How do you break in?

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The following is my own break-in proceedure. I have broken in several 2 and four stroke engines including some ultralight aircraft 400cc+ two strokes.
I am not a certified expert, but I do have some knowledge with engines and the interviening 35 years of playing with them.

Having said that, I'll also say I haven't got one of the two prevalent Chinese manufactured engines just yet, but the following info pertains to most engines in general.

Break-in is a combination of heat cycling parts and allowing the rings to seat. This is taken care of by riding at moderate speeds followed by short periods of wide open throttle. Wide open throttle is necisary to seat the rings to bore properly. I saw a rather spirited discussion about this on the forums...this is not that kind of post.

A couple of observations- I see reading the forums that a lot of people are finding that these engines run better if the carbs are adjusted, and the intake gaskets are in order. If I were to break-in one of these (dax) e-bay engine, I would go ahead and set the carb and check the gaskets first. More on that later.

Another one is that the engines are suggested to be broken in with a 20/1 fuel mix. That's crazy, but I understand warranty issues. I'll just say use a good two stroke oil like Penzoil for 2 stroke air cooled engines, or one of the name brand synthetics (available at places like Wal-Mart in the lawn and garden/chainsaw/weedwacker area) and mix it in the 40 or 50/1 area AFTER BREAK IN.
If the carb is correctly set and the intake gasket(s) in order, begin break in....

To do an easy and proper break in, warm the engine until it will run with no choke then start down the road. Open the throttle to 1/4-1/3 and let it pick up speed for about 10 seconds, now back off the throttle and let it coast for about 10 seconds. Do that a few times. Next open it up to 1/2-3/4 throttle and let is gain speed for about 10 seconds, repeting the slowing proceedure as well. Do that several times then take it up to full throttle and let it gain speed for about 20 seconds, taking approx 30 seconds to decellerate each time. Increase the time you spend at WOT and decellerating until you are holding it wide open for longer than 30 seconds and you are about done.

Ride at moderate speeds with short runs of WOT until break in mileage is completed. You should notice an improvement in power and smoothness during the break in proceedure, and a gradual increase in performance for the next 100 miles or so.

Questions and comments are welcomed!
at least I voted :)

I am on my 2nd 70cc and am trying to go easy but vary the throttle
but 1st have to get my carb working right
don't sweat it joe, the break-in issue is a hot one, you'll get responses, maybe more than you want :devilish:

btw, you didn't add our trademark "i don't vote in polls" option :p
Hey, I did ONE pole, had to pull in a day ! EEEEEK.

Somebody ELSE stated it best - Simple Air, Spark, Fuel

Only speaking w/ 40 weedwhakers and ONE 40 cc experience, 3 things are most important.

1. Never forget the oil in the fuel, citykids without landscaping backgrounds may forget this cardinal rule, stuck hundreds of miles from the house, thinking "oh, a little siphoned gas from this pickup won't hurt." Manufacturer specs are best reference, STIHL does a warranty check on chainsaws and such, if you use WallyWorld Oil, they know it.....

2. The purpose of "break in" is to seat the rings, and there is a definite "point" where you know it worked. Weedwackers take about 150 miles. SOMEBODY ELSE said it best: It has to do with "compression".

3. The only "other" goofs you can do to FUEL are "water/moisture", diesel substitution.

The BEST preventative is to treat your bike/engine like your own personal horse, don't let others ride him/her.

4. (I Knew I missed one, thx BikerJoe in the 'other' breakin topic), Let the engine warm up, idle for a bit, before jumping on and hitting the throttle.
break in procedure

Dont forget bicycle break-in, too. after installing the kit, every so often step off the bike and tighten everything down.
once the bike gets over the initial 'wtf is this?'you'll need to do it less often.
i just ruined a good wheel, because i neglected to tighten the spokes.

once the bike gets over the initial 'wtf is this?'you'll need to do it less often.
rotflmbo. :D:LOL: That couldn't be more true. Seems my bike gets more solid every day and I trust it a little more.

I admit there are some days when I get home from work tired and worn out and don't let my friend warm up. I pedal till it starts and don't shut it off till we get home. That's good advice, I'll let it warm up.
This post randomly shows up as a New Post even though nothing has been added. db problem maybe. Perhaps this post will fix it.