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How do I get the engine to run right?

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How do I get the engine to run right?

Old 05-02-2022, 07:27 PM
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Default How do I get the engine to run right?

My nitro engine car has been a complete pain in the *** since I got it the other day.
On the first day it took hours to get it to even start and idle. It wasn't starting until someone told me to physically move the throttle servo so the carb is 1/4 full. Eventually over the course of a few hours this person told me how to adjust the HSP until it was idling for extended periods. Although the idle was very high and it would often be enough to drive the wheels forward. Throttle trim was fully open and closing it would stop the engine or make it impossible to start.

Today I decided to try and tune for a lower idle after seeing some videos that said your idle gap should only be able the width of the wire used to make a paperclip. So I adjusted my idle gap to this. And then I tried following this flowchart: (Which apparently I'm not allowed to post)

At first my engine wasn't even idling without the glowplug igniter. Let alone for one minute. And was an absolute **** to start.
I started to lean out the LSP. It's still not idling well but I can keep the car idling if I rev it within a few seconds of removing the igniter. And then after that it seems to be ok. Throttle trim is still fully open. It wont start without it. Thing is making the LSP more lean doesn't seem to make it idle better or easier to start it seems to just stay the same.

I then drive the car around at half throttle and low revs it's fine. But the second I start to rev up or apply higher throttle the motor dies.
I tried following this flowchart but it says that dying under throttle can be caused by both too rich and too lean!

I've tried going leaner on the HSP and it doesn't get better. So I go richer, still not better, leaner, no, richer no. I'm just twisting the screw back and forth and nothing seems to work to stop the engine from having no power and dying.

It's always a complete **** to start too. All the skin from my fingers has been pulled off by the pull start handle and I've actually injured my muscle from the having to rapidly and repeatedly pull the chord like a man possessed to even get it to fire. I got a little smoke coming from the carb hole too. Don't know if that's normal.

My manual has no default settings apart from the HSP which is "Two and a half turns from fully closed" for engine break in. I set it to this and I get an engine thats hard to start and dies under throttle. I lean it out and I get the same. I richen it and the same. So am I too rich or too lean?

Can someone just give me some default needle settings that I can use as a baseline where the car will start well, idle and I can tune for high end? 18cxp engine.

Last edited by Chinamantis; 05-02-2022 at 07:40 PM.
Old 05-04-2022, 07:40 AM
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Your problem is hard to resolve on line. First it sounds like both needles are off. The low sounds rich to me. Go in a 1/8 turn at a time until it will idle and rev up. Then work on the high. But honestly the best thing you can do is find someone close to you that can help. Have them show you how to do the pinch test for high end. When I set the low end on a plane engine I use the glow igniter. Let it idle for 10 seconds with out the igniter. Put the igniter on for a few seconds. If the engine picks up speed it's rich.
Good luck, david
Old 05-07-2022, 02:23 AM
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Those factory settings are general settings to get the engine to start. The problem is in most parts of the world, they’re WAY too rich. I lean the high speed 1/4-1/2 turn before ever adding fuel. Start the engine after preheating it (preheating makes life a LOT easier) and get the idle set so it will idle on its own. This usually must be leaned 1/4 turn or more. This only after setting the idle gap - .5mm for well broken in engines and in some cases .6-.8mm for new engines. As the e fine breaks in, the idle will creep higher. Drop the idle gap little by little until you get a stable idle.

Don’t baby it. Get it started, get it hot, and let it rev.

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