Dynamite Killswitch & FlySky GT3B

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Well, I was about to order the easy starter while I was watching EzeeTrade Racing on YouTube. He happened to be taking an engine apart after it wouldn’t start & he showed damage to the top of the piston. I decided to take a look at the top of my piston just to see if as it’s sat next to me, and it doesn’t look good!

Pretty sure the piston & therefore engine is done for. 😢

There is a triangle hole off-centre on the top of the piston pointing towards the exhaust (which having googled it seems to be in pics of brand new pistons - though mine isn’t a perfect triangle now) but then around it are 3 pretty bad indents/gouges from whatever shrapnel has been thrown around in the engine & smashed into it.

Am I safe in assuming this engine is done for and it’s the reason it won’t start? If so, I’ll be asking RCModelz for a replacement engine. All I’ve done is follow their break-in procedure. The changes I’ve done have been done meticulously & whenever I’ve taken the plug out, it’s been indoors and with extreme care to ensure not even a spec of dust went in the engine, so I know it’s not from something I’ve done!
 

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Worst case if it is down on compression is probs a piston ring .
Get the mixture leaner and it will soon blow all the crappy unburned oil out.
Even a full top end , piston,cylinder and ring is going to be well under £75.
I would not worry though , these things run like crap when the mixture is wrong.
 
Even if the engine has grenaded for some reason , changing to an easystart is a good move , the pullstarters are a known weak spot.
They should replace such a low hours engine if it has gone bang , changing the starter should not affect the engine , likewise the kill switch.
 
Thanks mate, much appreciate your support 🙏🏼

I will give them a call in the morning. Will be easier to explain what’s happened than in an email. I hope they can replace it, or even worst case give me the equivalent money off another engine.

I’ll definitely get the easy pull start regardless the outcome. If they do replace the engine, I may even be cheeky and see if they’d fit it for me. I just want to wait and see what they’re prepared to do before spending more money - I’ve been ordering stuff from them every other day the past month 😂
 
If they do offer money off another engine I would try the 36 or 38 in the truck , should have more grunt right away.
I was thinking it would be nice to upgrade to the 38 if given the chance as then it’s like getting one for half the price 😅

I tried to call them earlier but sadly it’s just an automated line. They only offer email support, which to their credit they responded to within 2hrs. Currently they’ve said I’ll have to send the engine to them for further inspection, along with asking a few questions about what fuel, oil mix & carb settings I used. Now waiting to hear back from them after answering their questions. Hoping they get back to me before they close today as would like to get it packaged up so they might be able to look at it on Friday & make a decision.

I’m going to guess that they’ll try & fix it unless it’s not cost effective for them. If they fix it, I’ll probably sell the engine & get the 38 or a Zenoah anyway, as my faith in the durability of this engine has taken a rather large hit! 😕
 
So I’ve not heard anything back yet & I’m thinking I may just go ahead and order the 30DN 38cc Engine w/ an Easy Starter anyway, as I think returning this engine is going to be a long af process & I’m impatient as hell.

How much of a drop in job is it? Am I going to have to swap a lot of stuff over from the 29cc engine? Wondering if it comes with a suitable clutch & if my stock exhaust will bolt straight on? Also wondering if the carb comes attached/assembled & is the ignition coil a dual spade or uses a ring crimp on one side like the 29cc, as I’ll need another kill switch if so as the wires are too short to cut again & change now 😆

Having said all this, I’ve seen some people have had quite a few issues with the 30DN 38cc though. Is it worth the extra HP or should I just drop a 29cc Zenoah in for reliability?
 

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So I’ve not heard anything back yet & I’m thinking I may just go ahead and order the 30DN 38cc Engine w/ an Easy Starter anyway, as I think returning this engine is going to be a long af process & I’m impatient as hell.

How much of a drop in job is it? Am I going to have to swap a lot of stuff over from the 29cc engine? Wondering if it comes with a suitable clutch & if my stock exhaust will bolt straight on? Also wondering if the carb comes attached/assembled & is the ignition coil a dual spade or uses a ring crimp on one side like the 29cc, as I’ll need another kill switch if so as the wires are too short to cut again & change now 😆

Having said all this, I’ve seen some people have had quite a few issues with the 30DN 38cc though. Is it worth the extra HP or should I just drop a 29cc Zenoah in for reliability?
I’ll respond with what I know. I have a 38 and it runs just fine now that I’ve worked out the tuning learning curve due to inexperience.
I had many troubles, from it running too rich and flooding, my dynamite kill switch intermittently not working preventing start-up, and some leaky gaskets.
I will vouch for the 38cc but I’m positive a 32cc zenoah will be a solid engine for this truck. The 38cc sounds like a dying goose off the line while the zenoahs seem to rev up rather smoothly.
I’m too late, I read your other posts and it looks like you grabbed a 38.
 
Haha yeah I went with the 38! I did see your build thread and the troubles you had beforehand - though according to their website they did make some changes to the 38 since its initial release, so hopefully they’ve worked out some of those issues 🤞🏼.

I decided against the Zenoah just because it didn’t sound quite as simple to ‘drop in’ and the additional parts needed to make it work would’ve added up too much for me to justify it. RCModelz advised me I could easily swap parts over to the 38cc and just bolt it in & setup the carb - which now comes already fitted.

I guess time will tell at this point!

One thing I wanted to ask you was, did the ignition coil have two spade fittings so the Dynamite K/S just fitted on as is? I hate the ring clamp on the 29cc with a passion. 😂 It makes the Stop button get pushed out the case/cover. I ordered another one just in case so I don’t have to try and re-fit spades on the K/S wire.
 
Haha yeah I went with the 38! I did see your build thread and the troubles you had beforehand - though according to their website they did make some changes to the 38 since its initial release, so hopefully they’ve worked out some of those issues 🤞🏼.

I decided against the Zenoah just because it didn’t sound quite as simple to ‘drop in’ and the additional parts needed to make it work would’ve added up too much for me to justify it. RCModelz advised me I could easily swap parts over to the 38cc and just bolt it in & setup the carb - which now comes already fitted.

I guess time will tell at this point!

One thing I wanted to ask you was, did the ignition coil have two spade fittings so the Dynamite K/S just fitted on as is? I hate the ring clamp on the 29cc with a passion. 😂 It makes the Stop button get pushed out the case/cover. I ordered another one just in case so I don’t have to try and re-fit spades on the K/S wire.
You will be doing the same wiring process. I had to crimp on a ring terminal
 
You will be doing the same wiring process. I had to crimp on a ring terminal
Damn it 😂 Ah well, at least I know which way to fit them this time so the cable won’t end up awkwardly short and mess up the Stop button mounting nicely.

Oddly RCModelz lists that style of ignition coil being for their engines & 23cc to 30.5cc engines. Seems odd they’ve stuck it on their 38cc if it’s only rated to 30.5cc on others.
 
Damn it 😂 Ah well, at least I know which way to fit them this time so the cable won’t end up awkwardly short and mess up the Stop button mounting nicely.

Oddly RCModelz lists that style of ignition coil being for their engines & 23cc to 30.5cc engines. Seems odd they’ve stuck it on their 38cc if it’s only rated to 30.5cc on others.
The coil should be fine. They are probably all the same really
 
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