Discussion
Tell me where I'm going wrong and what to do next! I have the needle valve (at default after run in setting) and idle speed settings.
1. I turn on the transmitter and then the car.
2. I then disconnect the tube from the exhaust and blow down it to force fuel from the tank to the engine. I stop blowing as soon as it enters the carb/ engine.
4. Place the glow plug heater in the car and wait roughly 30 seconds for it to heat up.
5. I then insert the jump start and give it a few belts.
6. If it starts but then dies, I increase the idle but 1/4 turn until it can idle by itself.
(When trying to get it to start, I normally blip the throttle. Is this okay practice or should it kick into life by it's own accord?).
7. Engine normally gets started okay.
Now. I had it running yesterday in the warm just fine. I have now come to want to play with it tonight in the colder temp evening.
I could get it to start but then it stalled. I could only get this by giving it some throttle with the controller. As soon as I let off, the car stalled.
So I increased the idle and tried again. After a while the car didn't want to kick in even with some input from the throttle.
I can't start it and have given up and resorted to Mario Kart.
Where am I going wrong? Any useful tips/ advice?
Should I be adjusting the needle valve? I've not long ago grasped the idea behind the other adjuster!
David
1. I turn on the transmitter and then the car.
2. I then disconnect the tube from the exhaust and blow down it to force fuel from the tank to the engine. I stop blowing as soon as it enters the carb/ engine.
4. Place the glow plug heater in the car and wait roughly 30 seconds for it to heat up.
5. I then insert the jump start and give it a few belts.
6. If it starts but then dies, I increase the idle but 1/4 turn until it can idle by itself.
(When trying to get it to start, I normally blip the throttle. Is this okay practice or should it kick into life by it's own accord?).
7. Engine normally gets started okay.
Now. I had it running yesterday in the warm just fine. I have now come to want to play with it tonight in the colder temp evening.
I could get it to start but then it stalled. I could only get this by giving it some throttle with the controller. As soon as I let off, the car stalled.
So I increased the idle and tried again. After a while the car didn't want to kick in even with some input from the throttle.
I can't start it and have given up and resorted to Mario Kart.
Where am I going wrong? Any useful tips/ advice?
Should I be adjusting the needle valve? I've not long ago grasped the idea behind the other adjuster!
David
First off, there is no need to waste 30 seconds heating the glow plug, it will heat instantly.
Setting the mixture can be time consuming and some engines require cold and hot start adjustments, i sometimes have to turn my low speed up half a turn until the engine is warm.
A little throttle is normal when trying to start them, not too much as the engine will spin very high and can cause damage. I normally just up the trim on the transmitter a little until the engine fires up and then back it down.
If it fails to start and idle turn the low speed (the needle directly inline with the carb slide) out (richen) an 1/8th of a turn at a time until it does fire. Once running make slight adjustments to both idle and low speed screws till its consistent, you may need to blip the throttle every so often to clear the new settings through.
Once running drive the car slowly and watch for blue smoke, not too much but enough to know you are just slightly rich. Gradualy increase the revs to make adjustments to the high end mixture (thats normally the screw in the brass barrel on the fuel inlet pipe) until you get to the point where you have a fairly clean throttle response and still observe some smoke. Dont stab the throttle wide open when accelarating as this tends to flood the engine (followed by lots of blue smoke) and can cause the engine to die or bog down.
Experiment with the needles slightly until you get a nice response and a small amount of smoke, too lean and the engine will overheat, first sign of this is a dead plug. Best thing i have found is to put a bit of spit on the cylinder head, if it fizzles away quickly its too hot, it should just about boil on the head before it evaporates.
Just remember enough fuel to smoke a little and you should be ok.
Setting the mixture can be time consuming and some engines require cold and hot start adjustments, i sometimes have to turn my low speed up half a turn until the engine is warm.
A little throttle is normal when trying to start them, not too much as the engine will spin very high and can cause damage. I normally just up the trim on the transmitter a little until the engine fires up and then back it down.
