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Trouble Starting Your Nitro Radio Control Engine?

Let Our Guide Help You With Starting Problems


Nitro EngineHaving trouble with starting your Nitro engine? Frustrated that everything you try doesn't seem to work? Try my trouble-shooting guide to see if it works. I've picked up plenty of hints & tips running in Nitro cars, HPI & others over the years, so maybe it will help. Always remember to consult any instructions or directions that came with your car first, then try this FAQ.

Ok, first thing to check is that you've put the right fuel in your car. This is the most common problem for beginners, who try to use a more powerful fuel than is recommended by the manufacturer, in order to gain more speed & power. The problem with this is that engines and carburettors are designed to use a certain grade of fuel, and any deviation from that leads to starting and tuning faults. It is possible to use higher grade Nitro fuel, as long as you are ready to re-tune the engine and be prepared for extra wear. If you do change fuels, keep using that one, or your car will become unreliable. In summary, if it says use 16 Nitro fuel on the box, use it!

Still won't start? Next up is your glow plug - is it getting hot enough to ignite the Nitro Fuel in your Radio Controlled Car? A faulty glow plug, or a flat Glow starter will mean no starting! Take the Glow plug out of the engine, plug it into your GlowStarter and check that the Glowplug shines nice and bright orange. If it doesn't glow then you could have a faulty glowplug or a flat Glow Starter. So always keep a spare glow-plug in your track-side tool box, and your Glowstarter charged. (Or a spare, charged Glow starter!)

If your Radio Control Car still won't start, next up we've got to see if the engine is getting any fuel. Is their fuel in the tank? Next we've got to look inside the engine. We do this by pulling the air filter out (put it down somewhere clean) and looking into the carburettor. Push the Fuel Tank Primer and you should see Nitro Fuel going in. If you don't, there's an air leak somewhere in the system. Check the fuel tank and pipes and order any spare parts required.

Still not working? Maybe the air filter is blocked. Give it a good clean and re-oil with cleaner and air filter oil.

Next if your motor still won't start you'll have to put the carb back to factory settings and follow your Nitro engines set up guidelines.

Still no luck? Maybe the one-way bearing is broke. This is the part that makes the engine turn in the right direction, so take out the glowplug, look into the cylinder head and slowly pull the pull-start or operate your rotostart. If it doesn't move the piston, its broke.

if you Nitro engine still won't start my advice would be to take it to our local model shop & get the to give you a second opinion and advice on what to do next, probably a new engine, but they might be able to help.

Thanks for reading!

Comments / Questions:

hi i just bought a hpi rush evo off my friend and he didnt use the car all that much, it still looks new condition but the mixtures have been fiddled with, it starts eventually after alot of pulling and blisters on your fingers but then when it stalls it wont start for ages again, there is fuel getting to the engine and the glow plug is running fine, the fuel is good still is it just the mixtures?

Probably, check the manual, but also find out how old the fuel is, and get some new if it's over a year old.

iv got an acme size 18 engine and i was wondering how i would know if my clutch was warn out.

The engine will rev, but you'll have poor acceleration, if any.

Hey, iam am having trouble with my HPI RTR Nitro drift car. its just new
Its starts alright but the second i take away the glow starter from the glow plug it cuts out even when throttle apllied. it runs fine when glow starter stays in. I have tried adjusting the idle trust and carborater screw hour upon hour, but still no luck, just cuts out. There is also another screw under the air filter, what does this do?
Reply much appreciated.

I haven't worked on one of them - but it could be that the throttle linkage from your servo to the carb is set up wrong. Make sure your car is off the ground so the wheels can spin freely, then pop the servo linkage off (or just make sure the electrics are off). Now take the air filter out and look down into the body. Put all the carb screws back to factory settings. Adjust the idle screw until you get a hole as per the instruction manual, put the filter back in and fire her up.

Take the glow plug off, and see what happens. If it stalls, try opening up the idle screw a little and try again. You should get to a point where it runs without the glow plug. Now re-atatch your servo and turn it all back on.

Of course the above relies on the fuel being correct and their being no other faults - check for air / fuel leaks, etc.

