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engine kills when I hit the brake

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MaxxRunner

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Can any one help me out? I have just replaced the sleeve and piston in my 2.5 and since I did it I can't get a good idle with out turning the transmitter throttle control to max. And when i do that to get it to run and make a few laps and bring it in for a temp check and hit the brake it kills. if i coast it in and adjust the throttle control on the transmitter i can keep it running. seems like when i hit the brake it kills no matter when I do it. Also when it is running strong (but not using the brake) It runs hot (300 plus temp) anything less and it is very sluggish. Did I do something wrong when I did the piston & sleeve? is there a right and wrong side to putting in th piston? If so would it cause this problem? Sorry for the long post but this has me really confused I usually never have a problem getting a engine to run good.

Maxx Runner
 
i would mess with my linkinages and make sure nothing is bent and pulling on stuff. For the running hot and being slow, could it just be lean? beacuse you have to rebreak it in with a new piston and sleve
 
Did you happen to retune the engine after replacing the piston and sleeve? Did you re-break in the engine?

When you do a major overhaul of that nature, you normally need to break in the new piston and sleeve in much the same manner that you broke in the engine when it was new.

Further you will also need to start the tuning over again. New internals means new fuel flow characteristics. I would recommend, resetting the engine to factory presets on the needles and giving the tank a few gentle tanks of fuel. Then retune for performance.
 
First you need to readjust your linkages. Remove the screw from the horn and then remove the horn from the servo. Next turn on the Tx and Rx. Set your EPA's to 0. Reinstall the horn back on the servo. Pay attention to the gap in the carb. You want about a 2mm gap.

From there I would suggest setting your needles back to factory specs and retune your engine. 300 degrees is pretty hot. Of course I've read Traxxas engines tend to run warm. I am not sure if this holds true for the 2.5. 250 to 280 is right about where you want to be.

Good Luck.
 
If your engine runs fine other than dying when you hit the brakes, is it possible you just need to adjust your idle screw?

If you turn in the idle screw far enough that the carb can't close when you hit the brakes, it will stay running. That is of course if you can still get full throttle with your trim all the way back.
 
I did break in the new piston and sleeve , however I didn't think of the linkage set up. As far as the idle screw it makes absolutely no difference where it it set the only way I cn seem to adjust the idle speed is with the tx trim. Will play with the linkage but it may be a couple of days before I can get to it Thanks for the help.

MaxxRunner
 
Well i tried all of the adjustments mentioned above to no avail. I can still get it running but only with about a 1/8 in. gap in the idle stetting, and that is with the tx trim maxxed out. There has been anoter post since I cheked last as far as a air leak problem. i did replace all the fuel line when i did the piston and sleeve , so I don't think that is the problem so where else should I look for air leaks?

Darned Newbies!!!

MaxxRunner
 

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