If it fails to start and idle turn the low speed (the needle directly inline with the carb slide) out (richen) an 1/8th of a turn at a time until it does fire. Once running make slight adjustments to both idle and low speed screws till its consistent, you may need to blip the throttle every so often to clear the new settings through.
Once running drive the car slowly and watch for blue smoke, not too much but enough to know you are just slightly rich. Gradualy increase the revs to make adjustments to the high end mixture (thats normally the screw in the brass barrel on the fuel inlet pipe) until you get to the point where you have a fairly clean throttle response and still observe some smoke. Dont stab the throttle wide open when accelarating as this tends to flood the engine (followed by lots of blue smoke) and can cause the engine to die or bog down.
Experiment with the needles slightly until you get a nice response and a small amount of smoke, too lean and the engine will overheat, first sign of this is a dead plug. Best thing i have found is to put a bit of spit on the cylinder head, if it fizzles away quickly its too hot, it should just about boil on the head before it evaporates.
Just remember enough fuel to smoke a little and you should be ok.
Nitro can be very awkward to get right sometimes it takes a few attempts to get it going too.
Setps one and two are fine but if you don't want to blow on the fuel pressure pipe you can put your finger over the exhaust and turn the engine over with the roto start, you'll see the fuel moving towards te carb.
Step three, you don't need to pre heat the glow plug, it heats up immediately.
I'd put all the needles and idle back to the factory settings, these should be able to start the car in any condition.
This is the technique I use for starting nitro's
1. TX & RX on
2. Prime engine with fuel as noted above.
3. Make sure the roto start is inserted to the engine. It usually is after priming.
4. Put the glow starter on the plug.
5. Pulse the glow starter, if the engine doesn't fire after a few seconds I blip the throttle (using full range of movement), I'd do this for max 30 seconds. If the engine doesn't fire then I'd check the glow plug but taking it out and touching it to the glow starter to make sure it still glows. Be careful though as the coils are a bit hot!
6. If the engine does fire keep the glow starter on for another 10-15 secs to help prevent the engine stalling. I usually rev the engine at this time as required.
When I've finished with the car for the day I always run the engine till the tank is empty, this ensures the engine has no oil left in it which will make it harder to start the next time. I have never used after run oil and my engines seem to be fine.
If you are using the car in dramatically different temperatures to the last time it was used then you might have trouble starting it but you'll probably find that you will need to adjust the needles every time you use it.
Setps one and two are fine but if you don't want to blow on the fuel pressure pipe you can put your finger over the exhaust and turn the engine over with the roto start, you'll see the fuel moving towards te carb.
Step three, you don't need to pre heat the glow plug, it heats up immediately.
I'd put all the needles and idle back to the factory settings, these should be able to start the car in any condition.
This is the technique I use for starting nitro's
1. TX & RX on
2. Prime engine with fuel as noted above.
3. Make sure the roto start is inserted to the engine. It usually is after priming.
4. Put the glow starter on the plug.
5. Pulse the glow starter, if the engine doesn't fire after a few seconds I blip the throttle (using full range of movement), I'd do this for max 30 seconds. If the engine doesn't fire then I'd check the glow plug but taking it out and touching it to the glow starter to make sure it still glows. Be careful though as the coils are a bit hot!
6. If the engine does fire keep the glow starter on for another 10-15 secs to help prevent the engine stalling. I usually rev the engine at this time as required.
When I've finished with the car for the day I always run the engine till the tank is empty, this ensures the engine has no oil left in it which will make it harder to start the next time. I have never used after run oil and my engines seem to be fine.
If you are using the car in dramatically different temperatures to the last time it was used then you might have trouble starting it but you'll probably find that you will need to adjust the needles every time you use it.
You may want to check or replace the glowplug.
Running in a nitro engine or running at default needle settings (normal on the rich side) can foul up glowplugs very quickly.