My buddy bought a Savage X because we have had so much fun with mine. I've had it about 2 and a half gallons(6 months) and it runs like a bat out of he--.I have just about beat the living snot out of this thing but always monitored the temp,(with onboard temp guage Venom)
After talking with some of the Race guys they say break in should be 5 tanks of fuel some 10 tanks I broke my motor in the book way and 2 tanks idle one slow fig eights.
Woody gets his truck, breaks it in 2 tanks idle 2 tanks slow eights, 2 more tanks at no more than half throttle(just to be safe) then we started to tune after 2 more tanks we got it to where it was flying.Then on our 3rd day suddlenly after a few passes to tune, the truck stalled and we have yet to get it back on track.
He e-mailed the question When the truck starts idles fine,but when giving gas it stalls he checked for leaks and none. You informed him to take it back to the hobbie shop where he bought it.
The hobbie shop guy turns the high needlw in about half way and says its good to go. We take it  out and run very cautiously check temp and it was at 305 degrees???. We tried to richen it up and it stalls. The only setting it will run at is this super lean setting . We know this is not right.Could it be that the motor has broken something? Like I said my truck I have beaten unmercifully and it like the abuse. Woody  however would rather sacrifice speed for duration.
No leaks, Good fuel, new plugs, fresh filter.
Where do we stand on waranty,Parts defect.
What should my hobbie shop owner be doing Besides leaning the motor out to explosion temps???
Iknow this is a long question but anything u can advise us to do would be great. Jesse.

Contact hpi and ask the experts.

This Woody with the savage 28 X took truck back to shop they told me I didn't know how to tune I try to exsplain that I had this truck break dancing it was running so good at low temp.left truck at shop they called me said truck was ready picked up took home tried it high speed niddle was cranked in so far 2min running I was at 340 deg not good.Took back to shop was told I didn,t know how to tune told dude I didn't want any thing for free just wanted truck fix so I could play  call 5 day later took truck home ran the same way NOW remember I taken this engine apart pulled the sleve piston crank filed buffed polished and put back and sealed carb back plate before taking to shop to try an fix myself what I never looked at and don't know why I did was the exhaust pipe . I opened this pipe up and said what the hell is that stuff in there I happened to have a spare checked it out it fas clear put that pipe on the truck tryed it and felt like a little kid at xmass time the thing went crazy it never ran so fast I ran it for a tank fliped it about 100 times stalled once temp never got over 200 .Having problem running never forget to look inside the pipe don't just blow through it look in it.WOODY.

Thanks for sharing - sometimes we miss the obvious.

Hi there, I have a bv1 with a o.s.15 motor that won't take off from a standing start at full throttle, it just free revs. But if apply the throttle more gently it can build up to full speed. Is this a clutch problem? Thanks, Adam.

Sounds like it.

iv got a colt 1.16 buggy . when i try and tune it in i put it on the floor and it runs for a few secs then it cuts out . but if i hold the thing it will run for ever . any ideas? pls help. Adi.

Go back to factory settings, then start the tuning process again, sounds like its running too rich / lean to me.

got a savage 4.6 idle fine starts fine as soon as you give it gas it dies I took carb apart and cleaned it looked good check tank and lines for air leaks seams tight I checked for air leaks put thumb over air cleaner opening and blue in to fuel feed line into carb with a freash peice of line its tight till I open up the carb the more I open the carb the more air leaks out is this normule I ouned the truck since new broke per breakin pluss a few tanks and ran it for about two gal of fuel ran great always keep temp below 275 most time at 250 whats your though thank you for any help you can give me. Woody.

Take it back to the shop where you bought it and get them to look at it. Please use punctuation.

hi... i bought a T15 HPI engine and it just wont start. I've set everything back to factory defaults and also changed the glow plug to a O.S. No.8 but the engine just wont start at all... what else m i missing? Im using the Trinity Monster horsepower 25% Nitro Fuel. Rick.

Isn't the T15 rated for 16% fuel? Also check that your fuel tank is priming correctly.

i have a pico .28 and gas isnt gettin to the engine i tryed changin the fuels i checked the caborator and it still isnt gettin fuel HELP!!!!!!!!!!!! MY CAR IS MY LIFE. Jervon.

