Break In How to properly break in a motor

Discussion in '2-Stroke Engines' started by 350zdrftr, Apr 27, 2009.

  1. 350zdrftr

    350zdrftr Member

    Ok yes I have searched for atleast an hour on here using the seach function. My new 80cc motor/66cc will be here Wednesday, I need to know how to properly break in the motor. This is the only thing I have found so far.
    Proper oil/gas mixture but whats correct ratio?
    Be easy on the throttle, no high RPM, just as in a car engine you have to give the rings time to seat.
    Anything else I am missing? Thanks to all I can really use some solid advice

  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Just curious who you bought it from?
    It's probably going to come with some kind of instructions......which
    may be incomplete or just wrong.......

    What I am telling my customers now for break in:
    Most people say start with 8 oz oil to a gallon = 16 : 1
    But 8 oz of oil is just too much in my opinion and experience

    so I start with 7 oz to a gallon
    I may even change that in the future to 6 oz

    7 oz oil to a gallon = 120 miles
    6 oz oil to a gallon = 120 miles
    6 oz oil to a gallon = 120 miles
    5 oz oil to a gallon = 120 miles
    Total miles = 480 break in
    4 oz oil to a gallon = 32 : 1 ratio is the final running ratio

    Don't use less than 4 oz to a gallon
  3. 350zdrftr

    350zdrftr Member, although I kind of regret it , I ordered the kit last Tuesday and it wont be here till Wednesday.
    Thanks for the guide for the ratio, one more question,
    Can I mix like 5 gallons at a time? or do I need to do it right before I am ready to use it? thanks
  4. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Well, initially you are going to be changing the oil / gas ratio every
    gallon so how could you mix more than a gallon at a time?

    How many miles do you ride a week?
    A gallon should get you at least 100 to 120 miles unless
    you ride really hard.....

    Gas goes bad especially the carp we have here in CA
    so i wouldn't mix more than you use in a week or less?

    There will be many "opinions" including mine about 'ratio" and "break in"
  5. 350zdrftr

    350zdrftr Member

    I was speaking after breakin if anything would happen to the gas/oil mixture if it sat for a while. I suppose it would just be easier for me to do a gallon at a time I will only be riding 35-40 miles a week btw . And do you recommend synthetic oil ? I only use it in my vehicles along with high grade gas and occassionally octane booster . Is any of that a little overboard for these motors? Thanks
  6. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    You don't want to use high grade gas ( hi octane)
    Use the cheapest regular gas unless you raise the compression ratio

    Do you know what the compression ratio is on the 66 cc 2 stroke?

    I don't recommend using expensive oil either.....
    Get 2 stroke oil for pre-mix and don't use 2 stroke marine oil
  7. BSA

    BSA Guest

    Compression ratio is around 6-1 so definately no need for high octane fuel. in-fact you would find better performance and less carbon buid up with lower octane fuel.

  8. bamabikeguy

    bamabikeguy Active Member

    Mixed gas separates rather quickly. 2-3 weeks in a gas can and you will have a performance issue. I once put new gas in my tank, but left the old gas in my two spare bottles, and hiccupped and sputtered all the way home.

    After 3 weeks, pour it in your car and mix a new batch.

    On the octane, when the big ethanol switch happened last June, I did a lot of checking, with distributors and chainsaw repair shops, they were recommending 89 octane, MAJOR brand (BP, Amoco, et al.) There is a big diff in the refining from the majors versus the discount brands re: ethanol, where the consistency/blend was better. (It had to do with "on site blending" that the discount guys had to do).

    Once that break-in is complete, you can try going down to 87 and make your own decision, based on how the engine performs.

    An easy way to vary the speeds is to "pick a target", 2/3 throttle to the big oak tree, 1/3 to the end of the fence, 1/2 to the red mailbox at the top of the hill. You just don't want to get in a rut on the throttle speed, nor hurry the break in.

    Make the engine "sing", by playing all the notes on the engine noise scale.

    I know 2 guys who got in a hurry on the wide open throttling, and they can barely hit 20 mph, while folks who get that cylinder seated properly say the engine gets stronger/faster as more miles pass by, because they did that varying throttling correctly.

    Our local Lowe's store sells a brand that comes in a squeeze bottle, enough to mix 5 gallons at 50:1 (I use the Japanese engines), a good oil at a good price.
    Last edited: Apr 28, 2009
  9. bamabikeguy

    bamabikeguy Active Member

    I read an article last month about the increase in business the lawn mower repair shops were having, since the ethanol switch last June, and the culprit was cheap discount gas, where they tested the blends, found them between 10-15-20% alcohol, no consistency.

    When you buy Standard or Shell 10% ethanol, you are guaranteed 10%.