A lot of people normally change the plugs after running in as a matter of course.
Its always handy to have a supply of spare plugs.
Also, remember in cold weather you need to richen the mixture (and use a hotter plug sometimes) and in hot weather lean out the mixture. It's the opposite to what most people think. You wouldn't believe the number of "experienced" nitro people that still dont get that right.
Edit: To be on the safe side do not run the engine until the tank is empty as those last two seconds of the engine running ultra lean can raise the temps too high and mess up the insides. I'm not saying you will destroy your engine (I have done it myself) but nitro engines have a finite lifetime and that will shorten its life after a while.
As for after run oil, I havent really used it much myself (even though its in my pit box lol). Its not so important if you use your engine regularly and keep it in a warm dry environment. But it can make starting the engine difficult if you try to start your engine again only a day or two after using it.
Running in a nitro engine or running at default needle settings (normal on the rich side) can foul up glowplugs very quickly.
A lot of people normally change the plugs after running in as a matter of course.
Its always handy to have a supply of spare plugs.
Also, remember in cold weather you need to richen the mixture (and use a hotter plug sometimes) and in hot weather lean out the mixture. It's the opposite to what most people think. You wouldn't believe the number of "experienced" nitro people that still dont get that right.
Edit: To be on the safe side do not run the engine until the tank is empty as those last two seconds of the engine running ultra lean can raise the temps too high and mess up the insides. I'm not saying you will destroy your engine (I have done it myself) but nitro engines have a finite lifetime and that will shorten its life after a while.
As for after run oil, I havent really used it much myself (even though its in my pit box lol). Its not so important if you use your engine regularly and keep it in a warm dry environment. But it can make starting the engine difficult if you try to start your engine again only a day or two after using it.
Edited by The_Jackal on Sunday 25th May 23:24
Thanks for the replies so far :-)
The glow plugs new and I have a spare in the box.
What are the definitions of the Needle and Idle speed settings. What are there roles, what do they do when adjusted.
The needle is in the default position after run in as I'm not 100% on what that does and when to use it.
The idle fine tunes the engines kick over, the idle. If the engine isn't idling quick enough the engine will start and then die. Increase the idle by 1/4 a turn and try again.
The needle valve....
The glow plugs new and I have a spare in the box.
What are the definitions of the Needle and Idle speed settings. What are there roles, what do they do when adjusted.
The needle is in the default position after run in as I'm not 100% on what that does and when to use it.
The idle fine tunes the engines kick over, the idle. If the engine isn't idling quick enough the engine will start and then die. Increase the idle by 1/4 a turn and try again.
The needle valve....
Default needle settings are normally very rich by default, and for your engine to run at its best normally the high speed needle needs to be leaned out.
Here's a good guide for tuning http://www.maxbashing.com/wb_engine_tune.php
If you really are having problems, try and get down to a local club and get a pro to tune it for you (as opposed to someone who has just bought the expensive gear and thinks they know what they are doing).
Here's a good guide for tuning http://www.maxbashing.com/wb_engine_tune.php
If you really are having problems, try and get down to a local club and get a pro to tune it for you (as opposed to someone who has just bought the expensive gear and thinks they know what they are doing).
Gingerbread Man said:
Mikey G said:
What car/engine is it?
Could you take a picture of the engine/carb to post up here? I may be easier for us to point out which is where for you to adjust.
It's a Hot Bodies Lightning GT.Could you take a picture of the engine/carb to post up here? I may be easier for us to point out which is where for you to adjust.
It has an Idle valve under the carb and the needle valve.
Have a check for a screw on the slide itself, it should be in the middle of it pointing into the direction of the throttle slide. It sounds to me like you are adjusting the high speed needle and idle speed only.
The_Jackal said:
Can you take a pic showing the side of the carb slider?
The low speed needle is usually on the end of the slider.
Do these show what you need to see? If not then I'm not sure where you need a picture of.The low speed needle is usually on the end of the slider.