Check your tank / fuel pipes for leaks. Do you have a primer tank? Is it pushing the fuel to the carb? If not, that may need replacing.

have a t-maxx with a .18 engine and i run it on 25% nitro i tuned it and the glow plug blew out i have ran it in properly. Ali.

OK, what's the engine meant to run on % wise? Stick with that. It could be simply that the thread on your plug or engine block is damaged.

hi can any one help im haveing trouble with my .18 nitro motor i cant get the tickover right and it stalls on the break not sure if my clutch is set right or mixture is ok can enyone help
regards john.

You want to start by adjusting your idle screw.

i have a revo 3.3, the glow plug keeps burning out, i have replaced it about 10 times now, and they arnt cheap! £4.50 a time. does anyone no how to stop this from happening?

First up always keep your air-filter clean and oiled, and check your fuel tank for dirt, this will kill plugs quickly. Try a different brand.

Hi I have HPI Savage 25 (stock) bought it used was running great now the engine runs well but when accelerator is pressed the truck does not take off, just revs normally and goes nowhere.

When in reverse it works fine same torque as usual.

I'm new to the hobby and can't figure out what part(s) I need to replace

I'm no expert on Savages, so take all this with a pinch of salt, sounds like its not changing gear, and / or your clutch needs replacing and its slipping. I'd look at the clutch first as the slipper ring is pretty cheap to replace, consult your manual for the part numbers.

HI Can you help i have a rush evo, the engine just stopped one day and i left it for 2 years, i have been getting it running again but it is a real pig to start, i have set the carb back to the base settings, and fitted a new glow plug, it takes about a hour of pulling before it starts, it then runs rough but if i keep the revs on it will stay running, but if it stalls iam back to square one, as it wont even start hot and then takes ages to start again, it has not had much use, and the engine still looks new, hope you can help Thanks Neil

Take all the carb settings back to their factory defaults. Make sure you're using fresh fuel. Check all your fuel lines and tank for leaks / cracks. Check all the engine mounts to see nothing has come loose. Keep trying!

hey there, having a little problem with my high speed needle.
I've had my firestorm for about 2-3 months, when i got it i was very careful with the break in and didnt start tuning it until i had ran a good 7 tanks through the system.

3 months on and after using it every sunday since when i brought it I have purchased a new O'Donnell 16% fuel gallon. I have spent hours on my engine and setting up th idle and breaking, it is perfect! :) but recently I have had trouble with the high speed needle. Whenever I go to lean it out a little bit as soon as i run the car a metre it stalls :S there is quite a bit of smoke coming out of the exhaust and its confusing me a tad as usually you loose smoke as you lean it out :S ?!!
please help us out as i really want to tune the engine properly

Is the O'Donnell fuel a different make or brand than the one you ran the truck in on? If so, that may be your problem, take the carb back to factory settings and tune it again.


Ok, you may have an air-leak somewhere, so change all the fuel line first. If that doesn't work, jave a real good look at the tank to see if has any cracks, or maybe the seal on the filler has perished, if so, get a new tank.

Put the engine back to factory settings and go through the run in process, gradually tunning it up.

hi i have a MMGT 3.0 and whenever the fuel in the tank gets to half tank the engine cuts out. I have bought new fuel lines and adjusted my carb and this still happens. Also when im running it i will hit the brake a little bit to slow down and in cuts out. Any suggestions? Ryley

Same problems affected quite a few of the early Savages - either just run with half a tank all the time, or change the tank.

hi there i have a nitro rc car t-15 engine. everytime i pull the trigger back to get it moving it only revs it doesnt move any ideas?????

Sounds like your slipper clutch is too loose or worn out, they're cheap and easy to repair, see your manual.

hi my car and everythings fine but wen i start it my car just shoots of so what do i do ... do i hold the brak but when i let go of it it just shoots of at full speed reply ASAP thanks. Devin.

Your idle screw is incorrectly set. Check your manual.

my RC car starts fine then when i go to throtle it the back wheels spin when the cars off the ground but when i put it back on the ground it wont move and the cars only like a day old and i have broked it in like they told me wat could be wrong with it?? Chloe.

