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Savage 4.6 won't idle

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T

tophog

RC Newbie
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So I got a 4.6 last Xmas for my son. Had a hellava time breaking it in over the winter and still don't have it idling on it's own. It runs great once it gets warmed up but I can't get it to idle on it's own ...I can set the idle fast but wheels turn when it's on blocks and if I adjust the idle screw down low enough to try and get wheels not to turn it dies.

I have read the manual over and over ...watched the HPI video on their site, etc. Not sure what is wrong at this point. Is the idle suppose to be set via the idle stop screw on the carb where the manual says to set the opening to 1mm ...THEN you use the idle trim on controller to adjust from there ? or do is the idle trim on controller suppose to be set neutral and never used to adjust idle? Think I've confused myself at this point. Oh, we are using the generic Tower Hobby 20% fuel ...is that a problem?
 
did you try richening the hsn up? what do you mean you can't turn the wheel? and is it cutting off during high revs? and lastly, did you leave the fuel in your tank from last christms?
sory for all the questions just trying to help out! :)

I just reread your thing, take the airfilter off, adjust the idle for a one mm gap, then try starting it again and try adjusting the HSN and LSN.
 
I agree with the above post as far as taking your filter off so you can see the opening.
Turn the throttle trim on the radio all the way down, hold the trigger in the maximum brake position, then adjust the idle screw till you get the proper opening.
The one thing you never mentioned was adjusting the LSN. That's the one that controls the idle and initial takeoff. It needs to be leaned from the factory rich settings.
 
I had the same issue with my Savage. The problem for me was the throttle trim and the idle screw. In neutral, the throttle servo was holding the throttle open just slighty. When I applied full brake the throttle closed and cut the engine. Adjust your trim first so that when you apply full brake the carb remains the same. Pull off the rubber air filter so you can see into the carb and adjust the idle screw untill you have 1mm gap when in neutral.

Start it up and see what happens. You may need to return all your LSN and HSN to factory settings, but at least you'll have the carb adjusted properly.
 
Yes, I've had the air filter off a couple times to check the idle gap but have only eyeballed it. How does one ensure it's 1mm ...that's small and a normal feeler gauge won't fit in there as the open is too small/rounded?

It does sound like that's my problem as after leaning out the LSN and HSN the truck runs great otherwise at all speeds. Still smokes some at WOT and doesn't die when I stop the truck however if I put it on a block the tires are turning ...and it's when I adjust the idle speed screw down it dies before the wheels stop turning.

Guess I need to go back to square one and ensure the idle gap is set to 1mm when trim is set to neutral. The trim should be set to neutral before setting the 1mm gap correct and not all the way down (CCW)?

Thanks for all the feedback. I appreciate it.

Oh, the other thing that is most likely due to the idle being adjusted wrong is I have to apply throttle when starting it as it will never start on its own.
 
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set the 1mm gap after you have the throttle set to neutral. If we're correct, once you have the throttle set to neutral and pull off the air filter you'll see little to no gap in the carb. It's at this time that you set the 1mm gap, I did mine just by eye. The wheels may twitch at this point but shouldn't spin. The 1mm gap was just a guess when I did it, I'd be too afraid any guage I stick in there might leave shavings behind. The truck will tell you by spinning its wheels if the gap is too big and stalling when it's too small.
 
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yeah just eye ball it, the opening should look like a skinny finger nail. make sure when you hit the breakes the carb doesn't close!
 
I took off the air cleaner this evening and the gap was at least 1/8". I guess I had screwed in the idle screw a lot trying to get it to idle. I set it back to about 1mm but haven't had a chance to fiddle with it.
 

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