Nqd Jet Sprint + 22mm ABC Hobby Jet Drive

[damfurst]

This is a build I've been planning to do for awhile and am by far not the first to do it. The hull is the Nqd Jet boat/sprint hull. It can be referred to as the knock off Jet sprint as well since it is a altered copy of Graupner's Jet sprint boat which is very hard to come by and no longer in production at the moment. The drive that comes in the stock boat is a decent copy of Graupner's 19mm mini-jet but has also been altered in suttle ways. The hulls are probably the best Imo that Nqd makes. There are fairly rigid abs and quite tough. If you've watched them bouncing off rocks and such they are suprisingly rugged.

After seeing suckmywakes white knock off with the 22mm jet I became more motivated to start on this project. The Abc Hobby jet drive is probably the best built drive out there. Very solid construction, brass bushings, and already tapped stator for cooling are all pluses. It also means that other than the motor very little modding needs to be done to the drive itself.

So first on the agenda is to open up the brand new hull and completely gut it. I always love this part. This is my second hull and they didn't use as much hot glue on this one. That made it easier to clean up. Also made a second inner hatch out of plexiglass.
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Next I mixed up some 2 part expansion foam and filled the front 1/3 of the hull. Won't sink now.
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Next made a template to expand bottom hole through hull for intake of drive to fit into. Got the drive all fitted in and screw holes drilled. Next will shoe goo this drive in.
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Used an old motor to help get the alignment right on the shaft in the drive so nothing would be tweaked when glueing in.
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[suckmywake]

That looks great. What motor/kv/voltage are you thinking of running? I had to take my impeller out to retighten a setscrew so I snap some pics for you. I hope this gives you some ideas. I cut the Parther 220 down to .858" dia. This dia will leave a tight wall clearance. Since this ABC jet responded so well to my new impeller I tried the same with my stock jet drive tear into with an x432 with little luck but still trying. I think I will next detongue the blade on the x432 for stock jet.

[wakeboardfusion]

what is the third picture of? some sort of intake grate?

[LarrysDrifter]

Its a trim tab.Where the plate gets small on the other side of the screws is where the water pickup is for the jet.

[damfurst]

what is the third picture of? some sort of intake grate?

Larry is right some call it a trim tab but it's also known as a ride plate. It fits underneath the nozzle and the stator coming out of the back of the boat. This not only helps stabalize the boat but also protects the stator and nozzle when jumping over things, logs, rocks, other boats, etc.

Thanks for the pics suckmywake. I'm going to give cutting down the prather 220 prop a try. Your ride plate also looks good. I may have to put one on this boat.

[suckmywake]

Video from today at the pond. After the bigger boats broke we sent the jets out to play.

I think you will end up needing a ride plate. My boat likes the ride plate bent up close to jet nozzle. If you look at vid around 49 sec you will see my boat bouncing. I was doing some testing running the boat without the ride plate just moving batts (3s 2200mah) around to change cog. The boat runs much better with ride plate with one batt along side of the motor and one across the hull in front of motor. I have wanted to try to cut down the area behind the intake and fill in with JB weld like sundogz does on his ABC jets. I think if I could keep jet prime I could get more speed out of it especially during turns.

[wparsons]

Do you know of a reliable source for the ABC drive? I haven't been able to find a source for one yet.

[suckmywake]

They are getting hard to find. I got mine in the ABC Hobbies Jet ski a few years back on ebay. I think I paid $36 for mine. I dont think they are in production any more. They will pop up on ebay but $ high. One was on ebay last week for Buyitnow $200+sh. I did google and found this site that claims to have them.

https://www.rtrhobbies.com/Products.aspx?CatID=50&CatCode=BBE&ProdID=170773&ProductNumber=ABC58901

[wparsons]

Too bad they don't have just the drive!

[damfurst]

Finally made some progress. I am using a 2848 3900kv inrunner to power the drive with a 60A Turborix esc. This motor has been used by sundogz on his jet skis on 2s which is what I plan to run it on also. I may try different motors later but initially this will be it. The esc has already been waterproofed with epoxy as well as the tx. So got the motor, esc, tx, and servo all mounted. The servo is nothing special just one out of a jetski dipped in waterproofing rubber. I ran the cooling lines to the water jacket on the motor too. Next I'll do a tub test and check for leaks.

[damfurst]

Maiden voyage of this boat. Video is short and shows boat at 1/2 throttle most of the time. Problem with cavitation and loss of prime on rougher water at full throttle and I need to change a setting on the esc. Overall I liked how smooth it was. It also wasn't screaming all the time like my 19mm one does. Next will try screening the intake to see if that will help any and also try forming a delta in front of the drive.

http://www.youtube.com/watch?v=2OlRNzSt_-E

[suckmywake]

Was the vid with stock or upgraded impeller and with or with out ride pad? Are you thinking of heating up the abs in front of intake and bending up the keel to form a flater bottom before intake. I know what a delta pad is but don't understand one in front of jet intake. Will you please post pics of what you had in mind or after you do mod. Thanks

[Jesse J]

you guys have convinced me, this is my next boat... might be my first RTR as well. I see Newegg has em for $45 shipped... is it the right one?

thinking its time, plus it might look good behind my scaler riding around on a trailer... get it? scaler trailer.. anyway, they say its 1:25th scale?? looks a little bigger. I may be trying some of these ideas later, haven't ever owned a jet boat.

[marko500]

Just picked up one of these jet boats off ebay last week. Thinking of trying that little 3000kv Mystery outrunner I got from you Jesse J quite awhile ago in it. Fits up perfect to the stock jet unit.

Mark

[damfurst]

Was the vid with stock or upgraded impeller and with or with out ride pad? Are you thinking of heating up the abs in front of intake and bending up the keel to form a flater bottom before intake. I know what a delta pad is but don't understand one in front of jet intake. Will you please post pics of what you had in mind or after you do mod. Thanks

The vid was with a stock impeller and no ride pad. I do plan on doing the impeller mod like yours with a Prather 220. Yes I'm going to try to put a delta pretty much as you described and I will post pics of this.

Jesse J :you guys have convinced me, this is my next boat... might be my first RTR as well. I see Newegg has em for $45 shipped... is it the right one?

Jesse Yes that's the right one. You'll be modding it before too long after you get it. The brushed motor in them don't last all that long. We should get together once the ice is gone of your water. Let me know.

Marko500:Thinking of trying that little 3000kv Mystery outrunner

That motor is perfect for the stock drive. You can run it on either 2 or 3s with a 30a esc.