Glow plug stalling

[andthereyouare]

Hi all, I have the savage X ss with the K4.6 nitro engine. Running 25% nitro fuel. Tonight is the first time I actually got it running(I did buy it new a couple of months ago). I now have the dreaded "remove the glow plug igniter and the engine cut off" almost immediatly. I've learned about flooded engines and how to recover and the proper way to prime, finally. All the screws appear to be in the factory position. Am I missing something? I just want it to run. Should I adjust the idle screw?

Thanks. If there are links that I have missed feel free to post them.

 

[francis Labarbara]

Give it a couple of clicks of throttle trim and run a tank threw it and see if you cant take it back out then. Might just be a tight engine. Too rich LSN and too slow idle will both do this. We cant tell what you are dealing with.

 

[Jam Racing 1]

Change the glowplug first off, new engines are notoriously hard on the plug and at breakin the plugs suffer alot of failures....

 

[andthereyouare]

The glow plug is actually fine. I tested it with the igniter and it glows perfectly. I'll get one anyway, though. It's also rough pulling the ripcord I guess cause it's new. Like I said I can get it to start, it just cuts off when I remove the igniter.

 

[Jam Racing 1]

well if the plug looks ok, you can try leaning the high end needle a couple hours and bump up the idle as Francis suggested and see if that helps, but under compression the glow plug is most likely the culprit....

 

[andthereyouare]

Give it a couple of clicks of throttle trim and run a tank threw it and see if you cant take it back out then. Might just be a tight engine. Too rich LSN and too slow idle will both do this. We cant tell what you are dealing with.

Can I really leave the glow igniter on the engine the whole time till the tank is empty? Or am I not understanding.

 

[andthereyouare]

Thanks for the quick responses, I really appreciate it. I tried adjusting the idle and LSN by little bits at a time, still the same issue. I did buy a new glow plug it arrives tomorrow and opted for some "after run oil" too. Read that's a good thing to have. I'm close, I'm really close.

 

[Jam Racing 1]

Can I really leave the glow igniter on the engine the whole time till the tank is empty? Or am I not understanding.

No, if you try to leave it on all the time I am sure it will fall off when driving and possibly damage your igniter.....

 

[francis Labarbara]

Have you removed the air filter and set the slide gap to 1-1.5mm with the idle screw? Do that first.

 

[olds97_lss]

Leave the heater on for a bit until the engine warms up while you blip the throttle with the truck off the ground. Sounds like your just a bit flooded.

I never try to start my rigs at "idle". I see a lot of newer guys do that and if it's tuned perfectly or lean, they will start and run at idle. I run a tad on the rich side, so I give it about 1/4 throttle while pulling the cord and let off as soon as it fires.

 

[Wilson]

Something that I do that I found to help with this problem is turn my throttle trim up a bit on startup, it seems to act like a choke and helps it to stay running. If you don't have a stand just lift it up on the rollcage and gently give it a little throttle after its started to help warm it up a little. After it is running turn the trim back down.

Once you get it running you will be able to tune it so hopefully you can get it to start a little easier next time.

 

[francis Labarbara]

Only fill the tank half full at first. That will lean it out enough probably.

 

[andthereyouare]

All great tips, I tried some suggestions. I have the primer stuff down, good thing. Ran it with a full tank while the glow igniter was attached the whole time. Just to get a tank through the break-in process.

This weekend...
1. I bought and installed a new glow plug (HPI R5-cold)
2. It's about 45 - 55 degrees in my garage so it's kinda cold, I'll try the blow dryer idea to heat it up initially.
3. I have checked the slide gap, it looks to be 1mm open.
4. I do set the throttle to 25% open for the initial pullstart, then back it off to idle.

I have noticed when I did run through the tank fuel comes out of the exhaust pipe, guess that indicates it's on the "Rich" side. Since some of the fuel isn't being ignited.

I'll try the above this weekend and hopefully all will be fine.

Thanks.

 

[olds97_lss]

Plug temp isn't really related to ambient temp. It's related to engine compression and nitro percentage. Higher nitro requires a cooler plug. Higher compression requires a cooler plug. Running 25% nitro, I find that my small blocks like hot plugs and my big blocks like medium. My OS21Tm also ran better with the medium plug.

With these engines, you can't adjust timing mechanically, so you do it by changing head shims and plug temp. The fuel ignites with less compression the more nitro it has. So, higher nitro means you have to mechanically lower the pressure (add shims) and also drop the temp of the plug so it doesn't detonate on you early.

So, unless your running 30% nitro, odds are, you may want a medium temp plug.

All that said, supposedly on a hot day, your engine runs hotter, which affects the heat inside the engine as well, so an engine that runs good with a hot plug may run better on hot days with a cooler plug since the engine is running hotter. The reverse on a colder day.

Regardless, I usually find that the plug I run on a 80F day in an engine with the fuel I always use usually runs ok when it's 30F out as well, so the ambient temp doesn't seem to affect things as much as nitro content and engine compression does.

 

[andthereyouare]

Interesting about the glow plug. I am running 25% nitro.

I did opt for a new glow plug, which is just "R5 cold". It took a couple of pulls and I turned on the electronics to remotely give it some gas. I have now successfully gone through my second tank with the glow plug removed. Only used a quarter of the throttle at the most. Next round is the tuning.

Thanks all for the help getting it here.