How long (miles/gas) should breakin take

Nomad

New Member
Aug 4, 2008
188
0
0
U.S.A.
I have read the installation manual about breakin, and find some conflicting info about engine breakin.

One sentence says after the first 50km the other says after the first 500 km... anyone know which it is?... how much gas run through? how many miles. And after the breakin period what is a safe mix ratio... the manual calls for 16 to 1 for breakin ...what about after that?..
 
Last edited:

~macaddict~

New Member
Jul 29, 2008
59
0
0
Well on all of mines the break in was in the first gallon or gallon 1/2 running 16:1 fuel ratio. After that I run 32:1. Hope this helps.

~Mac~
 

Nomad

New Member
Aug 4, 2008
188
0
0
U.S.A.
Mac, thanks .. I have already run about a gallon through mine, then I put some 32-1 mix in the tank without remembering it was for my weedwhacker, and it really ran alot better.. maybe it's time for 32-1...
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
Initial break in (rings) happens in the first 1/2 hour of operation. The engines seem to get "broken in" around 300 miles.
 

Nomad

New Member
Aug 4, 2008
188
0
0
U.S.A.
Initial break in (rings) happens in the first 1/2 hour of operation. The engines seem to get "broken in" around 300 miles.
Bikeguy Joe, do you think I should continue to use 16-1 till about 300 miles is on my engine?.... if the rings are "seated" at 1/2 hr is it ok to go to 32 to1?... thanks
Bob
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
Normally 20:1 is more than enough (modern) oil for break-in.

I run 24:1 afer that for the engines since I don't take them apart and mic the wristpin, which always seems to be on the loose side.

32:1 is O.K. if you run full synthetic and don't rev 'em up too hard.

Run a tank of 16-20:1 then go to 24:1 for a couple hundred, after that you are on your own.

Break-in of the rings (also called "seating" happen very quickly once the engine is started.

The best proceedure for seating the rings is to fire up the bike, warm it slightly, then ride it varying the throttle postition and engine rpm contantly. Generally, you want to accellerate for 10 seconds, then back off a little and SLOWLY de-cellerate for 10-20 seconds, repeating this cycle for several minutes, each time with slightly more throttle so in the 10 seconds, your rpm is higher each cycle.
 

essah

New Member
Jun 17, 2010
4
0
0
LA
I'm trying to understand this break in thing a little better. I just installed my first friction drive kit. It is not going as fast as I would like I started off with a 32:1 ratio. It goes up hills really slow. When I'm not on a hill it goes around 15-20mph. Is this because the engine needs to be broken in or is it something else. I've done a lot of checking to make sure that my friction roller is properly places on the wheel it has a solid grip. If it is not this what else could it be.
 

chrisme

New Member
May 30, 2009
423
0
0
Maine
What about breaking a new top end. My bottom end has thousands of miles on it and ran awesome when the ring pin came loose. So do I need to be as extensive in my break in since it's just rings?
 

nolan_speed

New Member
May 31, 2010
30
0
0
Seattle, WA
If your bottom end is already broken in and you're just breaking in a fresh top end, I'd go to 16:1 for only a tank or so, warm the thing up gently, then ride HARD for a while. Alternate the engine speed a bit but mostly ride really hard to seat the rings, after that tank you can go to 25:1 or even a bit leaner if you wish and ride as normal.

Everyone has their own opinions as to break in but this is mine. Rings break in quickly but should be run hard to do it properly. On a new engine you're balancing running the engine hard to break in the rings quickly vs running it easy to break in the bearings and lower end gradually. Since the bottom end is already broken in, I think you can just run it hard to break in the rings without worrying about the bottom end.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
Do not use 16:1 for break in or any other time unless you are using sae30 wt motor oil for your mix.....and why would we do that? It's not 1951 any more.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
I'm trying to understand this break in thing a little better. I just installed my first friction drive kit. It is not going as fast as I would like I started off with a 32:1 ratio. It goes up hills really slow. When I'm not on a hill it goes around 15-20mph. Is this because the engine needs to be broken in or is it something else. I've done a lot of checking to make sure that my friction roller is properly places on the wheel it has a solid grip. If it is not this what else could it be.
Sounds like you are on the right track....give it a little time.

