I just recently got a hobbico(aquacraft) nitro hammer second hand. I am having some problems getting the engine to run right. Could some one help me with it? First is the needles, what are the factory settings or how should the idel mixture need look like at wide open throttle. once it starts, it bogs down with you give it full throttle. IT also sometimes at idle will race really high even though the throttle does not move. Also the tabs on the back, do you bend them up to ride higher out of the water, or opposite? Also what are some good mods you all would recommend to it? Thanks guys. I would greatly appreciate it if you could help me.

Well, I can help you with the tabs. They are called treim tabs.
If you bend them up, the nose of the boat will ride higher.
The idea is, if the bow of the boat is "porposiing" or bouncing up and down, you will want to bend those tabs down(evenly) till the bow of the boat stops porposing and boat drives smoothly across the water.

As for engine tuning most engines, as I recall, seem to like to start out at about 3 and a half turns from fully closed. Then the motor is tuned to a nice high pitch at full throttle. I have no other idea how to describe it. There are also set screws that will set the max and minimum throttle on some engines.

I hope you can get more help than mine on the engine settings.

thanks umi. is that 3 turns from closed on the idle mixture needle?

It sounds like it is running too lean. The high revs at idle is the clue and bogging down in the water. boats have to be run slightly rich on the land then when they are put in the water, the load of the prop will lean the motor out. This can and will change day-by-day and sometimes in a few hours.

Thanks Umi for turning me onto this site.

hey guys thanks for the help. I have some more questions. How many shims should be under the cooling jacket? I had 3, is that to many? Also it seems like it is not sealing. I have my boat sit for a night and there is an oily residue all over the engine and hull the next morning. I did have some fuel in the fuel tank, but I don't know what is leaking.

one more question. i took off my cooling jacket, and it came in two pieces. What should I use to seel the two back together? Is there a gasket or use some kind of automotive sealer? Thanks.

There is no cooling jacket on the Nitro Hammer, is there?

My Hammer's idle mixture screw is about 1.5 turns from closed. My high-speed needle valve is set about 2 turns from closed now. The manual and video says to set the high speed needle valve 2.5 to 3 turns out from closed then lean it out till it's tuned and leave the idle screw alone. You can download the original manual here:

http://www.aquacraftmodels.com/downloads.html

If your boat is second hand I imagine it's already broken-in, maybe not correctly though. You'll have to play it by ear until you get the hang of it, also try turning the high-speed needle valve (left side of the carb), counterclockwise a little at a time until the engine doesn't bog down when you hit the throttle.

IT also sometimes at idle will race really high even though the throttle does not move

on my cd thay start the boat with out it raceing really high.
I fixed this bye ajusting the link on the carby so it would close more and now it doesnt race as you say.

Originally Posted by MattBar313

I just recently got a hobbico(aquacraft) nitro hammer second hand. I am having some problems getting the engine to run right. Could some one help me with it? First is the needles, what are the factory settings or how should the idel mixture need look like at wide open throttle. once it starts, it bogs down with you give it full throttle. . Also the tabs on the back, do you bend them up to ride higher out of the water, or opposite? Also what are some good mods you all would recommend to it? Thanks guys. I would greatly appreciate it if you could help me.

I´we made some mods on my nitro hammer, i changed the rudder to a CNC cutt aluminium one with built in water pick-up, changed the power switch for the radio to one that´s water proff, changed the mount for the antenna to one that´s more stable and water proff and i drilled two holes in the deck to give the engine more air.

I´m wery pleased with my nitro hammer after these mods, especially the rudder since the original one is crapp and brokes WERY easily.

Somemore mods are on hte way, an octyra berylium propp, new 4mm propp shaft with M4 threads (standard are 4mm with M3threads), a better exhaust pipe and maybe a .18-.19 engine.

Here´s a shortmovie clip of my nitro hammer before the mods

Running my aquacraft nitro hammer 2 (0 min 26 sec)

.PS. I hade some problems with the engine thats simillar to the ones that you describe butt it was the low-speed needle that needed some adjusting.

A good tip for the nitro hammer is to cut a hole in the hatch just above the main carb needle, it make adjustment so much easier.