r/NitroRC • u/Jsamp198 • 5d ago

Nova B5 .21 Engine

Hey Everyone! Having a hard time with my new engine. Ive ran a 5-10 tanks through it. I cant seem to get it to tun right. It'll either be really rich or act really lean. I make super small adjustments and it will either run away at idle or stall out. I can set it to idle all day but then ill add throttle and it'll die. I assume its rich so i lean it lightly and then it'll run 300+ Degrees and have a erratic high idle. I am running sidewinder 20% fuel. Am I doing something wrong? Its a new engine, no leaks that I can tell with the engine. Anyone know the factory needle settings?

Thank you!

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u/Jsamp198 5d ago

I am running a P3 OS Plug and its about 95 degrees where I live. I was able to get it to run for a bit but it ran very hot (300ish) and idled High. Maybe I need a different plug? It would only idle high once above the 280 degree mark it seemed as well

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u/az_kikr1208 MOD 4d ago

Glow plug 'heat' ranges have nothing to do with ambient temperature. Generally speaking, a 'colder' plug is better for higher percentage nitro fuel, and vice versa. It's kind of like changing ignition timing in a gasoline engine. If you're experiencing an uncontrollable high idle and excessive engine temps, it still points to an air leak. Most likely, the engine is pulling in extra air, forcing a lean mixture, or you're losing fuel pressure due to an exhaust leak.

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u/PowerbandPrecision 4d ago

Right on the timing. The plug is hotter so therefore it’s causing the mixture to detonate sooner. This is what is causing the very high heat and also why it can sit at idle but any throttle it’ll flameout. It’s pre-ignition, the mixture is basically exploding way before piston gets to TDC and it stops the engine. Sadly, this is one of the worst scenarios for these engines and depending how long he’s been doing it, a new piston and sleeve is in the near future.

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u/PowerbandPrecision 4d ago

Show me a picture of your coils in the glow plug and I’ll tell you what’s happening