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Need Help to Identify and trouble shot a problem

Need Help to Identify and trouble shot a problem

Old 10-18-2009, 07:40 PM
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Questions?? Need Help to Identify and trouble shot a problem

Having some trouble with the needels hear I belive A=High B= Idle C= ???? D= Low end. I started my motor and it was constant high idle as if i had the throttle completly open. When I would hit the brakes it would shut off. I belive to have fixed the problem I sealed the carb up around the base and also the neck where the air filter goes. I just wanted to double check and make sure I wasnt lossing my mind on what was going on.
On part C of the pic I have been told two diffrent things one is that it is mid range and recommended not to mess with unless an expert tunner and the second was a throttle stop.

Thanks for any and all reply
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Old 10-18-2009, 09:07 PM
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your correct on all the needle's....but i have no clue what "C" is.....that's an old Axe rossi motor ?
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Old 10-18-2009, 10:06 PM
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"C" is a throttle stop for the carb, and there's no need to mess with it unless you need to remove the slide valve.

If the engine is shutting off when you hit the brakes, one of two things is happening: 1; the idle speed adjustment isn't set properly to keep the carb open a minimum amount, or the 2; the fuel mixture adjustment on your low-speed needle is so out of whack that engine can't stay running. Start by adjusting "B" in the clockwise direction until the slide valve is open a minimum of 1mm. the carb should never be able to shut all the way - hopefully this solves the problem. Even if it does, you may need to adjust the fuel mixture settings to keep the engine running reliably. Try adjusting the idle speed screw and let me know what happens.
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Old 10-18-2009, 10:43 PM
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Sounds like a linkage/trim problem. Make sure the carb is closed with the radio at idle. Never use the throtle trim on the radio to set idle speed. Then use the idle screw to set your idle speed.
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Old 10-18-2009, 10:49 PM
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how come u cant use the throttle trim to come down the idle a bit i do it it seems to run fine
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Old 10-18-2009, 11:03 PM
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I don't think so baught it from AMainhobbies about 2 weeks ago
Originally Posted by Integra
your correct on all the needle's....but i have no clue what "C" is.....that's an old Axe rossi motor ?
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Old 10-19-2009, 12:35 AM
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Originally Posted by tc5 man
how come u cant use the throttle trim to come down the idle a bit i do it it seems to run fine
Because when you hit the brakes, where ever the throttle stop is set on the carburettor is where the engine idle is going to sit at. By using the throttle trim on your radio, all your doing is advancing the servo so that at 'idle' you're actually applying a small amount of throttle.

Next time your buggy is warmed up, bring in it in and let it idle. Then hit the brakes and notice your idle speed will drop because its then being allowed to hit the carby throttle stop.
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Old 10-19-2009, 09:58 AM
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oh ok yea the idle did barely dropped off when i hit the brake i proberly could just click the trim foward a little and it will proberty be fine, it runs good though and the idle isnt to high
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Old 10-19-2009, 01:34 PM
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setting the idle with radio trim is WRONG...no matter what way you look at it.
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Old 10-23-2009, 09:50 AM
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This is the low down on what happend today when I made my few adjustments to the carb I had to bring the idle screw up more then the recomended 1mm and had to richen up the low end screw ran temps up to 250 F and didnt want to push any further so I shut it down. Would run fine wit a lil bit of a steady exaughst smoke. So anys suggestons to how to keep a stable temp now also the plug was very wet and the wire was shiny. Also running a cold plug The outside temp was in the mid 50's and the air was very damp rain today so I done all my work in a shed/
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Old 10-23-2009, 10:03 AM
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i would use a meduim heat plug that should keep the temp constant thats what i use and my nova runs great
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Old 10-23-2009, 10:56 AM
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That was one of my thoughts on that note my plug was reading red at times and green also with my ignitor could that be signs of plug going bad even though plug is not distorted and fairly new.
Originally Posted by tc5 man
i would use a meduim heat plug that should keep the temp constant thats what i use and my nova runs great
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Old 10-23-2009, 11:03 AM
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I might be wrong but it really sounds like you are super lean on the low end, not sure about high end because you havent told us how it is once you get rolling. Its straining for fuel hence the high idle. You might want to see if you can find the factory needle settings and start over. That has worked for me in the past when someone decided they should start cranking the screws on my mill and I had no idea what they did.which I have learned I will never allow to happen again. BTW...250 isnt bad depending on what engine you have which we still dont know. Tune to performance....good smoke and response and you should be fine. Engine temps vary considerably depending on what kind. Reedy's only run solid around 260-270 which would freak temp tuners out but others are around 220...my Dynamite is right at the 220 mark and thats not a "race" tune. If it feels right and blows smoke then run it.
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Old 10-23-2009, 11:06 AM
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What fuel are you using? Axe motors are not shimmed for 30% from the factory. I learned that the hard way. If you are running 30% you must add .02mm of shimming. Your low end seems to be way to far out aswell. That is a mamba x1 evolution right?
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Old 10-23-2009, 11:13 AM
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This is what the factory settings is suppose to be: " The factory initial setting is the following: Main needle 3.5 turn open from closed position- Idle needle 2.5 turn from closet position. " There is no misspelling on my part this is exactly coming from the instructions that they have sent me with my motor. Now are they calling the idle needle the low end or the acctual idle needle the high I can fig out its just the last part in the quote that I have given.
Originally Posted by midwestcajun
I might be wrong but it really sounds like you are super lean on the low end, not sure about high end because you havent told us how it is once you get rolling. Its straining for fuel hence the high idle. You might want to see if you can find the factory needle settings and start over. That has worked for me in the past when someone decided they should start cranking the screws on my mill and I had no idea what they did.which I have learned I will never allow to happen again.
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