'86 Spree PREMIX recommendation. Thanks.

[BFD'86]

Hi Guys, I'm working on a friends '86 Spree (that he picked up off the curb, slated for the trash truck). Amazingly it was complete, minus the ignition key, has 140 lbs compression, spark and actually runs. My question is, I would like to bypass the oil injection system and just run premix just to play it safe. Whats the general consensus on the ratio? 32, 40, 50:1? Thanks in advance. Steve

[Meatball]

32:1 on these old motors....newer 2-strokes like 40:1, 50:1 or even higher.....these like 32:1

[eclark5483]

I agree, yet disagree. 32:1 is just fine provided you are using SB50 reeds, not NQ50. You will saturate out at 32:1 with a stock reed setup. Best safe level is 40:1 as a starting point if attempting to run without a pump. When you say you want to run premix to "PLAY IT SAFE" I question when you have ever heard of a Spree oil pump failing in the last 30+ years?

If I personally, wanted to "PLAY IT SAFE", I would replace any worn components in the questionable part rather then try to emulate it's function to an already weakened carb system. So I honestly can't see your point of view as to what "PLAYING IT SAFE" means. You're dealing with a Spree, it's picky.. know what you are getting into by removing that pump, the Spree WILL protest.

[BFD'86]

Hi Guys, Thanks for the replies. Well, when I say "play it safe", having to rely on a separate mechanical device to provide an important function, ie. lubrication, for me seems like an unnecessary risk. It very well may be a robust and reliable devise and perhaps never fails, but it's still a mechanical device.

I know nothing about a Spree or the history of the pumps, but I've been using 2 cycle equipment for nearly 40 years. Heck, I've got chainsaws that have over twice the displacement and run probably at more than twice the revs and they don't need oil injection systems. To me it seems like an oil injection system is designed more for convenience than for necessity. It certainly is a lot easier to just pull up to the gas pump, get your gallon of gas and be on your way (and occasionally topping off the oil tank every couple hundred miles, or whatever the range is). At the same time, the manufacturer doesn't have to worry about whether or not the owner knows how to correctly measure 2 cycle oil at the correct ratio in order to provide the necessary lubrication. Certainly not rocket science, but for little Johnny or Missy, might be a problem.

So when you say the Spree has a "weakened" carb system, is "picky and will "protest", what does that mean? The carburetor is fairly simple in design, really nothing to it. An idle circuit, removable main jet and emulsion tube, float and needle. No pump diaphragms or other internal gaskets to go bad.

Anyway, enough with all that. I was just hoping to get the correct ratio. Best to start low and go from there; better to foul a few plugs then to score a piston. Thanks. Steve

[Meatball]

Split the D....36:1

[Jonadz]

Split the D....36:1

Whoa Lorena Bobbit! No splitting the "D"!

[eclark5483]

What I mean by that, is the Spree likes a lean mix at idle and enrichens as the pump increases RPM. The pump runs on a linear plane and increases output as the engine needs it. Just running a straight mix will give you a horrible takeoff. But don't listen to me, what would I know, you've been using 2 cycle equipment for over 40 years so obviously each one is the same and you know better then I do. Don't know why you bother even asking quite honestly with all that experience, but go ahead and run it with an over saturation of oil, I won't try holding you back.. good luck with that.

[Wheelman-111]

Greetings:

Sprees in particular are "Picky" because the Pilot jet is very small. In order to work at all, there has to be negative pressure in the intake tract and carb throat. The relative vacuum hurries the flow from that tiny pilot hole just enough for it to run, then make the transition to the needle and Main jet. If you unplug the airbox, or even if you try to run it without a filter, it runs horribly. (Or so I've repeatedly read...) The pump varies the oil content of the fuel. Somebody Very Smart had to sit down and calculate the oil output of the pump at every operating RPM to design a pump that would supply that correct amount.

Everybody I know running a 2-stroke Honda uses 32:1 if the pump is deleted. Yes it's a lot more convenient to keep the pump, but if you delete it I recommend you do the same. If you use more oil than that, it may run hot, because the mixture ratio off-throttle will be considerably too lean.