Its just not tuned correctly at the moment and needs more running it. Change the settings back to the factory ones and start again. Don't worry, all of a sudden the power will come and the car will be great.

can you bump start a hpi MT2 roto start. and if you can how .  because iv been having trouble with it iv changed the glow plug and checked the fuel lines and the engine still wont turn over ???

I've never tried it - is fuel getting to the carb when you prime the tank with the plunger? If not, you may need a new tank.

hi there, ive got a rush evo and it starts fine but when idling it revs to full throttle and then stalls WITHOUT TOUCHING ANYTHING. I have set the low and high speed needles back to base settings, but I aven't put idle needle back to base (don't know what base setting is for idle needle). I think its the idle needle setting, it could be set to lean but I've already had a go at changing the setting. Any way cheers, perhaps you might know a solution. Alex.

Check your manual, and you'll see where the idle screw is. Pop out the air-filter and look down into the carb. As you adjust the idle screw you'll see the throttle opening and closing, see your manual for the gap, its normally pretty small, too large and the engine will race (and the car shoot off!).

my nitro truck won't start when i pull the pull start the fuel is not moving through the tube so there it no fuel getting into the engine so it won't start. plus it is only a day old what should i do. ian.

You need to prime the tank first - push on the plunger if its got one, then you should see the fuel moving. If it doesn't, there's an air leak somewhere.

hi there right got a pro 12 engine and i built bye mags and the car running fine but every time i put break on it stops the engine any ideas do you think it is clutch not working please help me. Andrew.

Its idle speed is too low, or the clutch is incorrect. Start off by increasing the idle speed and see if that works.

the car turns over, but goes straight to high rev's and wont slow down?? any advise? Phil.

It could be because your throttle is set too high. Consult your manual and find the reference to the throttle limiters. It could be that you idle screw is incorrectly set, meaning that the engine can't physically slow down.

Also check that your r/c transmitter hasn't got the throttle reverse switch at the wrong position.

hi there i have my truggy for some time know but haqve never really tuned it just tried and become confused could you give me the basic understanding to how to tune it thnx. Alex.

OK, if you want to do any tuning you've got to have the engine manual, otherwise you'll risk running it too lean (and hot) and damaging it. Once you've got the instructions its a simple case of slowing turning the carb needles to lean out the engine, a little at a time. Tuning can make a huge difference - your truck will seem like a different beast!

I bought a rc nitro car off ebay, have'nt got a clue what make it is(seller did'nt know either), but it has a force 15 engine in it .I am having trouble tuning it and cannot get it to run tidy. I,ve read many different tecniques on how to tune the little critters but they all say that a good start is to put the carb back to factory settings and go from there.Which i am finding difficult to to get any imformation on. Could you please advise me some way out, as i have owned this rc car for 3 weeks and still yet to get it running tidy/long enough to drive it more than 10 feet.
many thanx,    Paul.

Check out this document, it includes tunning instructions.

I am having trouble with my nitro car.
the car is an alpha chassis with a gx 12 engine.
i can start my engine no problem and it runs very smoothly but when i try to move the car it cuts out strait away. the cogs and wheels will spin smoothly and my throtle is also set up correctly.
i have noticed alot of air in the petrol flow tube and think this is the problen but i am not sure how to stop air bubbles getting in the tube.
how can i stop air bubbles geeting in the feul flow tube ?
could it be the petrol tank ?
any other suggestions ?
thank you. Andrew.

I would replace the fuel line, it's cheap from your local R/C shop, and make sure your fuel tank has no cracks or splits. Set up the engine to factory settings for run-in, then slowly start to tune it. When a car is cutting out straight away, it can be that your idle is too low (the engine should be turning over faster) and that the fuel mix is too lean. Often you'll find that with new engines they need to be run quite rich to start off with, then as you get further into the run-in process you nudge it leaner for better performance. Always remember that you can't damage an engine by running it too rich - you can if it's too lean. Persevere, and it will come good. (Then you've got to tune it again if the weather changes too much....)

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