Also, depending on what engine you have and your all up weight, that may be all you are going to get on a hill.
 

Mojo

New Member
Dec 26, 2011
60
0
0
33755 Clearwater Florida
Bump Bump Bump, sorry for bringing a post from 2008 back into play, but i figure what the **** right?. I wanted to know what you guys think about what i am doing with the engines i use. i ran 32:1 for break in, 400 miles was my break in period, after the break in period i ran 40:1 for about 200 miles to get my engine ''use'' to the new oil range, after the 200 miles i went up to 50:1. i am using currently 50:1 in BP's superb gas, with a VERY cheap corner store oil for 2 cycle engines i pay 1.49 for this oil. I have over 8000 miles on this bike/engine i am running the standard 44T rear and 10T drive, high intake air filter ADA i think, a custom exhaust, I took a hack saw to a pocket bike exhaust, right where the expansion chamber section of its exhaust extends out to the silencer at the end of the exhaust and cut it off to allow 100% of the sound and i am guessing around 20% more air flow, standard 66cc Discontinued R.A.W brand motor straight head (not a slant fire) kit packaged CDI, kit packaged CARB. i know no one here would EVER trust there HT engines to anything more than 40:1 as its ''not safe'' most would say nothing more than 32:1 i am sure, i got this engine off craigslist used as she was my first and a trail and error type deal for me, the guy who had it ran it for 2 days a total of 30 minutes in both days and his bike frame cracked at the welding at the ''header tube?'' where the forks go into the bike frame so he sold it to me for 50$. With the 32:1 oil she went a total of 32 mph, when i switched to 50:1 i was clocked by the local police doing 49 mph, the only thing i changed was the oil to gas. i live in florida and this engine has seen some seriously hot Weather while running 50:1... i check/clean my piston, piston head/walls very often, likely around every 200-300 miles i check and clean if needed, i noticed the less oil i have in the gas, the less carbon deposits i find on the piston. get back at me with some comments and thoughts il be checking! dnut
 
Last edited:

rustycase

Gutter Rider
May 26, 2011
2,746
0
0
Left coast
WoW !

"clocked by the local police doing 49 mph"

That is exceptional performance.

I don't think we're gonna be able to vote you to be our goodwill ambassador, though.

Here in Kalifornia they'd probably impound my motorized bicycle for doing that, and I'd be tied up in the court system for a loong time!
rc
 

motor_bike_fanatic

New Member
Jul 26, 2011
377
0
0
Pennsylvania
I run 32:1 for break-in and 16:1 after that, full synthetic. That being said, the best advice is to check the color of your spark plug, and that will tell you if your mixture is right. you are checking the color of the prong and the electrode. During break-in, it will almost definitely be black, because you are adding more oil than what your engine needs, but that's what you're supposed to do. after break-in, the color should be anywhere from tan to light chocolate. white is too lean, black is too rich. if you're a little too rich, moving the c-clip down on the throttle needle will probably help. if you move the clip all the way down on the needle and you're still running rich, use a little less oil in your gas. if you're running lean, do the opposite. I check my plug regularly, and my spark plug is a light chocolate. My engine is a year old with no issues. I did have to move the c-clip all the way down on the needle, but thats not a big deal.
 

Allen_Wrench

Resident Mad Scientist
Feb 6, 2010
2,786
4
36
Indianapolis
I think mine happened around the 350 mile mark - BUT...I'd venture to say you may find subtle difference between each engine, especially considering CCs and place of manufacture. To describe it: it's as though the engine reaches a point where it just starts running better and better over a few days. At that point, if you try going from a 20:1 or 32:1 fuel mix down to a 40:1 fuel mix, you'll start noticing a positive difference in performance.
 

tooljunkie

Member
Apr 4, 2012
663
4
16
Manitoba,Canada
16:1 break in,24:1 intermediate,32:1 after about three tanks,then full synthetic,like amzoil.optimol may be the one i end up using due to availability.