Naits14

Hey guys. First sorry if i'm posting in the wrong spot i'm new to the site.

Secondly I need help with my new O.S. motor, it's a 21xz-b and I have been having troubles ever since I purchased it... The motor is near impossible to break in, I am lucky to get it to idle let alone hold a rev at half throttle for break in. I keep messing around with the needles as I have basic knowledge of how to adjust them but I am worried that I will damage something if I keep up what I am doing.

Does anyone else have or has had the same problem, and could give me some tips as to what to do to get it running, as i said I am still in the break in stage... This is my last resort before i take it back to the hobby shop I purchased the engine from and pay even more money for them to get it running..

Thank for the help in advance!

Sideshow Bob

Sound like you arent preheating the engine and the idle is too low.
read this....understand it

http://www.rctech.net/forum/offroad-...eak-bible.html

then go watch this on youtube

https://www.youtube.com/watch?v=oViIFCYKA1s
https://www.youtube.com/watch?v=zy70c4D6mZM

also, if it's true that you have only basic knowledge about tuning/ breakin i think it will be wise to pay the extra to get it run in because an O.S speed is not exactly something you want to use as a test subject for learning the ins and outs of breaking in a racing engine for the first time....might turn out to be an expensive lesson....just saying

BiLL77

iTrader: (4)

I've been running 21 xzb spec 2's for a few years now and never had this problem turn your needles back to factory settings and read Houstons engine break in bible in the nitro offroad forum and you should be fine.

Socket

iTrader: (61)

Pull motor out - ship to RCrenew.com - pay for break in.

Get motor back - put in car - don't worry about break in.

Naits14

Thanks for the help guys! I forgot to say that I have been preheating the engine to about 90-100 degrees C... iv reset the needles and I will give it a read !

My ST-RR EVO

iTrader: (5)

Most of the time when an engine is new and you can't get it to idle it's because the idle is to low and the needles are too rich. Preheat it like you're doing and make sure it's still that temp when you try and start it. The head dissipates heat very fast so it may be worthwhile to heat the engine continuously for several minutes so the heat "soaks". Vary the distance of your heat gun so the temp doesn't get to high. 100°c is fine. Use the throttle trigger to help get it started. Now if it starts and stays on, good. If not, turn your idle up six hours (screw it in). Lean the top and bottom 3 hours. Check your engines temp and try again. If it stays on now, but sounds like the idle is too high or doesn't sound rich, richen the needles an hour at a time and lower your idle. It should be rich at this point. Keep the heat gun pointed at the side of the head to maintain 100°c. If it doesn't stay on and you need to turn the idle up more and lean it out more, go ahead. Get the thing started and running and then you can richen it back up and lower the idle as needed. Don't mess with the mid speed needle (right side of engine on the carb slide). It's not that big a deal. You'll get it. "The best method" for break in its a while other thing. Keep in mind that if the engine doesn't start after a couple of attempts your glow plug could be bad. All coils must light especially the first one.

BiLL77

iTrader: (4)

I always wrap the head with an old wool sock and rubber band when warming up the engine before starting and during break in to keep temps around 200 when heat cycling. The 21 xzb's break in fast, after heat cycling about 3 or 4 tanks i put it on the track and run it hard while tuning.