Oil mix ratio for break-in

WFO

Member

Dec 27, 1999

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• Oct 15, 2002

• #1

I just got my cylinder back from Eric and have it re-assembled. My Yamaha manual says to mix my gas 15:1 for break in rather than the normal 32:1. It seems like I read somewhere that this wasn't necessarily the best thing to do, and I sure don't want to mess it up now. Any opinions

 

S

SuzookKING

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Aug 31, 2002

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• Oct 15, 2002

• #2

I break motors in on the ratio I plan on using, be it 20:1 or 32:1. I have yet to toast a top end during break in (in the past 18 years).

 

I

IrishEKU

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Apr 21, 2002

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• Oct 15, 2002

• #3

32:1 :thumb: BTW did you ever get that damper?

Phillip

 

Jaybird

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Charlestown, IN

• Oct 16, 2002

• #4

Heat and cool cycle of the motor is much more important, IMO.
Going with alot of oil when jetted for less can lean you way out.

Phillip,
Is that 32:1 recommendation a proffesional opinion, or because it's what you run? :)

 

WFO

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Dec 27, 1999

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• Oct 16, 2002

• Thread starter
• #5

The manual says 30:1, I rounded it off.

 

I

IrishEKU

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• Oct 17, 2002

• #6

Originally posted by Jaybird
Heat and cool cycle of the motor is much more important, IMO.
Going with alot of oil when jetted for less can lean you way out.

Phillip,
Is that 32:1 recommendation a proffesional opinion, or because it's what you run? :)

Click to expand...

Actually I run 40:1 and I'm still foggin' skeeters :) I'm going to lean the jetting out and fool with the needle settings. I need to run by the dealership and get some pages from the manual :| When am I going to bite the bullet and order Eric's book :think:

 

Jaybird

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• Oct 17, 2002

• #7

Ah ha, another "more oil, more smoke" guy. :)

 

I

IrishEKU

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• Oct 17, 2002

• #8

Originally posted by Jaybird
Ah ha, another "more oil, more smoke" guy. :)

Click to expand...

;) Actually it depends on which school of thought you are coming from, for me it's from that little mix cup I use and 40:1 is lower on the scale than 32:1. Depending on if your talking 40 parts fuel to 1 part oil, or 40 parts oil to one part fuel. I prefer the fomer, much less confusing on my part :confused:

 

Jaybird

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• Oct 17, 2002

• #9

Come on now, Irish....there is only one (correct) school of thought on 2 stroke ratio's. I've caught you posting more than reading and absorbing, haven't I, Mr. Butterbar? :)

 

I

IrishEKU

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• Oct 17, 2002

• #10

Originally posted by Jaybird
Come on now, Irish....there is only one (correct) school of thought on 2 stroke ratio's. I've caught you posting more than reading and absorbing, haven't I, Mr. Butterbar? :)

Click to expand...

:thumb: Yup you definatly have :) That's why I put it up there, because I posted one time about ratio's and the mathmatical equivalents in fractions, remember that one?

Phillip

 

R

Rockey5000

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May 6, 2002

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• Oct 17, 2002

• #11

I thought smoke and spooge were jetting, and not oil ratio?

 

Jaybird

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• Oct 17, 2002

• #12

If your jetting is spot-on at 20:1 and you change the ratio to say 50:1, then your jetting is no longer correct and it will smoke like a train. Jetting and ratio do work in relationship to one another, however chasing spooge with ratio is a bad move. When you get real close with your jetting but you may need to go a half jet size to be spot-on, in that case if there isn't a jet available, the remainder of the tuning can be done with tweaking the ratio. A slight tweak in ratio can help with atmospheric changes on race day as well.

Irish had recommended 32:1 for a top end, then said he runs 40:1 and "still smokes"...that would indicate that his school of thought on ratio was that if he runs less oil, he should smoke less...which is not correct and I had to poke at him a lil bit.