2 stroke Considering Oil-injection to Pre-mix....Mix Ratio??O

Discussion in '2 smokers' started by lake_harley, Dec 21, 2011.

  1. Quickv4

    Quickv4 Pro Turd Polisher

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    Keep the oil injection dude, if it ain't broke don't fix it. Like others have said, it is wonderfull if you plan on riding the bike anywhere serious. All you have to do is top the gas tank off at a fuel stop, check your oil level once in awhile, and ride on. Carrying a bottle of 2stroke oil and measuring untensil stinks. Leave premix for racebikes or vehicles like mopeds where you dont have to fuel up quite as often. :thumb
    #21
  2. lake_harley

    lake_harley Been here awhile

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    Lotsa input...thanks to all. I had already been thinking the way Bud Tugly suggested, and plan on finding/building a smaller "race inspired" tank....preferably aluminum.

    For what it's worth....the bike has been stripped, blasted, freed of some excess tabs and such, and the clean up phase of the project is underway. I'll be priming and painting it (the frame swingarm etc.) with my electrostatic paint system...probably light gray, wheels will be medium gray, and the tank and a few other things will probably end up orange of yeller. Tires (Dunlops with a kinda rough dirt-tracky looking tread pattern, even though they're a little big) are courtesy of my old Sportster that recently got new rubber. Airbox was toast, so it's just getting a K&N pod filter on the case inlet flange where the tube attached from the airbox.

    I know....it's not happening unless there are pictures, so one of these days, when I've made a bit more progress I'll post it up in another thread. I guess I'll start one, or would it be OK to post progress in the street/flat trackers thread already going?

    Thanks again for the input.

    Lynn
    #22
  3. peter650

    peter650 Been here awhile

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    Bin the oil injection it's crap. Premix is the only way to go, if you want to make 100% sure, your motor is getting oil. Most oil injection systems,have a cable that will feed more oil as your revs go up. The cable will fuk up starve your motor of oil, and bang. If you are to lazy {stupid} to pre-mix oil, buy a 4 stroke.
    #23
  4. Shocktower

    Shocktower Long timer

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    BOOO to the Aussie they are crazy any way :lol3, Premix is a PITA IMHO oil injection systems are fine I am voting for keeping it simple, just one brain fart and KABLAAAAMMMOOOOOOOOOOOO ( David Hobs reference) :cry
    #24
  5. Foot dragger

    Foot dragger singletracker

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    A more stark race bike look............and also be sitting at a gas station every time you put gas in figuring out how much oil to mix with the gas. Or have an automatic pump do it?
    Looks are only looks. Put a number plate over the oil reservoir and forget it.
    #25
  6. Foot dragger

    Foot dragger singletracker

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    Spoken by yet another know-nothing ADV'er. Ive had oil injection pumps go 40,000 miles with no problems,theres a cable,it moves when you turn the throttle,the pump squirts oil,very simple. They had it figured out a long time ago.
    #26
  7. fastdadio

    fastdadio Still gettin faster

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    This post is just wrong on every level. Tell us Peter.650, would you be willing to list the year, make and model of the many oil injected 2t's you've owned, and on which you base your vast experience?
    #27
  8. biggurn

    biggurn Yes, it is BIG.

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    As certified Polaris Techs, between myself and my father, we have worked on and sold hundreds probably thousands of oil injected 2-strokes over the last 20 years, and have seen only a hand full of engine failure where the pump was blamed, one was on a brand new unit where metal shavings where found to be of fault, the others where all the owners fault (i.e. not changing the inline oil filter or using the wrong oil type, i.e. Spectra (a PRE MIX ONLY OIL) in an injector or amsoil, doesn't work well, especially in injectors- Polaris would not honor warranty on any unit with a burn down while running it, regardless of what amsoil says). So, once you chose an oil, make sure it is compatible with use in an OIL injector! If not find one, everyone will tell you what they think is best, in my KTM 300 MXC i run Motul oils, low to no smoke and a pleasant smell. Most pre-mix type oils are not intended for use as injector oil (it’s a viscosity issue). While Motul makes an injector oil, In my old Polaris ATVs I run Pennzoil injector oil, it is cheap and readily available, if i still road them Iike I did before kids, then I'd run Motul in them. While Pennzoil is Not my preference, for bikes that are almost 30 years old and rarely get ridden anymore, it works well. While on some sleds and bikes over the years I have removed the oil pump, it has always been because of extensive engine modifications where it was determined that the stock pump would not meet the needs of the modified engine. In the end, no matter what route you go (keep injector or toss it) chose a HIGH QUALITY oil and STICK with it as this has been proven the best thing for a 2 stroke engine. But just my $0.02 and like the rest of the inamtes here, what do I really know???
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    #28
  9. anotherguy

