hotter than a stock engine i need alot of water pick up. aeromarine rudders does not pick up much water, im using the stock pick up tubes they work great.

for those who wants to try a 6717/3 prop on a build motor i suggest dont try it you will throw your money away. my engine has too much torque and it just revs until the prop catches on.

theking549

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kwiktsi

Has anyone tried an Octura X670? I was thinking it may have more top end than a 572 due to the increased pitch and decreased diameter. Any info on this?

I found a used BJ55 that I am going to look at and hopefully buy tomorrow as long as everything is as described, so I am just trying to get ideas.
Joe

bahamadude

Yuo guys are good !!

Confirmed I was about to buy a X670 prop.

King549 which clutch do you have on that boat ?

I have a ccracing steel pipe laying around and I might stick it inside .

Next I found out that the exit shaft tube is in the wrong postion. That tube needs to be lowered some and that boat may really roll.


Nice setup !

kwiktsi

Exit shaft? Are you referring to the prop shaft and strut? If so, I noticed they sit kind of high as well. Drop it a bit and it should get the boat out of the water a bit more to make it run"looser" and gain a little speed.

bahamadude

Yes thats correct kwiktsi

King 549 I have to see a video showing GPS for confirmation for that speed of 52 mph !!

Reason being that motor which you have "souped up" should cause your boat to blow over because the motor is still in the orginal position.

With that kind of power your motor should be at least 2 inches foward. Mine is currently set at 4 inches which is the max.
adding more weight upfront would help to keep the nose down especailly with some head wind.
I plan to increase power, so that the reason for me moving it all the way forward.

Not trying to start a flame war, but just providing some information to help us achieve the max speed from our boats.

If you havent experienced any blow overs , can you tell me why ?


Your thoughts ?


Thanks

kwiktsi

Is there enough length in the stringers to move the motor 4" forward, or do you have to add to them? Yeah, looking at some of the setups here, even some modded ones- I can see there is still a bit of tweaking left to make it right- strut height and angle, prop selection, rudder angle, motor placement/CG, etc. I see a lot of people move the fuel tanks up- which works as long as it is full . As the level drops, your CG moves. Best to keep the tank right on the CG so it isn't affected by fuel levels and use your motor and other gear to set the balance as much as possible. While I try not to add "dead weight", a boat this size- especially modded, won't suffer much if you had to add some additional weight to the nose. You'd probably gain more from the boat running through the water properly than you would lose from the added weight .

I'm anxious to go pick mine up today! It is about an hour and a half away, so I'm hoping the guy was open about everything over the phone. Seemed to be, we'll see in a little while .

theking549

hey guys,


i will be posting more pictures and videos soon, i polished the rudders and they now look like a mirror. (nice) after i moved the gas tank all the way to the front and changed the rudders the boat stopped turning over, now i can make sharp turns and even drive it in choppy water or when its windy. i managed to nailed center of gravity in the a@@ cause the boat handles perfect even with a empty gas tank. just try it and see it for your self. is just like adding weights on a wing of an airplane


you can achieve any speed you want as long as you have money to invest

kwiktsi

OK, I bought the used BJ 55 today. Not a bad boat, pretty slow though lol. Overall it looks and sounds mean as hell on the water! I did notice that the bearing on the clutch is going, no biggie, I can get a new one for ~$6.

Spent time taking things apart, cleaning, lubing, checking bolts, etc. today after I got a quick run in to see how it was as-is. I noticed the boat rides pretty "wet", so after I ran it, I dropped the strut as far as it would go and adjusted the angle so that it is level with the boat resting flat on the sponsons. This *should* give the best performance, but we'll see. The strut needs to come down about another 1/8" IMHO, but I was at the end of the adjustment and didn't feel like filing the slot bigger until I knew how it worked dropped to where it is first.

Couple of questions though- what mixing ratio should I used? I was told 6oz/gal, but the Zenoah manual says 25-40:1 which is ~3.2-5.1 oz/gal. What are you guys running it at? Also, had any one opened up the adjusting slot on the strut to drop it a bit more, if so- how'd it work? The manual says to raise it for more speed, but that is opposite what I have always done. Yes, higher will let the motor unwind, but that is just RPM, not speed. Lowering it usually brings the boat out of the water more to run looser and faster. What have you guys experienced with this?

king- where do you have your CG set to (how far from the transom is the CG?)? Just curious since it obviously needs a bit more weight up front. Also, as for your speed- you do know that *too* nose heavy will slow it down and hurt it's handling as well, right ?

