New Engine Break In

That's a very good question, I'm not sure.

I know this has been answered a billion times, once to myself even but I feel like typing it.

First mix up a fresh tank of gas with a quality premix and good octane gasoline. Start your bike up and let it idle...if it won't hold an idle you've got a jetting problem. Try cleaning your air filter first then try to adjust the idle screw or the airscrew. My bike will idle till the cows come home without loading up and without stalling. Let this go for about 15 minutes, then shut it off. Allow the bike to cool for 15-20 minutes. This is a heat cycle. You want to repeat this procedure a few times..at least 2 or 3 more times before you ride it. After a few of those idle cycles, giving time to heat up and cool down properly, try some slow short rides. Run it through the lower gears without overrevving the engine and do this for a half hour or so then let it cool. I recommend using these heat cycles for the entire tank of gas. Doing this will ensure your bike is broken in properly and after that...start twisting on it.

That article pretty much says give it he** for the first 20 miles though?

That article pretty much says give it he** for the first 20 miles though?

I've been riding/racing for 30 years and I try to go trail riding the first time and then just ride it. While I try not to abuse it on the first trail ride I don't just putt around either. I've never had a problem doing it this way.

I didn't read the article but if you just start it up and give it he** it is a very good possibility you are going to sieze that motor especially if you have a forged piston in it. If the engine isn't allowed to warm up properly the basicly localized heat inside can and will make some things expand while others are still cold, changing tolerances and shape.

regarding break in I do the heat cycle thing as Jaypro states. As for the "give her he**" method I guess if it survives it its good to go.

jmics19067,

You need to read the article. IMO it didn't really say to give it he** but it did say not to baby it and listed very good reasons why.

Yeah, I've read this article before, and whats being said makes perfect sense. Its far from beating on the bike, but you do need some heat and pressure to make those rings seat right. Maybe Eric or Rich could comment here on what they think. Or maybe this is a good question for Professor Blair. IF we can't straightn it out here, try the advanced Tech form, all the smart guys hang out there.

that idea isn't new that is how haynes and chilton recomends break in of fourstrokes.

the first few steps checking all fluids, priming the oil pump , firing it up on a fast idle, check timing and carb settings, allow to reach temp. ,check for leaks ,shut off, cool ,double check all fluids and for leaks and then step 8

"Drive the vehicle to an area with minum traffic,accelerate at full throttle from 30 to 50 mph, then allow the vehicle to slow to 30mph with the throttle closed.Repeat the procedure 10 or 12 times.This will load the rings and cause them to seat properly. check for leaks"
step 9 " drive the vehicle gently for the 1st 500 miles change oil and filter....."

this part is only what I think and any comments would be appreciated
with fourstrokes the idea of loading the rings at throttle and then closing the throttle allowing intake vacuum to suck up oil past the rings to wash the minute debris off while seating them seems to me the standard. The idea falls short on two strokes though with the lack of oil bath to wash the cylinder down on the high vacuum low throttle part and the lack of true stroke of the piston for this to happen. The two stroke ring never really sees a moment where it is using vacuum trying to suck up extra oil so all of the grit has to be swept away instead of washed. Now it might not be friendly to the rings to do a slow break in but it would be a lot friendlier to the piston skirts having to ride along that grit.

things I belive I have seen.
After doing a few rebuilds and breaking in on different two stroke bikes,ranging from slapping in a piston and rings a couple of hours before I ride and wringing it out, to finishing the bike on Monday night and everyday until the weekend doing a heat cycle. The first thing is that it doesn't really take that long for the rings to set . Also I have noticed that the first way the piston will be scuffed more on the intake and exhaust skirts<not the four corner siezure marks but more like dirt foriegn object marks> and wear out quicker then taking your time.

Any thoughts or comments on that would also be appreciated.