Zenoah G320RC Ignition Trouble

[Prince Rapopy]

Hello to viewers, I'm new here and this is my second advice-seeking post. Last week, I bought a brand-new Zenoah G320RC engine and got it into my 30 Degree North truck. The problem is that it's not sparking at all, despite attempting it with three different spark plugs. I took it to a hobby shop and they said the magneto system appeared to be defective from the factory. Just my luck, given that my truck's stock engine was defective and I got the Zenoah to replace it.

Anyways, my question now is this: How do I repair this issue? Is it as simple as putting in a new ignition coil assembly, or is there more that will be necessary on top of it? I'm no stranger to wrenching, thanks to the amount of time I've dedicated to learning the inner workings of these engines ever since I got my truck a couple of weeks ago, but I can't do my own fixes if I don't know what needs to be replaced. Any advice would be a huge help!

 

[Rep732]

Have you taken this engine apart yet? Have you removed the coil at any point, what else have you added to the electronics like a killswitch? Check that the kill button on the side of the engine is not stuck down. It sounds as if the air gap is set incorrectly between the coil and the flywheel, the easiest way is to check the gap with a crisp new business card.

 

[spents]

yep, what rep said ,
especially check the push to kill switch as a first point of call, they're not the most reliable design,

 

[Prince Rapopy]

Have you taken this engine apart yet? Have you removed the coil at any point, what else have you added to the electronics like a killswitch? Check that the kill button on the side of the engine is not stuck down. It sounds as if the air gap is set incorrectly between the coil and the flywheel, the easiest way is to check the gap with a crisp new business card.

I did take it apart to add a Dynamite kill switch, but that's all. The kill button moves appropriately. I'll take it apart again tomorrow to check the gap.

 

[Rep732]

Is the red light on when the shop checked that there was spark? Red light on= ready to fire, no light= no spark.. also If the battery runs below its cutoff it will prevent spark as well. If the vehicles on/off switch was off it will not start either unless you unhook the the wire with the red plug.

 

[spents]

I did take it apart to add a Dynamite kill switch, but that's all. The kill button moves appropriately. I'll take it apart again tomorrow to check the gap.

sometimes the switch contacts can get jammed though,the switch appears to be fine because the button will push as normal but the contacts can be closed,
if you disconnect the killswitch temporarily from the coil and see if you get spark, if you do then the switch is jammed closed, if still no spark then the issues somewhere else

 

[smokinwheel]

Unplug the wires on the coil and check for spark , no spark = bad coil or improper coil gap. Reset coil gap and try again. No spark is probably a bad coil.

If you have spark then it is a wiring/electrical issue. Go through and test those components. Ohm meter the switch and start the process of elimination.

EDIT: Sorry spents I just read your reply above. You got it

 

[Dirty30J]

I did take it apart to add a Dynamite kill switch, but that's all. The kill button moves appropriately. I'll take it apart again tomorrow to check the gap.

Remove that stupid kill switch. Leave it unplugged, I’m telling you, pulled on my engine until every knuckle had blisters between my fingers trying to start a 30degree 38cc. It was probably 50% the dynamite kill switch being the problem. The rest was flooding and inexperience.
Return the dynamite kill switch asap before horizon Richards you around on a warranty issue.

 

[spents]

Unplug the wires on the coil and check for spark , no spark = bad coil or improper coil gap. Reset coil gap and try again. No spark is probably a bad coil.

If you have spark then it is a wiring/electrical issue. Go through and test those components. Ohm meter the switch and start the process of elimination.

EDIT: Sorry spents I just read your reply above. You got it

all good fella

 

[Prince Rapopy]

Remove that stupid kill switch. Leave it unplugged, I’m telling you, pulled on my engine until every knuckle had blisters between my fingers trying to start a 30degree 38cc. It was probably 50% the dynamite kill switch being the problem. The rest was flooding and inexperience.
Return the dynamite kill switch asap before horizon Richards you around on a warranty issue.

Update: Looks like inexperience is what was making a fool of me this time! I had the kill switch unplugged, and the lack of power triggered it to keep the engine dead as if the battery onboard had died. After I plugged it in, sparking was going strong. The only trouble I'm having now is that I just don't know how to start engines like these

I've followed just about every guide I can find on starting two-strokes, from closing the choke to opening it, to priming it correctly and even putting a couple drops of fuel through the spark plug hole. So far, none of those tactics have worked regardless of how many pulls I give it. Are brand-new engines just really annoying to start or something?

