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High RPM at start up

Old 03-17-2010, 10:49 PM
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FunkDoc201
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Default High RPM at start up

I'm fairly new to the Nitro scene, coming from electric. I've gone through the break in period of my nitro star 3.0 and have ran another 3 tanks on a tuned engine. I properly stored it for the winter and now getting it ready for spring and summer runs.

I have a few questions and I hope someone can help me out.

1. with a fully charged igniter and good glow plug and carb primed, I pull-and-pull on the pull start till I start to feel like popeye's arms, then the car starts. Sometimes i have to de-flood the engine.
Question: What is causing this engine to not turn over and why is the pull start tight at TDC?

2. again with the same scenario as above, but now that the car is running...the engine is running at a very HIGH RPM. I've checked my needles and have zero them out to flush and factory settings. I've also check my throttle trim. I've put the car down on the ground and if i were to let go, obviously the clutch has engaged due to the high rpm, it will take off on me. So i have to cut off the fuel supply to kill the engine.
Question: What is causing such a HIGH RPM once i get the engine started?

I hope someone can help me out here. I'm all out of ideas.
Old 03-18-2010, 01:12 AM
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D.DJ
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Default RE: High RPM at start up

Answer for No. 1:
The tightness at TDC is normal for a new engine even after break-in. After a few tanks it will eventually loosen up. As for de-flooding the engine, you shouldn't have to do it all the time, only prime the engine until the fuel reaches the nipple on the carb, then pull a few times to get it running.

2:
You either have the low speed needle set too lean or the idle stop screw is screwed in too far, causing it to open up too much. This is all assuming that there are no leaks in the carb and engine. If you do have leaks, I would seal them up ASAP or you get problems in the future and will always be "chasing a good tune"

Good luck on solving the problems!
Old 03-18-2010, 06:19 PM
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GYNAIKAS
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Default RE: High RPM at start up

DDJ -> +1
Keep in mind that "carb-opening" setting needle doesnt have factory setting. Depends on weather conditions (temperature/pressure) and it's slightly different in every engine, so find your own setting. Check for fuel line leaks just to be sure. Low speed needle also adjust idle in a way. High speed needle doesn't affect it as much.
Old 03-18-2010, 06:32 PM
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wrcsti
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Default RE: High RPM at start up

Check the trim on your throtle. Also does your engine shut off after pulling the igniter off?
Old 03-19-2010, 09:29 AM
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D.DJ
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Default RE: High RPM at start up

GYNAIKAS: exactly right, but usually all factory setting are right in the ball park of where you should be at. A few adjustments is all it takes to get the perfect tune.
As for leaks, my GOD they are annoying!! You don't want any leaks in the tank, the lines or the carb or they will destroy your patience! Just make sure its all the way it should be and go for it!
Old 03-23-2010, 06:49 PM
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FunkDoc201
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Default RE: High RPM at start up

Thanks everyone for the help. After popping off the air line, it revealed that the carb was wide open causing the issue described at start up. I've made the necessary adjustments and got my engine back in tune.

Thanks again peeps! This is a great forum and it gets results!
Old 03-24-2010, 07:05 AM
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Default RE: High RPM at start up

I'm glad you found what the problem was! Happy bashing!

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