    This is why we have to fight increasing the ethanol percentages, no-nothings in Congress are in Big Agriculture's pocket, irregardless of what the consumers/mechanics are reporting.
    Last edited: Apr 28, 2009
  10. 350zdrftr

    350zdrftr Member

    So I am getting mixed signals, should I be using 87or89 for break-in?
    Points so far
    1. Not high grade fuel
    2. Conventional over synthetic oil but not marine
    3. Vary the throttle for small trips
    This thing is a toy for me and not a daily commuter after break in I do plan on switching to higher compression, synthetic , higher octane, colder spark plug and nitrous . Thats just based on what I know about my car and all of those will work well together if done correctly
    Last edited: Apr 28, 2009
  11. bamabikeguy

    bamabikeguy Active Member

    I'm just passing on info that the owner of local Standard Gas Distributor gave me in a half hour conversation. Majors have a little device on the pumps that shuts the whole thing down if a half teaspoon of water gathers in the filter, cost the station owner $12 for the technician to click back on.

    (when you see the bag over the pump handle, they are waiting for the technician to come clean the filter).

    I was running 87 pre-June 2008, then some Standard 87 ran like cr*p, and I found out everybody switched (except Conoco), and they didn't put labels notifying the public.

    The Stihl chainsaw dealers recommended the 89, and that is what I use. Not as good as old 87, but nearly as good.

    Thats why I think you can experiment with 87 after 500 miles. Gas acts different in different locations, I don't know where you live, so 87 might really be best.

    91 and 93 octanes are out of the question.

    I agree with you on the conventional....synthetic after maybe 1,000 miles, or even Amsoil once it hits peak performance. That is what I heard long ago.

    My problem is I'm constantly breaking in new engines, so on my own personal Tanaka, the only time it gets Amsoil is when its out on the long distance rides, mixing as I go.

    But it is up in the >5,000-6,000 mile range, I'm sure.
    Last edited: Apr 28, 2009
  12. Mountainman

    Mountainman Active Member

    have fun as you break that MB thing in

    #3 above -- very important -- up here on top the mountain

    not going above 2/3 throttle for a while

    a nice slight variation of speeds from between 1/3 to 2/3 throttle

    first four or five rides -- 20 minutes each -- cool down period of 15 min inbetween

    a nice rich oil to gas mixture while breaking in

    these thoughts regarding proper break in change a little over time
    but -- I think you have the idea

    have fun as you break that MB thing in
  13. echotraveler

    echotraveler Member

    hey guys thanx for the advise!

    i have in my tank almost a gallon, so i poured the 2 cycle oil from sears, alsmost the whole thing, a little more than what the instruction think it worked great, good sound motor, and no bad smoke either.

    but i did pour 93 octane gas....i guess its not gonna make a big differece, does it?
  14. bamabikeguy

    bamabikeguy Active Member

    The reason I can't honestly say is I've never done that....OR, the one time I did it, in Oberlin Kansas, I got a bad batch of generic 91 and vapor locked to the next town, where I dumped it at a small engine repair shop.

    But my mind was scrambled on that whole 3,000-5,000 ft. altitude, I was blaming the gas for the duration until I dropped back into dead armadillo Oklahoma (under 3,000 feet range).

    Next tank, try 89, just a tad leaner, see if YOU feel a difference. You can add a bit more oil, but you can't subtract it.

    Anything that exceeds recommendations during the break in is good, EXCEPT thinking 91-93 is "better".

    Its not, and I forgot everything I learned in High School chemistry/physics, as to why that is so.
  15. 350zdrftr

    350zdrftr Member

    The gas in my area seems to be pretty good so I am going to try 89 at first and see how it reacts to it. If i feel like it does well i will step it down to 87 . I hate the thought of using 87 though I guess it just something in my head cause my car only takes 93 and it just trips me out!!!!! lol , so does that sound like a descent plan?
  16. bamabikeguy

    bamabikeguy Active Member

    Like I said, and this may be a**backwards, 87 burns hotter than 93, it takes hi-tech computers to ignite 93.

    87 is more like a cheap chinese firecracker, sssssss-pop.

    I'll stay at 89, but that is apples and oranges, stick with the one that works best.

    The diff is like .08 cents either way.
    Last edited: Apr 28, 2009
  17. 350zdrftr

    350zdrftr Member

    sounds good , then I should be able to tell a difference when I switch to 87
  18. Junster

    Junster Member

    High octane gas takes longer to burn than low. So a high compression engine the mix burns slightly slower and stops pre detonation. Not really a problem for these motors. But higher octane fuels usually have less ethanol to maybe better for us. As far as the original topic. A company I looked up that professionally breaks in 2 cycle jetski's for racing teams sez. Start and Idle run about 3-5 minutes shut down and allow to completely cool for at least 20 minutes. Drive in just above Idle for 5 minutes shutdown 20 minutes. Again with tiny throttle blips. It goes on and and on. I did this with a Polaris jetski it did work but it took all day and half the next (the ski cost 11k not $150). I think Mountain Man is about right with his suggestion. I would however do the initial 5 minutes idle then shutdown till cool. It sets the bearings. Good Luck, most say to not use synthetic till after it's broken in.
  19. Mountainman

    Mountainman Active Member

    should you be able to tell the difference ??

    tell the difference ?? -- hard to say

    but just a note
    most of these little engines are made to run best on reg 87

    it's a good THING
  20. 350zdrftr

    350zdrftr Member

    exactly if i run 89 to be safe, then i should be able to tell a difference when i switch to 87, but its ok i am just starting and sticking to 87