A problem with my HobbyKing Pulsejet 

I have no doubt that you will have it sorted out in no time. It is always a pleasure watching you work, and you are at your best when products are at their worst. So, secretly I hope for problems because of what I will learn from watching you make it right. I know, I'm bad!

Bruce we are in the same boat. If there is one DUD in a million I`ll get it. If anything can go wrong it will go wrong on me. Just last week I used the US postal to mail out a package to Houston Texas from my house in Brooklyn, NY. Don`t you know a week later I received the package back at my door as if I mailed it to myself. No explanation No apology, I had done my part properly. I had to re mail it and they would`t even express ship to make up for their mistake. If things can go wrong they go wrong on me ! I`v had this black cloud over my head my whole life..Cheers

Excellent,liked how you explained how the fuel and air are mixed,learn't more from watching your video about the Pulsejet,than i ever did with google!,thanks you obviously know your stuff.

I have had the exact same problem as you, the fuel was pouring out the front, eventually that week air injector broke off. I used a huge air compressor too.. Really bad QC at HK with this product. I had big plans too. Looking forward to seeing you're run mate.

Bruce I really love your videos...so helpful as well as entertaining! Did you ever post a video of the pulsejet after it was fixed? How did you make out with Hobby Kings turbine engine? I didn't see any videos after your second one on that subject and wanted to see what the end result was!!!! Thanks again for all your hard work and teaching us the things we need to know!

Goodonya Bruce - your misfortune is our learning. Thanks for explaining what's going on. It helps n00bs like me understand things better. I haven't fired mine up yet, so this is all good info. I might wait now before I 'maiden' the engine - see what else you might have to say about it. Thx again, Q:)

I will bolt one on a Control Line & go fly tomorrow.Will put on you tube to point out everything you need to know.Some points of fact are Pipe is .5mm thick.Bailey is .35mm.OS is .45mm.Pipe is a bit shorter in length in chamber and total length.This is OK,Just means less power than the others.Head & reeds are perfect.Frojector has bad weld & a copy of Dyna jet & OS pulse jets.Use a Bailey Sport Jet flowjector.Buzz Box is only good for Barbecue.And use Methanol to protect the reeds & help starting.Just drill out main jet to 1.6mm

Ohh Bruce, i feel sorry for you! You are helping me, and a lot of other people, out! I hope this will come to a good end!

Hope you get it sorted.

I don't think you are alone with this problem, Bruce. Here in the UK RU-vid poster ThatHPI GUY also has had problems with the air "flowjector" assembly as his broke off due to the brittle construction on his example. Regards = Nidge

Hi Bruce. Good video. I had the same problem with mine and it's definitely a fuel feed issue (or lack thereof). I was able to start successfully by spraying engine starter fluid into the intake. Further, only when I raised the tank so the fuel was level with the flowjector was I able to get a good start and run. it didn't take much air to start it once I did these two things. Thus, I feel the flowjector isn't doing a good job of providing fuel. It's not creating a spray. It's just spitting fuel out and not misting it. Hopefully it is due to the angle as you pointed out. One other thing - when applying air to the front end, rather than directly through the flowjector, the fuel actually gets blown back up the fuel line... Venturi effect isn't working right. Perhaps the flowjector isn't situated at the correct point inside the venturi. Regards from Canada

I turned the flowjector around so the air nozzle was on the bottom (pointing up). That way I was shooting fuel/air up towards the spark plug. It was much quicker to start this time, but still takes a bit to get going. I'm sure this flowjector isn't misting the fuel properly. On a side note, a confused neighbor down the street came outside. She thought the noise was her hot water heater blowing! Good times.

did you ever get this working. I watched the Pulse Jet reveiw part 1 but could not find any updated videos.

Me too - it's just dribbling out the front (a common complaint in my family). I found that by holding a gas lighter at the outlet I could ignite the fuel/air mix there, and by reducing the air flow, the flame would travel back into the engine where it would occasionally burp. This showed me two things: there is SOME fuel getting into the chamber and it's not being ignited by the plug. You have given me something to work with anyway. Maybe grinding away the stop on the injector would enable it to screw further into the intake?