    anotherguy unsympathetic

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    My (former) landspeed record holding RZ 350 has 40K+ on the original oil pump. And I set the record without worrying if the oil ratio was enough at the top end. Just pour some VP MR2 (R.I.P.) in the tank and kick. I do set it up a tad rich on oil delivery. More oil+race fuel=more power :D
    #29
  10. peter650

    peter650 Been here awhile

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    I have had 2 strokes for the last 35 years. I rebuild all my own motors. What i am trying to tell you , there is a reason why people by pass the Oil-injection {and it's not for the fun of it}. Pre mix at a pump how hard is that????? Baby bottle of oil put your fuel in tip in the oil, and give it a shake. What is the drama with that? If you can't do that should you own a 2 stroke? Which is what this thread gets down to. Some people should just never own 2 strokes. You have to check your ring gap, you have to decarbon your motor, clean out your pipes/mufflers, if you have a bridge in your exhaust port drill holes in your new piston,heat up your head gasket till it's cherry red then put it in water so you can reuse it,{Good thing about Bultacos}, jetting from summer to winter. Doing all this is 100% fine, but tipping some oil in your petrol tank is just way to hard. Pre mix is easy i was doing it when i was 10 years old, it works 100% of the time.
    #30
  11. Shocktower

    Shocktower Long timer

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    That explains it




























































    :hide :D
    #31
  12. scrambler73

    scrambler73 Been here awhile

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    well.....until you stick a crank and later realize that the bike you decided to premix has an oil injection system designed to directly feed oil to the main bearings by means of slingers/diverters.
    And running premix (especially on non-slotted-rod cranks) without removing the slingers may actually BLOCK oil from reaching the big end and main crank bearings.

    One of the most reliable things about the majority of 2 strokes is the freaking oil injection system. I know Kawasaki and Yamaha to have ridiculously reliable O.I. systems.

    For race purposes...sure, then Premix.. but for street use. Run the pump.
    #32
  13. anotherguy

    anotherguy unsympathetic

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    Hey who am I to stop anyone from doing what they want? Just a suggestion.
    #33
  14. peter650

    peter650 Been here awhile

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    You are taking what i am saying out of context and you know it. But i have modified Suzuki GT750 crankcases to run premix, got 95hp @ sea level.
    #34
  15. anotherguy

    anotherguy unsympathetic

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    Well then you know how it is around here. Pics or it didn't happen. :1drink
    #35
  16. scrambler73

    scrambler73 Been here awhile

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    nah.. Im not taking anything out of context. You are saying that oil injection systems are crap, and I, along with the majority on here are saying that there is nothing "unreliable" about oil injection systems on 2 stroke motorcycles.

    The way your sentence above is written ("I have modified GT750 crankcases to run premix and got 95hp"), makes it sound like by solely switching to premix, the HP of the engine doubled.....

    a Polaris 800 twin puts out 150 hp and has one of those "unreliable" oil injection units. So if a guy pulls the oil injection, and starts mixing gas and oil, will the engine then be in the 270-300 HP range?

    For the last 10 years, my main "riders" have been OLD two stroke street bikes. You name it, RD's, RZ's, Suzuki GT's, Kaw Triples, Honda NSR250's, NS400R, etc.....
    ALL are using the injection system (some 40+ years old:eek1), and I wouldn't hesitate to jump on any one of them and ride across country. The last mechanical thing I would worry about is the injector pump....
    #36
  17. gplracing

    gplracing Adventurer

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    Pumps work great, I've only ever had one fail and that was on a RZ350 where the plastic drive gear bust. If it's a road bike I'd say stick with the pump, if your going off racing bit of a different story.

    The only thing to watch out for with some of the twins is the oil delivery can differ between cylinders at times.

    Glyn
    #37
  18. fastdadio

    fastdadio Still gettin faster

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    Why? Those bikes are known for going tens of thousands of miles without drama.
    #38
  19. peter650

    peter650 Been here awhile

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    Why do you guys think it's better, to run premix for racing???
    For the life of me, i can't understand what you guys find so hard about pre- mixing.
    Anyway you want to trust your motor to a 40year old pump, because you are to lazy to tip abit of oil in your tank, when you fill up. That's up to you.
    Ask yourself this, if oil-injection is so great why didn't yz,cr,kx,rm,it,pe, i could keep going but you get the idea come with it.
    #39
  20. gplracing

    gplracing Adventurer

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    Because it's a known quantity, if your setting the engine up with EGT, det counter and or CHT you don't want anything else that could influence what your looking for. Plus it's a constant oil ratio what ever jet size you use, you'd have to change a jet and the oil ratio to give you the same ratio you had before. Which seems hard work in my eyes lol.

    I have nothing against pre-mix thats all I use to be honest, but IMO for a stock to slightly modified keep it simple.
    #40