Can anyone tell me how to figure out how to get to the proper gap for my 2.5 maxx idle screw? I finally got it tuned in good, but want to make sure the idle screw is where it's supposed to be, so I know I haven't compensated a lean/rich lsn setting with it. Traxxas says the gap is usually happy around the 0.7mm to 1.0mm mark, but how the hell do I measure that? Is there a certain # of turns out from a closed position that can get me there?
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Idle screw setting
- Thread starter diavolos
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It should be about the width of a credit card. It should idle at a point where it doesn't stall, but not high enough to make the clutch chatter.
Let it idle for about 5 minutes, or drive it around till it's up to temp, then pinch your fuel line and count the seconds from the time you pinch it till the time the engine quits. It should be between 3 and 4 seconds. Less than that, and it's too lean on the LSN. More than that, and it's a bit rich.
Being too lean on the LSN causes the temp to go way up, and will shorten the life of the engine.
Once the pinch test has been done and the LSN is correct, then finalize the setting on the idle.
I like to speed it up till the clutch chatters, then back it off from there. I prefer my idle to be slightly on the higher side for quicker response for the clutch to engage when hitting throttle, and less chance of stalling.
Let it idle for about 5 minutes, or drive it around till it's up to temp, then pinch your fuel line and count the seconds from the time you pinch it till the time the engine quits. It should be between 3 and 4 seconds. Less than that, and it's too lean on the LSN. More than that, and it's a bit rich.
Being too lean on the LSN causes the temp to go way up, and will shorten the life of the engine.
Once the pinch test has been done and the LSN is correct, then finalize the setting on the idle.
I like to speed it up till the clutch chatters, then back it off from there. I prefer my idle to be slightly on the higher side for quicker response for the clutch to engage when hitting throttle, and less chance of stalling.
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Thanks Rolex, I appreciate it!
Is there a certain amount of turns out from a closed position on the idle screw that will get me to that gap? I'm pretty the lsn is set good, cause it's dying after about 4 sec on the pinch test. I'll also try to set the idle like you suggested.
Is there a certain amount of turns out from a closed position on the idle screw that will get me to that gap? I'm pretty the lsn is set good, cause it's dying after about 4 sec on the pinch test. I'll also try to set the idle like you suggested.
- Messages
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If it's idling now, just a tweeking is all it needs. There's always a specific factory setting, but that's for break in. When the engine is broken in, it will run very poorly with those settings.
Also, check your trim on your remote and make sure the throttle is being pushed against the idle set screw. Otherwise, it won't matter how far you close the needle when the trigger is in it's nuetral position, the only time the idle will drop is when you apply the brakes.
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Good point, Olds. I forgot about that. Set your throttle trim COMPLETELY down, as far as it will go. Otherwise you'll always have a problem at idle, depending on where the trim is set. Make your mechanical adjustment to the idle, and only raise the trim to idle it higher when warming it up. When it's ready to run, lower the trim to zero again.
All good info,
I like to make the final idle adjustments with the radios shut off or the linkage disconnected. Doing this will insure you have a true idle set by the idle screw and not a false idle being controlled by the linkage.
If your radio offers EPA End Point Adjustments, this is the perfect situation to use it. I can tell you how many posts we see that say " When I hit the brakes my engine cuts off". This is caused by a false idle setting due to the linkage. Once you get the true idle set, you can increase it with the throttle trim tab.
I like to keep it a little on the high side as Rolex mentioned. Doing this will make all the difference in the world when it comes to starting and keeping your mill running while its warming up. It will also be more forgiving to the user as they are tuning or learning how to tune their engine.
Good Luck.
-Ed
I like to make the final idle adjustments with the radios shut off or the linkage disconnected. Doing this will insure you have a true idle set by the idle screw and not a false idle being controlled by the linkage.
If your radio offers EPA End Point Adjustments, this is the perfect situation to use it. I can tell you how many posts we see that say " When I hit the brakes my engine cuts off". This is caused by a false idle setting due to the linkage. Once you get the true idle set, you can increase it with the throttle trim tab.
I like to keep it a little on the high side as Rolex mentioned. Doing this will make all the difference in the world when it comes to starting and keeping your mill running while its warming up. It will also be more forgiving to the user as they are tuning or learning how to tune their engine.
Good Luck.
-Ed