By any chance are you still selling your book on pulse jets? If so how do I contact you?

guys, whilst we may think giving bruce advice might seem helpful, remember that he builds these things. just a thought

This guy is good. What a great diagnosis!

Are you from New Zealand? Sorry if my guess is wrong, as I know Aussie and Kiwi accents are similar but, on the same token, fairly different from one another.

Have you tried to put pressure on the intake to? If there will be am air flow the fuel wont backwards.

Bruce did you get your HK Pules Jet to run yet?

If you slide a solid steel rod through a hobby king engine you can use an English wheel and a metal forming hammer to make the oval shape exhaust pipe round.

Hi Bruce just checking to see what psi you are running on the compressor as we have found 55-65 psi to work best. also the holes in the flowjector needs to be at 1200 & 0600 some reason they don't like being where you have them.. regards Robert ( kiwi jet squad )

I have the same experience, will dismantle and try to correct

Bruce I found it really helps to have the starting air track angled at the spark plug. I can start mine with a bike pump if im out at the field.

Please finish this review Bruce! I want to hear her run :-)

I suspect your Pulsejet is in working order. What is not in working good order is your startup protocol. You are using a air compressor that seems to compress air quite well, but has a very low flow rate. Your high pressure low volume air results turbulent flow, which is blowing your fuel back out your intake. The pulse jet does not need high pressure air, it needs high FLOW (low pressure high volume). Next time use a leaf blower with a narrow tip outlet to increase the velocity of air. Keep the air flow axial to the jet until the jet glows red before removing. :-)

does the fuel line need to be pressurised or can you just have a resevior?

I had the same problem with my HK PJ and checked the Flowjector with the known prints for a DynaJet and the 35 degree angle on the prints is were my Flowjector is set at. Also checked the hole sizes and there location per the prints. All is on. I did a search on line and found what noclassmac1972 said to have the openings at 12 and 6 o'clock position. Also fuel level in relation to center line of PJ is a issue, Move the tank around. Also here in South Eastern Washington State (USA) it has gotten very cold here 19 Degrees F at day and a over night low of 10 F. I preheated the PJ engine and it fired right up. I have 3 more HK Pules Jets inbound and a extra Spark Box. I also elevated the front of the PJ too. Bruce PLEASE DO POST WHAT You find out on your PJ. Again thank you for your video on how to make reed valves. I have spring steel and SS plate inbound to me. People please keep posting what you find or see right or wrong with HK PJ. We are a world wide R&D team for good ideas that are just not tested very well before they are rushed into production.

I found with mine if you position the air feed at the bottom so the air fuel mix is blown through the petals into the spark plug it fires up easily , also you only need a fraction of the air you are putting in it all that seems to do is hold the petals open, mine starts and runs easily now

I had similar problems with mine but sorted it out by (a)sealing the threaded front part with exhaust pipe assembly paste as fuel was clearly leaking past the threads,(b)pre-heating the tail pipe and combustion chamber with a blow lamp and (c)raising the tank height so that on starting, the fuel level was just below the centre line of the engine.All was then fine and the noise was ear splitting....!!

What if you raise the the front part, so the fuel will flow to the combustion chamber?

turn the fuel can 90° so that fuel gets to the line into the engine ?

Bugger! Guess that's why I love electric gear, even though I'm still an electric newbie. Fingers crossed you get it going Bruce. Great info btw

bruce, had exactly the same and i think it has to do more with the sparkplug been to far forward, by the time the fuel is coming out the front it should have long fired..... here is what i did : turn the engine 90 degrees so that the sparkplug is at the 3 o clock position ( viewed from the front ), then turn your inlet that the air nozzle blows in from the 9 o clock position ( viewed from the front ) - what this does is that it takes the fuel air mixture and actually blows it across the engine combustion chamber towards the sparkplug. I use cleaning benzine and it fires imeadiately when the fuel hits the fuel nozzle, no hesitation at all... If you compare it to the original dynajet motor you will have noticed that the original has a different sparkplug postion... try it and let me know if it works... oh yes, something else - when you tighten the flowjet be careful not to bend the lineup during assembly, it is supersoft...

At high speeds, air is going to push the fuel in, try blowing with a leaf blower when you try to start it.

