Hello New Slayer owner here!
Just got my FIRST nitro truck last week, brand new to the hobby! I have owned many electrics over the years but decided to try nitro this year.
Yesterday I began the break in procedure on my 3.3. I read the manual, watched the DVD, charged the EZ-start and warmed the block with a hair dryer. The Temp outside was high 50's, humitiy 44%. I am using 20% traxxas top fuel by the way.
When the truck started it would not hold idle. Pulling the throttle trigger would stall the motor. I thought the motor was too lean so I raised the low speed needle to bump the idle speed. I restarted the truck and it would now hold idle, ( it spits fuel, and blue smoke like it should). Now when I pull the throttle trigger about half, the truck moves inches, the motor begins to bog then shuts off.
Should I richen the high speed needle 1/2 turn and retry? (because of the 20% nitro?) I really want to break in my motor properly, but I don't want to break it!!
This noob would appreciate any help, thanks!!
You absolutely do not want to mess with the needle settings to get a new mill to run right. They are pre set for break in purposes. The only one you want to mess with is the idle adjustment screw. Return your needles back to factory settings. When the temp outside is cool it will be difficult to break in a new motor and stalling will happen because the needles are set on the rich side for lubrication purposes. I find the easiest time to break in a new motor is in ambient temps of around 70° or higher. Now I will say that I broke my 3.3 in at ambient temps colder than what you have so it's not impossible to break a motor in in cold weather. My amb temps were in the 40's. What you can do is wrap the cooling head with foil to keep the engine temps up. The magic temp you want to be around is 220°F to about 250°F for break in. Adjust the idle higher, this will help with the rich condition the factory needle settings have. This will let more air in to mix with all that fuel and help cut down on the stalling. Also smooth on the throttle and off stabbing it to half or 3/4 throttle will almost ensure a stall. Good luck
Last edited by CarGuy7a; 03-31-2012 at 04:40 PM.
Hummmm Make sure the fuel line isn't kinked or pinched somewhere or the fuel pinch isn't on. I kinked mine when I put my transmission back in on fuel line. It acted like yours half throttle worked great then full throttle it would bog and die.
The high speed needle keep it on the more rich while your are breaking it in. I always have mine on the rich side I'm a basher! Having it rich keeps the engine cooler and engine will last longer in the long run. When it's brand new it comes with he break-in settings on the needles.
It can bog if it is too rich or too lean.
To test the low speed needle I use the pinch test after running when temps are normal and It can hold idle let it sit for a while then pinch the fuel line shut then count 1,2,3 if the engine dies at 3-4ish seconds its good then play with it there.
Low Speed Needle tuning
Last edited by Rock0utRC; 03-31-2012 at 08:57 PM.
you want to do your lsn pinch test directly after a high speed pass so there is no extra fuel in there.
just like you want to check your temps directly after a high speed pass when you have the least amount of lubrication and fuel. if your not to hot on high speed passes then your good for everything below that.
there's no life like a LOW LIFE!
Thanks for all the replies!
I will try and wait for warmer temps before I break in. Or maybe If I can't wait I will wrap the head in foil.
Thanks again for all info!
I didn't break in my Picco 26 Max the guy before me did so he said but I used a hair dryer to heat the engine up before I started it. It wouldn't start right when I got it. I don't know how hot it was but it was warmer and started right up. Oh my clutch was gone too.
Revo 2.5r, Slayer Pro 4x4 Picco .26 max.