 

[Rep732]

Yea new engines take a bit to fire because there's no fuel in the crank case. Leave the choke on and pull slowly till you get a pop, is the end of the spark plug wet with fuel yet? Smell it also does it smell like gas? If not keep choke on and keep going.

 

[Dirty30J]

Update: Looks like inexperience is what was making a fool of me this time! I had the kill switch unplugged, and the lack of power triggered it to keep the engine dead as if the battery onboard had died. After I plugged it in, sparking was going strong. The only trouble I'm having now is that I just don't know how to start engines like these

I've followed just about every guide I can find on starting two-strokes, from closing the choke to opening it, to priming it correctly and even putting a couple drops of fuel through the spark plug hole. So far, none of those tactics have worked regardless of how many pulls I give it. Are brand-new engines just really annoying to start or something?

Just the other day I was trying to start my 38cc. It flooded and I never really heard that pop, or it just snuck past me. I realized it was flooded so I held close to wide open throttle on the transmitter and began pulling on it. A splash of fuel came out as it began to sound like it was going to start. A few more pulls with some open throttle and it came to life.
These tiny engines flood with fuel and oil very quickly, and eventually you will recognize what you need to do.
I still recommend going with a better kill switch, the dynamite failed on me. It will just lead you to frustration.

 

[Prince Rapopy]

Yea new engines take a bit to fire because there's no fuel in the crank case. Leave the choke on and pull slowly till you get a pop, is the end of the spark plug wet with fuel yet? Smell it also does it smell like gas? If not keep choke on and keep going.

Thanks for the tip! I have noticed my spark plug coming out a tiny bit damp after a few pulls, and there have been pretty reasonable puffs of misted gas coming from the plug hole if I pull the starter without the plug in.

Just the other day I was trying to start my 38cc. It flooded and I never really heard that pop, or it just snuck past me. I realized it was flooded so I held close to wide open throttle on the transmitter and began pulling on it. A splash of fuel came out as it began to sound like it was going to start. A few more pulls with some open throttle and it came to life.
These tiny engines flood with fuel and oil very quickly, and eventually you will recognize what you need to do.
I still recommend going with a better kill switch, the dynamite failed on me. It will just lead you to frustration.

Yeah, I figured working out the intuition/muscle memory to start these takes a bit of time to develop. Is it better to keep the choke open or closed in case the engine is flooded? I haven't really found much by way of concrete info on that. As for my kill switch, I'll take your advice! Honestly, I just wanted to get one in general for starting out. Going forward, I'll look into swapping it for something better once I've gotten my truck rolling. Are there any kill switches that are community favorites I should look out for?

 

[Rep732]

No problem, so if the plug is damp you need to burn the excess gas/oil off it. Take a micro torch or lighter to the tip and let it burn it off till it's dry. Turn the rig upside down with the plug out and pull on the cord and see if any gas drips out or mist. After that reinstall the plug and give it a go and see if it starts.

 

[cmbscx10]

^^^^ Besides the above

As I am a noob to Gas RC as well the one thing that I can’t wrap my head around is RC Spark Plug Gaps. Spark Plug Gaps can entirely change the way any IC engine runs and is crucial for the “Fuel” portion. Decent spark/too small of a gap and you get a wet plug. From what I have found the suggested starting gap is 0.029 inches. I have a minimum of 2 spares for my 2 Gas RC’s so a total of 6 (2 in RC and 4 Spares). Not one of them was even close to being .029in. I never had one brand new in the box or in the RC from the MFG above .022in. After installing my Kill Switches, gapping the coil and plugs to .029, starting was as the normal chocked, 2-3 pulls to a pop, take f choke and 2 max pulls till a fire.

So, I would suggest a brand new plug and a bigger gap. If your spark is good it may not be good enough to fire off that rich fuel mixture and your washing out the spark with fuel.

Side Note to the experienced: Why are the plug gaps so small from the factory vs the general rule of thumb being .029”

 

[Rep732]

It's a good thought but I never worried about plug gaps on these engines tbh. It's a small engine and the bigger the gap the further the spark has to jump and these coils aren't known to deliver lightning strikes across the plug gap. Now I'm sure there is a sweet spot for the biggest gap before the arc can no longer jump without being blown out or just failing to jump consistently. Smaller gap to me equals reliability in spark and continuous running. Now for me I need my engine to run for a constant 10 minutes then another 20 so to me I'm not going to mess with a hypothesis and i doubt your gaining any performance with increasing plug gap on a 2 stroke. I'd think spark plug heat range would have a bigger impact with combustion than gapping plugs.

Edit: I just read the gap has a bit of control of timing and obviously overall complete burn but it's a small engine so I'm curious now as I'd you'll gain any performance.