Seems to be a big problem getting these started, the only thing I noticed that you've done differently to others, is that you have yours flat/level. Just a suggestion, if you haven't already, try raising the red head up 10 degrees or so just for ignitions sake. Never know, may start it and once started, maintain enough power to draw air/fuel through by itself. If not, then defo looks like HK are becoming box pushers. Good vid/review anyway.

The problem is that it's from Hobby King.

no entiendo muy bien el idioma, pero logre entender donde fue el error de inclinacion para inyectar el combustible. gracias Walter White!

I built several pulse jets- Crazy Loud and Hot -huge flame at night - 14 pounds thrust -

What if you put a starter fluid will it work?

Hello friend, I bought one just like yours, and the same problem is happening, it does not power up, what should I do?

I have found so far the Basics of the Jet are perfect.Just the spark plug & buzz box to basic & flowjector is best modified for Methanol use.If nothing else set up the flowjector for Methanol.

Good old Hobby King quality control! The place where if you need 3 servos, buy 6 and hopefully with a 50% dead on arrival rate you will get 3 good ones ;-)

Thanks , now i know why mine only farts .cheers

Nightflyyer had some success with his.

Hey Bruce, I like your work around for commenting since Google screwed up everything. Log into your other account and post as a viewer. Brilliant!

Looks Like you bought yourself a rather spendy but very nice looking box with some scrap metal inside LOL. But seriously Bruce I do hope you get it sorted out and you should do a video of the fix so you may be able to help other people out that are having the same issues starting the knobby king pulse jet. Regards, Pete.

You'd think that Hobby King would know your name by now and send you the good stuff so it makes their products look good.

I have built a pulse jet similar to this one called a pulso kriz 1 but I can only get it too run with forced air it stops as soon as I remove the leaf blower would anyone be able to offer guidance? I would be extremely grateful

mine is doing the same thing. it ocationally pops.. but will not run.. I can but excess fuel in it and it pops. I was thinking the same thing.

Put on glowes next time, you are not to Old for that, besiddes tha t I love your whiteboard videos. You rock mate.

Wow. That sucks. I saw NightFlyer also picked one of these up. He was having all kinds of issues starting his as well. Maybe it's the same issue.

I could have gotten it started. I did this 50 years ago. It's too lean. The level of the fuel is critical. Too low = lean. You're fuel level is way too low. You can see it in the video. That is, you can see the fuel running back into the tank every time you stop with the air. It popped a couple of times. If the mixture is right, one pop and it's running. Another inch of fuel in the tank would have gone a long way towards success. I guess I'm more of an expert.

Just by looking at it, the fuel level is way too low the level of fuel needs to be just under the the flow jector and maybe the reed valve is stuck when i got mine it wouldn't start, cleaned the reed valve and fired right up I have also found that the best fuel these run on with the standard flow jector is shellite.

im thinking the valves are a little too stiff.

Check NightFlyers video on his. It took him three days to get his to run.

That's the best T-shirt you could find to represent New York City?

What's the fuel consumption?

As you're saying the air is blowing to the wrong place. But you also have too much air pressure! Your sucking too much fuel to be able to light up the fuel vapor in the burn chamber

Typical HK quality, get her fixed Bruce. You can do it!

maybe try arranging it so that the air adapter is in the bottom, maybe this will prevent the fuel getting spat out "maybe" by "gravity"

I accidentally broke my injector on my Hobbyking pulsejet.. well the the part of the injector that's shown on the video as being the wrong angle.. I snapped it off whilst screwing the thing in! But, must have done me a favour as I just blew air into the jet using my compressor and fired-up ... ok to awhiles to catch but now I've seem this video I've a better idea at the angle to point the compressor gun at!! Btw, I think the parts are too delicate to weld, it may be a case of soldering instead. Anyone know if there's gonna be spare parts available from Hobbyking at some point?

Bruce, couldn't it have been an issue with the pulse valve itself? If the valve is too stiff or not properly calibrated, then air and fuel are just going to push back through that intake port.

Bummer ***** but kibd of expected it not to work as seen with others so far, even Dave Herbert had problems with his too, also ThatHPI GUY had his injector snap off :-)

start of the fuel flow is wrong? why don't make a backup fuel line (ONLY FOR THE FIRST PUSH) to the combustion chamber? give fuel to the chamber, spark it and the flow should start the engine

You didn't actually expect china to know how a pulse jet actually worked did you? They just copied a photo!

