Break In or Breaking?

[scatgo]

The two shops i looked into to rebuild my engine have the same break in procedure as in the Jonson manual except they say use 25:1 mix. The Jonson manual say 50:1. Anyone know why they would recommend twice the oil? 1980 35hp Johnson.

 

[flyingscott]

You always break in a motor with extra oil. The 25-1 suggestion is correct and after 10 hrs got back to 50-1. Find the johnson procedure and follow it.

 

[Scott Danforth]

. Anyone know why they would recommend twice the oil?.

because that is proper procedure for breaking in a motor so you dont blow it up.

 

[werewolf30]

Like the one said always use 25:1 on a new or rebuild and i run three 25 s 72 models and run mine at 25 to 32:1 , one ive used for four years gets run alot and had never been into , i lost the powerhead even using 25:1 i suppose because it was old and time to go,, still run 25:1 for awhile, im building a new one and will run it alot longer on rich mixture of oil to ensure it is protected good,, and after about 50 hrs i 'll do a carbon soak with gm top engine cleaner and blow it out and run it. my evinrude 25 was done like this and runs fantastic at 32:1

 

[Crosbyman]

oil is cheaper than powerheads....

 

[werewolf30]

crosbyman ,,, yeah the johnson was all oem never been into and tired, im building another powerhead to go on it , it gets run alot on the rivers , and i tweaked it abit so that probably helped the retirement quicker !!!

 

[racerone]

Where did you find that break in procedure ?----What manual ?----Perhaps it is for an oil injected motor .-----That would be oil from oil injection and 50:1 from the tank so that results in double the oil !!

 

[werewolf30]

I went off of what the older manuals had and tried it on a 72 e25 i did and it has worked out very well it has 135lbs compression on both holes, starts with about inch pull on rope or barely touch starter button, quiet and runs very well , and i'd rather run a little rich on oil than ruin a newly rebuilt powerhead, including parts and boring the cylinders it cost me right at 430.00 to do it. i believe it shows 50:1 on new ones,32:1 on the older ones like 70's thru 77 , im going to run this new one at 32:1 and add 1/2 ounce per gallon of gas . so far ive had no fouling of plugs and i eliminated the hose from lower of intake to top cylinder for fuel excess . idles great and wants to jump outta the barrel .

 

[racerone]

Nope ----all Johnson / Evinrudes can run at 50:1 since 1964 model year.----But yes with a little extra oil the motor will last more hrs.

 

[werewolf30]

i asked because the main roller bearings looked fine but rod bearings looked blue like lack of oil in the oem johnson 25 that blew up. and it had 125lbs of compression on both cylinders the day before it happened. id rather use extra oil than lose a powerhead again especially a newly built one

 

[racerone]

It blew up ?--What actually happened ?----These motors will run all day long at full throttle with good oil at 50:1 mix

 

[werewolf30]

I dont know what caused it except maybe old age ! the mains looked fine not loose, the rod bearings needles were blue like lack of oil ,,,?,,, im just temporarly trying out a 20 hp powerhead on it with the small excess fuel line from lower intake to side of top cylinder blocked off,, and run it about 50:1 maybe add 2 ounces extra oil to the six gallons and see what happens, i do know there are two types of piston setups one is blowback type and non blowback type, im using the non blowback type in the new build like the evinrude has. ive also been using the newer pennzoil oil blue in color. then after some running i'll swap the powerhead and put the 25 back on and disasemble the 20 and look at it and see if any bluing on bearings.

 

[racerone]

Are you referring to pistons with what are called --" pressure back " piston rings ???-----To me this all indicates that oil / lubrication in a 2 stroke is not well understood.

 

[werewolf30]

actually no , the only pistons available are the non pressure back type,, the lube is misted on the rods and the mixture is pressured some to the mains thru the hose from bottom to top , crankcase pressure is what mists the crank and rods on the crank. i was told the pressure back type was discontinued for low lube problems.