Is the low speed needle where the servo joins in near the engine?
Edited by Gingerbread Man on Monday 26th May 16:22
Edited by Gingerbread Man on Monday 26th May 16:24
Edited by Gingerbread Man on Monday 26th May 18:58
Gingerbread Man said:
If it sounds bogged down when you crank it. What is that a classic tale tail of?
Flooding or s
tty fuel. i had a similar problem with mine. Completely drain the tank (just pull of the fuel hose to the carb and let it drain), take out the glow plug and invert the car, turn the engine over a few times.Re-connect the fuel pipe, re-fill the tank with fresh fuel and re-insert the glow plug. Attch the glow starer, put your finger over the exhaust pipe and turn the engine over, this will pull the fuel through to carb. Then she should start, all being well that is.
The_Jackal said:
Thats it Mikey.
Being a Hotbodies engine I would be surprised if it didnt have a low speed needle.
If you read the guide I posted though, that should be the last thing you tune.
Different people tune them in different ways, mine has always worked and never get problems. I do normaly tweak the low speed after the high speed anyway, the high speed is only a maximum flow restrictor, its not a needle as such.Being a Hotbodies engine I would be surprised if it didnt have a low speed needle.
If you read the guide I posted though, that should be the last thing you tune.
Last Hot Bodies engine i worked on was my .46 Truckzilla engine in my old Savage, that had 2 adjustment either end of the carb for the low speed (could have been midrange?) and was a pain in the arse to tune, in the end i left the one end stock and just used the one side, once roughly set i started moving the needle across (in one end out the other equally) to see what it does and could find little gain. Hated that truck, too much power and kept snapping driveshafts
funkyboogalooo said:
Gingerbread Man said:
If it sounds bogged down when you crank it. What is that a classic tale tail of?
Flooding or stty fuel. i had a similar problem with mine. Completely drain the tank (just pull of the fuel hose to the carb and let it drain), take out the glow plug and invert the car, turn the engine over a few times.Re-connect the fuel pipe, re-fill the tank with fresh fuel and re-insert the glow plug. Attch the glow starer, put your finger over the exhaust pipe and turn the engine over, this will pull the fuel through to carb. Then she should start, all being well that is.
Is mine too high or am I just trying to find problems.
Takes ages for mine to start up. I'll turn it over and you'll hear it wanting to start. I'll have to keep going for a while or tweak the idle to allow higher revs. Should I be tweaking the needle valve to help it start?
I've read about putting a little bit of oil into the carb directly. Is this okay or a bad way to go about it?
Also, I have a roto start, this seems a pain in the arse to me. Another set of batteries to charge and more to lug about.
Can this be changed to a pull start? Surely this is just a preference thing?
I'll drain down the tank and try again in the next few days, back to work tomorrow.
Edited by Gingerbread Man on Monday 26th May 21:33
Mikey G said:
Your low speed will be on the other side of the carb on the linkage side. Directly inline with the carb slide inside the middle of it will be a brass screw.
Found a picture, I have arrowed the screw.
I'll take a picture of what's round there and you lot can tell me what I'm looking at.Found a picture, I have arrowed the screw.
Edited by Mikey G on Monday 26th May 20:04
Just the manual (seems pretty crap) doesn't mention one and some guides I've read mention not always having one.
I'll be back later with the picture.
Gingerbread Man said:
funkyboogalooo said:
Gingerbread Man said:
If it sounds bogged down when you crank it. What is that a classic tale tail of?
Flooding or stty fuel. i had a similar problem with mine. Completely drain the tank (just pull of the fuel hose to the carb and let it drain), take out the glow plug and invert the car, turn the engine over a few times.Re-connect the fuel pipe, re-fill the tank with fresh fuel and re-insert the glow plug. Attch the glow starer, put your finger over the exhaust pipe and turn the engine over, this will pull the fuel through to carb. Then she should start, all being well that is.
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