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Old 01-10-2011, 12:42 PM   #1
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Unhappy Dynamite .28 Big Red - Only Starts with HIGH IDLE and runs for about 20 secs

Ok so i have the Dynamite Big Red .28 Mach 2 Engine in my Revo, and i have to set the throttle trim ALL THE WAY for it to start and HOLD it or else it will TAKE OFF on me. And then when it starts it runs for about 20 secs and shuts off. It doesn't stay on. I have videos of me ding the break in and it was PERFECT!! now it does not run.

This has me very frustrated as i am about to give up on nitro and go electric but back on topic...

What do i do?

I had troubles with the throttle linkage as when i braked it would turn off but i got that fixed.

I am about to take it to my LHS and let them tune it for me.

But maybe someone knows or give me ideas on WHAT to check, like could it be an air leak or what can it be....thanks.
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Old 01-10-2011, 12:53 PM   #2
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set throttle so there is a 1mm gap, set all other needles to flush, those are factory settings, make sure radio and throttle linkages are all adjusted. so at nuetral there is still a 1mm gap for idle
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Old 01-10-2011, 01:55 PM   #3
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But it still needs for the idle be HIGH for it to start.

i mean when it starts it wants to run away from me..

so i basically am asking what PROBLEMS cause for an engine to need to start with a HIGH iidle? low speed needle, air leak?
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Old 01-10-2011, 01:59 PM   #4
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air leak is deffenelty a possibility. but, a air leak would most likely give your a spuratic idle, and it prolly wouldn't last 20 seconds.

factory set the needles. if necessary, close the gap smaller than 1mm.

if that fails, keep fattening up the needles. its lean, and thats why the idle is high.
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Old 01-10-2011, 05:44 PM   #5
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Richen the bottom needle and the idle should come down if the gap is set correct at 1mm. Keep our air filter off and look at the carb opening to ensure it is staying there when it starts also.
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Old 01-11-2011, 06:53 AM   #6
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OK perfect, thanks a lot for the info.

one more question, i have not changed the glow plug since break in, could it be that the glow plug is bad and therefore needs for the engine to have a higher idle for it to start?

Or maybe it is so LEAN on the bottom end that the IDLE gap needs to be open more than normal for it to start?
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Old 01-11-2011, 08:09 AM   #7
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Quote:
Originally Posted by DjFlipnautikz View Post
OK perfect, thanks a lot for the info.

one more question, i have not changed the glow plug since break in, could it be that the glow plug is bad and therefore needs for the engine to have a higher idle for it to start?

Or maybe it is so LEAN on the bottom end that the IDLE gap needs to be open more than normal for it to start?
Best solution: Buy a new plug from the LHS and get some tuning help there. If they cant help you or want you to pay for the help, then find another shop or track.
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