Stock Oil Pump Delivery Ratio

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Bear45-70
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Re: Stock Oil Pump Delivery Ratio

Post by Bear45-70 »

SuprasNsprees wrote:For Spree owners with the CT manifold, it costs $4 and 5 min time to retain the stock pump

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I just Add a tiny bit in the tank every fill up
Doesn't even take that long if you have an OKO 21 mm carb that has a nipple already on the back of the carb.

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Re: Stock Oil Pump Delivery Ratio

Post by SuprasNsprees »

that DOES look sweet. ive got a similar carb, just not with that handy nipple
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Re: Stock Oil Pump Delivery Ratio

Post by yurself »

Anyone see a problem running the sa50p pump and mostly premix?
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Re: Stock Oil Pump Delivery Ratio

Post by Bear45-70 »

yurself wrote:Anyone see a problem running the sa50p pump and mostly premix?
WHY?
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Re: Stock Oil Pump Delivery Ratio

Post by yurself »

I just want to make sure its safe. I have heard the sa50p pump doesn't put out enough oil so I didnt tie it open and add 2-3 ounces of premix.
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Re: Stock Oil Pump Delivery Ratio

Post by Bear45-70 »

If you are running the pump and premixing, then do tie the pump open, but I do not think your pump has a cable to it. But if the pump runs 70 to 1 then all you need in the tank is 70 to 1. You are aware that when you go to pre-mix you need to up your main jet one size.
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Re: Stock Oil Pump Delivery Ratio

Post by JJ Joseph »

Trafficjamz wrote:how is there no oil flowing to the engine going downhill, with a premix setup?
There is no oil going to the engine when the throttle is CLOSED (e.g. when running downhill on closed throttle). With the throttle closed, the needle drops into the jet orifice and the flow of premix is shut off. Therefore the engine is starved of oil. You're OK for a moment only. Then your hot engine is seriously scraping metal-on-metal as the oil vanishes. This is what 2-strokes used to be like in the OLD DAYS. Since the invention of the oil pump, this shouldn't happen any more since the oil is still injected when the throttle is closed. Without the oil pump, your engine is oil-starved when running downhill. Only someone with more dollars than sense would run a Dio without an oil pump.
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Re: Stock Oil Pump Delivery Ratio

Post by Bear45-70 »

JJ Joseph wrote:
Trafficjamz wrote:how is there no oil flowing to the engine going downhill, with a premix setup?
There is no oil going to the engine when the throttle is CLOSED (e.g. when running downhill on closed throttle). With the throttle closed, the needle drops into the jet orifice and the flow of premix is shut off. Therefore the engine is starved of oil. You're OK for a moment only. Then your hot engine is seriously scraping metal-on-metal as the oil vanishes. This is what 2-strokes used to be like in the OLD DAYS. Since the invention of the oil pump, this shouldn't happen any more since the oil is still injected when the throttle is closed. Without the oil pump, your engine is oil-starved when running downhill. Only someone with more dollars than sense would run a Dio without an oil pump.
So in your theory of 2 stroke engine function at idle there is NO fuel flow? WRONG!
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Re: Stock Oil Pump Delivery Ratio

Post by JJ Joseph »

Bear45-70 wrote:So in your theory of 2 stroke engine function at idle there is NO fuel flow? WRONG!
Did I say "at idle"? Sorry, but you're not paying attention again. I think I said at closed throttle. You get 2 points for trying, though.
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Re: Stock Oil Pump Delivery Ratio

Post by Bear45-70 »

JJ Joseph wrote:
Bear45-70 wrote:So in your theory of 2 stroke engine function at idle there is NO fuel flow? WRONG!
Did I say "at idle"? Sorry, but you're not paying attention again. I think I said at closed throttle. You get 2 points for trying, though.
Closed throttle means idle mixture in every engine I've ever run, regardless of actual engine RPM. So once again it is YOU who has no understanding of engine dynamics. If the throttle is closed, the only circuit feeding fuel is the idle circuit with a carb, hence at idle. You real are not very bright and an extremely closed minded thinker.
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Re: Stock Oil Pump Delivery Ratio

