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Premix

Posted: Wed Jun 08, 2011 6:11 pm
by thegoldensb
My oil pump stopped working I tried searching but can't find much I suck at finding key words. I have a 48 mm big bore kit how much should I use per gallon of gas and should i start getting highest grade gas to try and keep the octane up from the oil? Also how does oil get under the piston of I'm premixing in the gas? One other question how many miles should I break it in with and should I stay off full throttle to break it in?

Re: Premix

Posted: Wed Jun 08, 2011 9:13 pm
by Bear45-70
32 to 1

Re: Premix

Posted: Wed Jun 08, 2011 10:27 pm
by Wheelman-111
Greetings:

Agree with Bear's 32:1 suggestion.

Oil in a 'Smoker gets around the crankcase the same way whether it's injected or pre-mixed. The injection occurs in the intake stream, which probably resembles gasoline coming out of an Aerosol can. It gets picked up in the vapor and when it hits the relatively warmer crankcases, the mixture vaporizes and the oil turns back into droplets scattering hither and yon. A little stays in a puddle in the bottom, to be picked up by the flywheels and scraped off where it runs down a pair of channels to each main bearing.

Evidently enough makes its way up the bore to keep the rings from scratching the cylinder. Unlike super-high-output 4-strokes cooled by an under-the-piston-skirt stream of oil, the Spree makes do with good jetting and fan-forced air through the fins. Without an oil pump, you can't get the pressure needed for plain bearings or such high-pressure streams. Hence the ball-bearing mains on your scooter.

Re: Premix

Posted: Wed Jun 08, 2011 10:44 pm
by thegoldensb
Thanks for the info 32 meaning ounces per gallon? And when I put the big bore kit on should I put some oil under the piston it's completely dry it hasn't been started in awhile?

Re: Premix

Posted: Wed Jun 08, 2011 11:00 pm
by Bear45-70
thegoldensb wrote:Thanks for the info 32 meaning ounces per gallon? And when I put the big bore kit on should I put some oil under the piston it's completely dry it hasn't been started in awhile?
NO, 32 parts of gasoline to 1 part of oil or 1 oz of oil per quart of gas or 4 oz of oil per gallon.

Re: Premix

Posted: Wed Jun 08, 2011 11:40 pm
by Wheelman-111
Greetings:

The Service Manual in the Manuals section of this Forum has a chapter on engine assembly. I suggest you read there. It says something like "apply GN-2 to all sliding and bearing surfaces...." or words to that effect. I'm not sure what's up with your obsession with "Under the Piston", but except for the little-end bearing that you lube when you install the piston, that's not particularly where the oil goes.