Nitro car help

[Oreo]

Anyone here have any idea about nitro RC cars ?

I just got one yesterday but am having trouble starting it. It's a HPI Savage X 4.6

I charged the battery fully for the glow starter and battery for the roto-start. So i go to prime the fuel by getting the fuel down the tube just to the carburetor, insert the roto start, put the glow starter on the glow plug and quickly press the button on the roto start. The engine makes the kinda idle noise a nitro car makes, but it doesn't quite start, and as soon as i pull out the rotostart it instantly stops. Theres even a tiny bit of smoke! so the fuel must be igniting.

I have got the fuel mixture nice and rich at factory settings as advised, i have checked the carb and the air filter, aswell as high speed and low speed and idle needles - they all seem perfect to me. But it just wont start.

I've asked on some RC Forums.. but the members arn't what they are here, they take ages to answer and when they do it's a 5word post So here i am.

Thanks.

 

[patonb]

Is the glo plug staying lit?

And have you got the correct one?

 

[Oreo]

Yes the glow plug works fine. But i have figured it out partly, it seems the idle needle was way to low. I turned it a full 720degrees and then finally after 7 hours tinkering it started (admittedly fun though ) But after about 10seconds the engine cuts out. I'm not quite sure why it does this, i leaned it out by about 1/3rd a full turn on the high speed needle and that improved it, but now after a few minutes of driving around slowly it will randomly cut out. I am unsure of whether i need to make it even leaner - i don't want to make it to lean whilst i am still breaking the engine in.

Any ideas on what else could be causing it to cut out ? i have a fuel filter that regulates flow and is definitely working so flow of fuel is definitely not the problem.

 

[Phantom118]

Yes the glow plug works fine. But i have figured it out partly, it seems the idle needle was way to low. I turned it a full 720degrees and then finally after 7 hours tinkering it started (admittedly fun though ) But after about 10seconds the engine cuts out. I'm not quite sure why it does this, i leaned it out by about 1/3rd a full turn on the high speed needle and that improved it, but now after a few minutes of driving around slowly it will randomly cut out. I am unsure of whether i need to make it even leaner - i don't want to make it to lean whilst i am still breaking the engine in.

Any ideas on what else could be causing it to cut out ? i have a fuel filter that regulates flow and is definitely working so flow of fuel is definitely not the problem.

DO NOT lean out your engine. My RC Truck was a Pain to get tuned right but once I got it it was smooth sailing. Does your carb have a low speed needle? it is usually a screw by the throttle arm on the side of the carb.

This is what you mainly need to adjust for smooth runs at low speed.

On the TRX 2.5 for example the low speed needle can be seen in the centre of the throttle arm.

 

[Oreo]

It was a combination of things.

The high speed needle was way way way to rich. I mean, so rich that it wouldn't start properly. We've turned it enough so it now starts and doesn't stall, it is still very rich as there is alot of smoke. The idle speed needle was also way to low. Got a better glow plug which seemed to help, and we're priming it more.

It doesn't start up perfectly, takes 2 or 3 tries with the rotostart and throttle open. But it's getting much better as the engine brakes in.

Yes it does have a low speed needle, that didn't need much adjustment. Anyway after driving it for 2 days and half a gallon of fuel, i crashed into the washing pole in the garden and cracked the fuel tank.

 

[lancec2c30]

Welcome to the world of RC trucks, I am sure you will get to know your hobbyshops replacement parts rack well.

Sounds like you have things figured out already, but if the engine is cutting out after some runtime. It generally means things are too lean to start with. Leaning it out more will only put the engine under more stress.

 

[Poizen22]

oh man i always wanted to get into these things you guys are only convincing me more XD

 

[ricanflow]

Ill stick with real cars.

 

[Oreo]

Welcome to the world of RC trucks, I am sure you will get to know your hobbyshops replacement parts rack well.

Sounds like you have things figured out already, but if the engine is cutting out after some runtime. It generally means things are too lean to start with. Leaning it out more will only put the engine under more stress.

Oh i have already figured this out. I bought a new fuel tank because i smashed my other one, i fit it and replace it then after half a tank with the new fuel tank i break the rear right suspension arm. So yeh, it's an expensive hobby. But in all fairness i am still very impressed with how tough it is, i mean i have had several 40mph crashes with no damage. I have cartwheeled 30meters down a road, no joke. These things roll like crazy somehow.

And rican, I'll race you down a 100meter road

oh man i always wanted to get into these things you guys are only convincing me more XD

Do it, but get a monster truck type or truggy. Don't get crappy on road things. Because truggies are real quick on road and they can cope with off road.

 

[lancec2c30]

Yeah, the power to weight ratio of these things is insane. It's a different kind of enjoyment you will never get from a car.

I am more of an electric person myself, it has really taken off these last couple years too. Traxxas offers all their flagship offroad models that used to be nitro only in brushless configurations, I think they sell better then the nitros too.

My E-maxx

My main truck, the brushless rustler.

I have another rustler that more of a track truck. It's been put on a diet with a dremel.