sleeper06 Posted January 3, 2009 Report Share Posted January 3, 2009 Run two or three heat cycles(until cylinder feels hot to touch)let it cool completely.Do not lug the motor around .I usually do 5 gear accel in power for no more than 3 seconds then do 5 gear decel under its own power to break in both sides of rings .1 tank break-in let it ripIf its bone stock (new) yamaha sets piston to cyl clearance looseMy brand new she caught a 4 hr break-in diring a snow storm at 9000 rpm the hole time.That bike ran hard for a stock port Quote Link to comment Share on other sites More sharing options...
RollinRhino Posted January 3, 2009 Report Share Posted January 3, 2009 If this is a rebuild I compression test first thing so I have a benchmark number. Then I richen up the jetting a jet or two and let it run for about twenty minutes at about 1/8th to maybe 1/4 throttle. Let it cool down, and run another compression test and see if the numbers are real close. If it is close you can run it hard if you want. Quote Link to comment Share on other sites More sharing options...
HiRoller Posted January 4, 2009 Report Share Posted January 4, 2009 Run it hard. Main thing is keep a load on the engine (don't rev it in neutral) and vary the rpm's. Quote Link to comment Share on other sites More sharing options...
Pincushion Posted January 6, 2009 Report Share Posted January 6, 2009 On my smokers I do the heat cycle method. Using the same gas and ratio as I normally would, I'll start the motor and constantly vary the rpm's for 3-4 minutes until the motor is at operating temp. Let it cool completely and repeat this step once more in the garage. For the 3rd cycle, I start the motor and let it reach operating temp and then go for a 10 minute ride dragging the rear brake or climbing hills to put a load on the motor. I also build my motors dry. I will put a little premix on the rings to assist in getting the jug over them, but that's all. As soon as you kick and it draws in fuel it's seeing lubrication. Just checked the compression today on my 18hr old YZ285 built using this method and it blew 255#. That's a fine compression reading if I do say so myself...... :thumbsup: Quote Link to comment Share on other sites More sharing options...
regalrocket Posted January 6, 2009 Report Share Posted January 6, 2009 Banshees have soft iron sleeves, with harder rings. The cross hatch honing is there to help set the rings. If you don't build up sufficient cylinder pressure, the rings won't be forced against the hatching, and won't set before hatching is buffed off. In other words, JUST RIDE THE THING. I've built sleds, quads, 1,200 drag SBC's and airplane engines. They are all the same. A very short break in followed by actual driving, racing, flying............ Don't make break in a 40 hour deal, or by the time its broke in, it will be due for a rebuild. Quote Link to comment Share on other sites More sharing options...
peterlocal22 Posted January 6, 2009 Report Share Posted January 6, 2009 (edited) ride it soft bro.. you gotta set the rings. no more than 1/2 throttle untill like 1-2hr of riding then go to 3/4 then rip on it bro never run it at a constant speed and shut her down after every 20 minutes for 10 minutes Edited January 6, 2009 by peterlocal22 Quote Link to comment Share on other sites More sharing options...
bonbon Posted January 6, 2009 Report Share Posted January 6, 2009 Couple of heat cycles, ride it easy for about 1/2 tank. Then you ride it like you stole it. I prefer to try and break it. Either it breaks right away or lasts. My last motor made it through some rough ass riding, overheating, sucking in water, and other fun shit. The compression only dropped about 5 psi from fresh after 2 years. Not bad I would say. Only got tore apart now to go bigger. Quote Link to comment Share on other sites More sharing options...
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