I've got one and the build quality is much better then this one and it starts easy and runs well!

HobbyKING, THERE IS YOUR AANSWER

Bruce, have you managed to repair the HK pulsejet yet??? BTW... HK new has reed valves stocked at a cheap price. (PRODUCT ID: 171000407-0)

There is a video with that PJ on a funjet. It leaks like yours does but it starts. Here it is /watch?v=t93KmnNtWv8

I had the same problem. Try rolling the spark plug around to the 5 o'clock position. This helped wet the plug a little better for ignition. Also test the sparkplug. Sometimes it will spark within the confines of the space between the electrode insulator and the thread instead of across the gap. This shrouds the spark and prevents ignition.

i dont know if you watched nightflier, he says you need a serious compressor

Are you sure you are connected right and that your air doesn't go to the center and fuel to the outside connection. I have made and used a lot of Ventura's and most of them air is injected in and creates a vacuum behind the air source and pulls fuel in and forces it into the airstream. From your drawing it looks to me like the air would be in the center and fuel pulled in from behind the air source. I could be wrong but I wasn't moving fuel with mine. I use to build them to move plastic pellets from plastic grinding equipment up into a hopper on an injection molding machine but the principal is much the same. I know that basically if you introduce an air flow in a tube just beyond one end that a vacuum is produced from one end up to the point that the air flow is injected and anything in that vacuum is pushed past the airflow injector and out the other end quickly. Good luck.

Hobby King strikes again!

Mine is doing the same. I assumed it was a problem with my fueltank

could be the reed valves not opening.

Btw fella... if and when you come up with a solution on how to make starting this thing more reliable, let us all know ! Cheers

How the hell does this thing work? Is it a jet engine with no moving parts?

LOL checkout the nightflyer Dave video trying to start his

I'm a noob to pulsejet and anything that uses fuel in general, but perhaps its because the fuel line is above the actual fuel? Try flipping the tank over so that the fuel is pushed down the line with gravity :)

With all the water you were blowing into your pulse jet it's no wonder it wouldn't fire up.

Well, obviously you're supposed to start the engine standing on it's tail so the fuel dribbles down into the combustion chamber. ....

Tighten the locking ring

oh sh...t.,,,,,,,, I order my engine before to see you review

try using propane / butane as a test fuel.

Paging Colin Furze - pulse jet fault finding required

good white-board explanation ! ; P

Check out NightFlyers video on the Pulse Jet

Check ignition

These Hobbyking Pulsejets are rubbish, they are literally a toy. The problem with these is they will break along the welded seam along the engine length. They can't withstand running static for more than a few seconds before beginning to melt. A trick to starting these is to start flooded, a flame at the exhaust will start the ignition cycle and the fuel level is critical when starting. Air can be just blown into the reed valves to start the air fuel mix. I can see from this yoru fuel level is way too low.

Now we know why the Aussies didn't try to take over the world.

"Says sarcastically" Hobbyking having problems with quality control? noo

Try try again. Cheers.

You and me! if it's broken I get it!~ :-(

If you are using glow plug fuel, it won't work at all :-) LOL ! A pulse jet goes with unleaded fuel or petrol, not glow plug fuel wich need at least 4HP compression to explode/ignite... Also, more than 2 bars (around 30 PSI) is a lack of understanding. I can clearly listen that you are way over the lauching procedure....

I wonder how's the guy from Britain WW2 era hear this

sounds like a stuck reed valve

Nah, you can't be that unlucky with the duds. The HK ratio of good to bad is well skewed towards the latter as far as I am concerned. I recon that I get just as many duff items as yourself. This pulse jet looks great, which its meant to be so it sells, and despite it's problems, in your hands its probably relatively safe. However in the hands of the unknowing and unwary, something that's playing up like this is a disaster waiting to happen :-( ................... Just look how the unexpected thrust caught nightflyer out when it did finally start up and the speed at which the tail pipe went into superheat mode. Hmmmm.

All of these videos of at home pulse jets are all good and well. But there isn't a single at home version of a pulse wave detonation engine. I realize this is something only high class university and military contracts have created but can anyone else do it?

Are your glasses broken?