breaking in new pistons?

demolition_x

Not After Fame & Fortune
i searched whats the proper way to go about this? i think i remember running 20:1 mix for the first time but how many tanks should i run through it at 20:1 before i goto 50:1? also are you suppose to keep the rpms low, i remember when i rebuilt my 125 it said go no higher than half throttle.

thanks
 

#ZERO

Beach Bum
Location
Florida - U.S.A.
During the first 10 gallons a 20:1 ratio of semi-synthetic oil mixed with the gasoline should be good and there should be NO full throttle operation. First idle the engine for about 10 minutes to ensure that the engine is properly warmed-up. Then begin varying the throttle position up and down, up to 20% throttle for a half hour. Then come back and let the engine cool off completely - it should be a good 30 min break. After it cools down, you may now ride it up to 50% throttle for another half hour or so. Then come back again and let it completely cool down again. Now you can go out and ride up to 90% throttle. Continue this for the remainder of the 10 gallons, never holding one throttle position for more than a few seconds. Do not run at a steady throttle position and do not go to 100% throttle. After your first tank of gas, replace your plugs with fresh ones. For the second tank, you may ride normally with one exception - do not hold it at 100% throttle for more than a few seconds. After the second tank of gas, you are completely broken in and may ride anyway you like.
 

Watty

Random Performance
Location
Australia
Thats a good way to do it, but I no longer follow that procedure.

I start with a normal oil/fuel mix (40:1 or 50:1)

tape something around your grip under the throttle so it won't go past about 3/4 throttle. It's a fool proof limiter that ensures that you don't go WOT.

I'll start the ski, let it warm up as I'm blipping the throttle on the trailer in the water. Next, I ride around up to about 1/4 throttle for 10 minutes, then 1/2 throttle for 10 minutes while blipping the throttle constantly. Come in and let it cool for 30 minutes and repeat. Once I get to about half a tank, I remove the limiter from the grip and do the same thing only with WOT blips for no longer than a second or so.

Once the tank is empty, I'm into it! I think the most important thing is the heat cycle of letting the engine warmup/cool down properly. I've run my last 3 engines in this way and have had zero problems. I'm not saying it will work for you, but it works for me.
 

Superjet3

Waterlogged
Location
Jersey Shore
On my new motor I rode it like I plan on riding it. First I let it get up to temp then have at it. I run my normal oil mix 15oz Klotz w 5 gal gas. Runs good and no problems. If a motor is build correctly it will not blow up. I have used this method with my last 3 motors with no problems. All 3 are still running strong.
 
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