JakeDW

On your Mboat cooling head is it 1 line in and 2 lines out out?And how do you like it?

Now that I look at it looks to be 2 in and 1 out?

Jake

kwiktsi

Also, does anyone know the size or dash number on the exhaust o-rings? Mine appears to be leaking water inside the boat. Thanks.
Joe

theking549

hey,


jake the cooling head is 2 in 1 out, i loved it i dont think you will find a better one out there.

kwik i tried several things to bring down the bow of the boat down, i glued on rims lead weights on, did not work, installed an iv gas tank in the front, did not work. the only thing that has worked for me is moving the plastic gas tank to the front. i use amzoil 8oz to a gallon, i used zenoah oil and did not like it low quality oil.

to calculate center of mass try this:

1. Find out how much the object weighs.
2. Measure the length of the boat from one end to the other.
3. Start the math. Multiply the lengh by the weight of that object. Multiply the length of the boat by its weight and so on.
4. Divide the total by the weight to calculate the center of gravity for the object.

theking549

kwik your exhaust manifold should be 7/8 and so should be the rings. they should know on the r/c store. if the engine is too lean will run hott and burn the exhaust o rings again.. check your tuning

RKS1949

The numbers are #PRB2695 I just got a set for my hydro,and all the gas Pro Boats use the same set. Hope this helps. RR

rcgod131

garbage its garbage i tell ya

kwiktsi

I bought it used and I know for a fact that it wasn't always in "good tune". I spent time on it today and all seems well now, but I noticed the hull had some nasty black water in it, so I'm assuming that's where it came from. I gotta pull it apart to check.

As for the hobby store and o-rings, I was just going to buy a bulk pack from McMaster since I have to place a supply order anyway, so I need ID, OD and thickness (or any two of the 3 and I can figure the last ).

kwiktsi

Is this really necessary in a thread specifically ABOUT the Blackjack 55? Some people swing hard from WHH's sack around here apparently and anyone who uses anything but gets slammed.. Sure, if I were looking for a more "serious" boat, it wouldn't be the blackjack, but me personally I just needed something I can bash around on the lake when we have our boat out without "too" much money laid out. I have a few electrics here that will clean the clock of most of the guys WHH boats that come here talking smack (hell, they make my blackjack look like the shortbus speed wise!), but that isn't what this is about . This is about the Blackjack 55- pros, cons (however many there may be), mods, tweaks, etc. and I think it should remain that way.

Maybe you can just start an anti-proboat thread and you and your cronies can hang there bad mouthing anyone outside your circle?

R1 baller

Well spoken KWIK, you took the words right out of my mouth

kwiktsi

So, has anyone figured out the best strut position on a stock black jack? I brought it as far down as it will go and have it level with the boat sitting flat on the sponsons. Seems to work well, but wondering if anyone has had better results with a different position. Manual says it is faster if you bring it up, but that makes no sense to me as usually, the lower the prop, the "higher" the hull is out of the water and the faster it will go (within reason). I generally set my cats up so that it is flush with the bottom of the sponsons and either level or with a couple of degrees up angle to keep the nose up. I am also working with boats that are fairly powerful for their weight and size, so I don't know for sure what to do with the black jack. Thanks.
Joe

gdavis9999

This is really disappointing. I was set to buy either the Pro Boat BlackJack or ShockWave, but there seems to be way too many issues, mainly the clutch.

Could the problems be with previous generation models? Most companies make running changes to fix issues. Has anyone purchased a BlackJack in the previous few months and had the same issues?

PEERPSI

My boats just over a month old and the clutch grenaded last night.

kwiktsi

I think a majority of the problems I see with RTR boats like this (aside from slightly lower overall quality) is many people buy them and treat them like they are maintenance free as well. This is not the case- they need upkeep and inspection just like any other boat. If you see the clutch bearing is starting to get rough feeling- replace it. It doesn't matter if it is the 1st tank or the 100th- the bearing can be replaced with a high quality precision perma lubed bearing for ~$9. Don't let it get to the point where it grenades and does even more damage. If you remove and lube the flex shaft after every run like you are supposed to, there is no reason for overlooking a worn clutch bearing- no matter how new or old the boat. Maintenance people- it is necessary .