speny46 Posted March 1, 2006 Report Posted March 1, 2006 just rebuilt the top end of my shee (piston, rings rebore etc) how long does it have to be broken in for and with what mixture please help Quote
Team20 Posted March 3, 2006 Report Posted March 3, 2006 Mix 40:1 (twice) with 91 and ride till you empty one gas tank on flat. Or you can do half and half of 91 and C12 but it has to be jetted at 340 or 350 and again empty one gas tank on flat. Then gradually break it in by doing 3 gallons of C12 and 2 gallons 91. Then to 4 gall of C12 to 1 gall of 91 to the end of full C12 racing fuel. Quote
BigRed350x Posted March 3, 2006 Report Posted March 3, 2006 Mix 40:1 (twice) with 91 and ride till you empty one gas tank on flat. Or you can do half and half of 91 and C12 but it has to be jetted at 340 or 350 and again empty one gas tank on flat. Then gradually break it in by doing 3 gallons of C12 and 2 gallons 91. Then to 4 gall of C12 to 1 gall of 91 to the end of full C12 racing fuel. 481234[/snapback] That has got to be the weirdest instructions for mixing I have ever read. Especially since you don't know his compression, mods, elevation, etc. If you jetted a bike with a 340 and it was stock at this altitude it would never start dude. Quote
crazywheelerman365 Posted March 3, 2006 Report Posted March 3, 2006 Mix 40:1 (twice) with 91 and ride till you empty one gas tank on flat. Or you can do half and half of 91 and C12 but it has to be jetted at 340 or 350 and again empty one gas tank on flat. Then gradually break it in by doing 3 gallons of C12 and 2 gallons 91. Then to 4 gall of C12 to 1 gall of 91 to the end of full C12 racing fuel. 481234[/snapback] Quote
mondtster Posted March 3, 2006 Report Posted March 3, 2006 For every person I have ever spoke with about this topic I have gotten a different answer. I have always used the following method for breaking in my top ends. It is pretty simple, but I haven't run into a problem doing it this way yet and I have built quite a few motors. During the assembly process I use liberal amounts of 2 stroke oil to insure that everything is lubed up well for the initial startup. I then mix a fresh batch of gas the exact same as whatever I normally run in the bike. I leave the jetting the same as it was previously as well (provided it didn't burn down from being too lean). I start it and let it run for a few minutes to bring the motor up to operating temperature. Then I shut it off and let it cool a little. At that point I get on it and ride it around the block taking it somewhat easy (no full bore, shift at redline stuff). If the motor hasn't had problems by that point they aren't going to. Check the coolant level and get on it and ride. If this is a brand new bike, brand new cylinders, or a real wild combo, I would probably suggest taking it easier to start with. New stuff needs to be heat cycled properly in order to allow the casting to relax. If they are beat on too early there will be problems. I've used the above method on bikes, sleds, quads, etc. with used, heat cycled cylinders with good luck but haven't owned enough new stuff to really worry about the castings. Also note that I run my premix quads and bikes at 32:1 and sleds with injection at ~50:1 so this may be richer than many of you guys run. Just my $.02 Quote
suzuki0702 Posted March 4, 2006 Report Posted March 4, 2006 different answer from everyone heres a simple one!! 2 tanks of premium gas, mixed with good oil (castor927) run two tanks through it and dont ever run full throttle for more than 3 gears...easy enough right?? good luck bud! Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.