break-in or break it

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redcat racer 89

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im about to get my new engine for my xb either today or tomorrow,how should i break it in,its a cy29cc from ddm with a stuffed crank rated @ 4hp.


i want my engine to have a long and happy trouble free life


iv heard a few was to break it in


1.drive it like i stole it or grip it and rip it


2.idle half a tank,then go for it


i never break-in my weedeaters or chainsaws,they have never givin me any problems


HELP
 
Weedeaters and chainsaws are broken in usually by the factory, and are a lot less HP than these.

I'm also new to 1/5, my frist a few months ago. I let it idle a little rich for almost an entire tank. First half of second tank i would blip the throttle every minute or so, then second half ran it up and down the street almost WOT. Seems to run great. Not sure if this was proper, you'll want advise from a pro.
 
I just rebuilt my 26cc, and this time around all I did was let it idle until it initially got up to running temp then gunned it after that. I always shut them off after about twenty minutes and let them cool. This was a recommended method I got from the HPI baja forums. I don't think you want to leave it idling for an extended period of time while seating in the ring.
 
The bore > plate > ream cylinder plating method used by Zenoah and CY leaves the cylinder out of round with differences in diameter at various levels of the cylinder. You will notice the uneven wear pattern on the cylinder wall after 1/2 tank. Idling an entire tank won't hurt your engine. Most likely you will foul a plug if the engine is rich. Typically, my method (700cc tank) is to idle 1/2 tank and blip the throttle a few times every few minutes to clear out any built up oil. The last half tank I will run the vehicle and start tuning my high speed needle. Be sure not to WOT for more than a few seconds.

Since the XT/XB have much smaller tanks than a 5B, MT, or TT. Try idling 3/4 tank and then fill it back up. You don't want to run out of gas because the engine runs extremely lean a few seconds before it runs outta fuel. Run the 3/4 of the second tank as described above. Then, let er rip.
 
Deluge said:
I do a warm up lap, then beat it. You need to put a load on the ring so it'll seat and seal properly. Start it, warm it up and let it rip.
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Same here first 3 minutes at 0 - half throttle runs then next 5 min 0- 3/4 t and then full power .Usually i`m getting 12 galons + on each headkit. Make sure to vary the rpm during break in , don`t keep it at the same rpm level.

This way you will achieve great engine response and decent live. :)
 
Wow. A bunch of different methods. Which do you choose? I was told by a local company that builds, ports and polishes, and races these motors professionally, that the best way is to just drive it but not to hammer on it. Drive it moderately over different terrains and do this for a full tank. Yes, don't let it run out of fuel. That's bad at any time. I was also told to run a regular 2 stroke oil during break in and then switch to synthetic. This will speed up the break in process and then the synthetic will prolong the engine life. Something tells me that these engines are a bit more forgiving than say a nitro engine.
 
If you pulled and engine head at 1/2 tank, 1 tank, and 1 1/2 tanks you will see why you don't wanna WOT for too long before at least 1 tank. The imperfections in the plating at 1/2 to 1 tank are very noticable. I don't like to think about the friction generated with a piston ring going up and down those sidewalls at 17k+ RPM for too long. The very first thing to heat up is the steel ring. The heat disperses to the piston. The problem with that is the very small lip above the ring will expand and then catch the exhaust, intake, or xfer ports. Most of the time it'll be on the exhaust side.
 
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