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-   -   Urgent Help Needed (https://www.rctech.net/forum/nitro-off-road/312686-urgent-help-needed.html)

sperera 07-17-2009 03:24 AM

Urgent Help Needed
 
Hi guys,

Ok so the first tank isnt going so well. I am in the garage now, got it running but it only idles for 10-15 seconds and then stall, its the first tank and running very rich, factory settings rich.

Is this common?

I keep checking the temp to make sure its not getting hot, so I put a drop of water on the heat sinks and it doesnt sizzle, boil or even steam. So I dont think im getting it too hot.

When I try to give it a small rev it stalls out, sometimes it revs up but very unresponsive.

Help me please I really dont want to cook the engine or damage it in the break in process.

NitroDirtMan 07-17-2009 03:31 AM

very common for a new engine. try leaving your glow ignitor on it for a while., dont just take it off the moment the engine starts. you could try leaning out the HS needle just a touch.

sperera 07-17-2009 03:36 AM

Leaving the ignitor on certainly helps. I will persist with it, could it be anything to do with the idle screw which I havent touched yet?

DOMIT 07-17-2009 03:49 AM


Originally Posted by sperera (Post 6078845)
Leaving the ignitor on certainly helps. I will persist with it, could it be anything to do with the idle screw which I havent touched yet?

You could idle it up a touch... normally we DON'T idle it up during break in, at least not with the idle screw... because idle will change as it breaks in.

Use your radio trim to hold the idle up a bit... that way as the motor breaks in and the idle comes up you can bring it back down.

And the HS (High Speed) needle doesn't really do much for the bottom end (mixture at idle.) You use the LS needle for that. ;)

Wrap some foil or a washcloth around the head to get the temps to come up... you want it up around 220-230 while breaking in.

A heat gun is recommended for starting, to pre-heat the engine... and a temp gun to be sure you are in a safe range. (under 200 is hard on the engine... over 230-240 is also hard on it for a different reason.)

(Note that I'm giving you temps in degrees farenheit...) (sp?) Ummm... you want temps to be at least 100c but not too much more than that.

sperera 07-17-2009 05:38 AM

Thanks mate i just finished running half a tank, its past 10pm here and I dont want to push my luck with the neighbours considering I was idling it in the garage.

I adjusted the trim on the controller and that seemed to help a bit, it now idles for 2-3 mins and then stalls, probably because its running so rich.

I dont have a heat gun yet. I will have a look for one over the weekend. I know for sure its not running over 100 degrees celcius because I keep putting a drop of water on it and it does nothing, doesnt steam, doesnt bubble, just sits there but to touch it feels quite warm, can only leave my hand on it for 5-10 seconds before it hurts.

I will fill up the tank tommorow morining and run it around the street at a low speed, that should give it some air flow. 5 tanks later and I should be able to dial it in and increase the speed. Im going to stay on the safe side for now, dont really want to have to repalce the engine any time soon.

RMKinWI 07-17-2009 05:46 AM

Lean the HSN an hour at a time until it runs and than continue the break in process. You likely have fuel coming out of the pipe like crazy - meaning its to rich.

sperera 07-17-2009 05:54 AM

There is fuel coming out of the pipe but not large amounts, I got it sitting on a cardboard box and that has some stains on it from the stuff coming out of the pipe.

I know im running it very rich but I really dont want to do any damage to the motor, not this early on anyway.

I will give you all an update tommorow nigh when I have hopefully run a couple more tanks in it. Im going to get it out in the street instead of sitting it on a stand like I was doing today.

scwrod 07-17-2009 07:25 AM

Just FYI. It is also not good if the motor temps are too low. Breaking in is about the only time I use my temp gun. I highly recommend a heat gun for this process. I do also wrap the head. I use foil myself.

DOMIT 07-17-2009 07:50 AM


Originally Posted by RMKinWI (Post 6079080)
Lean the HSN an hour at a time until it runs and than continue the break in process. You likely have fuel coming out of the pipe like crazy - meaning its to rich.

WHY do y'all keep saying to lean the HSN? Lean the LSN to lean it out at idle and raise temps. Just a tiny bit, maybe "1 hour" if you consider the needle to be a clock face, or 1/12 of a turn.

idle = low speed

coviello 07-17-2009 08:13 AM


Originally Posted by DOMIT (Post 6079385)
WHY do y'all keep saying to lean the HSN? Lean the LSN to lean it out at idle and raise temps. Just a tiny bit, maybe "1 hour" if you consider the needle to be a clock face, or 1/12 of a turn.

idle = low speed

yes. but during break in if you lean out the low speed. thats going to make your idle go up. try going lean on the high speed. 1 more hour. just to get it up to temp. you really want to be about 215-220 during break in.

sperera 07-18-2009 09:09 PM

I think its time I bought a heat gun, im only going on feel at the moment and thats not accurate in the slightest, im sure im not getting it hot enough but i dont want to cook the motor like I did my last one.

Ill drop into the hobby shop next weekend and price up a heat gun.

crotty777 07-18-2009 10:00 PM


Originally Posted by coviello (Post 6079468)
yes. but during break in if you lean out the low speed. thats going to make your idle go up. try going lean on the high speed. 1 more hour. just to get it up to temp. you really want to be about 215-220 during break in.

DOMIT is right he needs to lean the LSN to bring the temps up at IDLE. you can adjust the high speed all day and it hardly going to change the temp at IDLE unless u lean it out a lot i guess

losi_racer 07-19-2009 12:00 AM


Originally Posted by coviello (Post 6079468)
yes. but during break in if you lean out the low speed. thats going to make your idle go up. try going lean on the high speed. 1 more hour. just to get it up to temp. you really want to be about 215-220 during break in.

thats why you lower the idle :nod:

omarwashington 07-19-2009 12:09 AM


Originally Posted by sperera (Post 6079052)
...

I adjusted the trim on the controller and that seemed to help a bit, it now idles for 2-3 mins and then stalls, probably because its running so rich.
...

+2 on leaning the lowspeed, Temps are too low when you do the spit test on the heat sink.

oggietiu 07-19-2009 03:57 AM

I usually do both the lsn and hsn little by little during breakin. Lsn to help it idle and get to temp while on the box fir my first tank. Second tank i run it on the ground doing figure 8s. This is the time i touch the hsn little by little till i feel the engine can handle another increase in rpm then i touxh hsn again while checking temp from time to time keeping it above 200 f every tank i shut it off and let it rest for 10 minutes then adjust the hsn again


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