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Newbie to nitro got a stalling problem

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deano89

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Hi merry xmas to all just opened my first nitro car viper 4wd got it all running okay started wizzing round at 1/2 throttle running in after a lot of reading on correct starting procedure ! but now seem to have a problem it starts fine and runs which i can leave for as short or longer period but as soon as i throttle ,the engine stalls has the screw got to be adjusted or is there something I'm missing
dean
 
HI and welcome!!!

If its brand new its possible that your engine is running rich(your high and low speed needle):)
 
It does sound like you're running rich. BUT, as this is a new engine, it's supposed to for a while. So don't worry about it right now. Keep to your break-in procedure so you don't damage the engine. Soon enough you'll be ready to start to lean out the mix and get some real speed...
 
thanx for the replies trouble is as soon as i touch the accelerator it stalls so can't run it in
even tried just turning the trim up but still stalls so not sure how to get igoing from tick over and still protect the enging
Dean
which way do i turn the screw to lean it off a tad?
 
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Turn it to the right to lean it on most engines. You should only lean it out 1/8 turn at a time, at most.
 
been out had a go trouble starting it today as well when it did run it cut out soon after tried 1/8 turn on screw didnt make any difference the only way i could start and keep it running was by giving it 2 pressess of the primer and once it was running and just about to cut i pressed the primer gently and this kept it going but if left on its own it cut out straight away seems like the fuel is not getting there properly checked the pipes to exhaust that seems fine any ideas?
thanx again dean

it was barnd new xmas day and the exact model is The Redline Racer Nitro Viper buggy if that helps thanx again
 
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Because you had to push the primer to keep it running it sounds like it would be too lean on the low end... Did the manufacturer include info on the stock factory settings? If it did, use those settings as those will usually make the engine run continuously.
 
no just says its factory set and no need for adjustment during run in period the instructions are more like a parts list
 
What kind of engine is it? I know it says that it is set at the factory, but sometimes they mess up and don't set it right. If you can find the proper settings, double check the needles just in case. If you can't, 4 turns out from closed on the HSN and flush with the housing on the LSN are usually good for starting it, then tune from there.
 
i have found a bit on it saying there are 3 adjustments 1/ main adjusting screw 1-1.5mm 2/ idle adjusting screw no settings mentioned 3/ micro adjusting screw again no setting this is the only screw i havent tried!
 
The one you want to adjust is the one on the end of the part that moves. It'll have a little rubber bellows around it. What you want to do is turn it so that it is flush with the surrounding metal. Usually we call it the LSN (low speed needle).

The HSN or high speed needle is the one on top of the shaft that has the fuel nipple on it.

engine_by_Cupooterluvr.webp
 
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The 'main' you refer to is the HSN (high speed needle)
Then there's the idle screw. You know how that works, raises or lowers the idle.
The third one is the LSN or Low Speed Needle. That one adjusts how it idles, and how it punches off the line. It will also effect the overall temp of the engine if set too lean.
The HSN not only determines how it runs at WOT, but also controls the overall fuel flow.
Once you hit the 'magic spot', you'll usually only need to adjust the HSN a little to compensate for changes in ambient temp and humidity.
Make your adjustment on the LSN now, since you've run a few tanks through it. Turn it in (clockwise) only SLIGHTLY and make note of where it was, and if it got better. If you noticed a slight improvement, turn it in a little more.
Keep a constant check on the engine temp, since you are now leaning out the LSN.
Keep posting your results, and we'll keep following up.
 
okay thanx will give that ago first thing tomorrow morning and feed back thanx agian Dean
 
just noticed the picture thanks for that just to get it clear in my head before i start which way do i need to turn it as i am not sure its got to be leaned off as it seems to keep running when i push the primer think is fuel starved
could you please clarify this for me thanks Dean
 
hi on the way to recovery! using the low speed needle adjuster as described , it required a whole turn but now runs and pulls away but when try to accelerate quick it dies how do i know the best setting for this adjustment
and how do i balance the high and low needle settings for the engine to run at all acceleration
thanx again
Dean
 
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By quick do you mean WOT from idle? If that's the case your HSN may be too rich which is causing it to bog and die. You should lean it out 1/8 turn until you can get it to accelerate without dieing.
 
what happens is you can run the car round or hold it your hand and it appears to change gear and cut out probs about 3/4 to full throttle or if you use quick throttle from idle even if you try to increase to full throttle slowly it cuts as well
have adjusted the high needle and idle prior to the one that solved the problem so not quite sure of the correct settings to balance all three!
so probably need to set all three up in correctly in sequence but not sure what i am looking for on each valve tick over one looking through the air filter hole apears to have correct gap of 1 -1.5 mm depending on how trim is set on the hand controller which to start it is on approx 1/4 trim
 
Yah from the sounds of it it is the HSN that is causing your problems. Try setting it flush with the needle housing.
 
hi again
where should the trim on the hand controller be when tuning at the moment it is right at the beginning so once it eventually starts you can increase the revs
what seems to be happening is when you accelerate it goes passed a certain point then just cuts out as though it has reved to its highest point and gone passed it so cuts off
i have read a tunning article here and followed it http://www.nitrorc.com/default2.asp?Introduction=http://www.nitrorc.com/reference/etuning.asp
but i get it running for the minute but once i stop it i can't get it started again and as you pull the cord i can see the fuel go back and forwards in the pipe to the carb ,even does this when primming it doesn't seem to stay at the carb end .
is this just tuning or a dud motor Dean

my engine is a 15cx with 2 speed transmission
 
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