Post by paulpauly7 »

sorry to say it jj but bear is right when you are going down hill with the throttle closed if there is no fuel flow how does the engine keep running?
when the bike is at idle with the throttle closed your bike runs

throttle closed at idle or coasting down hill the carb still flows gas thats how they run.If you are premixing fuel and oil then when ever the engine is running you are getting oil

Is this really to hard to comprehend or have you realized that you are wrong and you have made such a fool of your self arguing about it you now to scared to admit your wrong
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Re: Stock Oil Pump Delivery Ratio

Post by Wheelman-111 »

Greetings:

Quoth JJ:
With the throttle closed, the needle drops into the jet orifice and the flow of premix is shut off.
You are correct in that there is no flow through the main jet. You are not correct in stating there is no fuel flow to the engine. The idle circuit and the Pilot circuit are both spraying a good bit of mixture down the carb throat in the high-vacuum setting created by the closed slide. If that Pilot jet is sized adequately, the flow is sufficient both to prevent the coast-down overheat and to supply the little extra oil that the non-power-producing top end needs to keep itself slathered. Remember two-strokes keep a Puddle in the crankcase in reserve anyway for those long downhills. Unless you're coasting down Haleakala, calamity is averted. Witness just about every Hawaiian modder - Pumps are scarce on the hottest builds, and they seem to do just fine. You've had success keeping the stock pump. Good for you. But suggesting that it works for everyone just isn't good advice.
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Re: Stock Oil Pump Delivery Ratio

Post by JJ Joseph »

paulpauly7 wrote:Is this really to hard to comprehend or have you realized that you are wrong and you have made such a fool of your self arguing about it you now to scared to admit your wrong
2-strokers arguing that the oil pump is irrelevant are ignoring developments in 2-stroke technology. The oil pump was developed by Yamaha to overcome a major defect in 2-strokes: premix 2-strokes are dirty and unreliable. With premix methods, your engine will be either over-oiled or under-oiled with the same mix. When your engine is under-oiled during closed throttle ops (high-speed, downhill) you will cook the moving parts. If you are over-oiling during acceleration, your engine will accumulate excessive carbon deposits. Accumulated carbon increases wear in the engine and decreases performance. Many racers don't worry about carbon because they run at continuous wide-open throttle & don't mind rebuilding their engines. The people on this forum aren't racers. They're low-budget performance enthusiasts who mostly don't know how to do a 2-stroke rebuild. The oil pumps were added by clever Yamaha & Honda engineers for one reason: increased engine life & reliability. The difference in reliability was so huge that most "premix" bikes like Bultaco & Montesa went out of business after Yamaha (and Honda) introduced oil injection. If you figure you know more than Honda, Yamaha, Suzuki, Hirth, Rotax, BRP, and the aircraft engine builders that insist on oil pumps for reliable engine operation, there's not a lot the rest of us can do to save you from self-destruction. As has been said before, you must have more "dollars than sense".
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Re: Stock Oil Pump Delivery Ratio

Post by Bear45-70 »

JJ Joseph wrote:
paulpauly7 wrote:Is this really to hard to comprehend or have you realized that you are wrong and you have made such a fool of your self arguing about it you now to scared to admit your wrong
2-strokers arguing that the oil pump is irrelevant are ignoring developments in 2-stroke technology. The oil pump was developed by Yamaha to overcome a major defect in 2-strokes: premix 2-strokes are dirty and unreliable. With premix methods, your engine will be either over-oiled or under-oiled with the same mix. When your engine is under-oiled during closed throttle ops (high-speed, downhill) you will cook the moving parts. If you are over-oiling during acceleration, your engine will accumulate excessive carbon deposits. Accumulated carbon increases wear in the engine and decreases performance. Many racers don't worry about carbon because they run at continuous wide-open throttle & don't mind rebuilding their engines. The people on this forum aren't racers. They're low-budget performance enthusiasts who mostly don't know how to do a 2-stroke rebuild. The oil pumps were added by clever Yamaha & Honda engineers for one reason: increased engine life & reliability. The difference in reliability was so huge that most "premix" bikes like Bultaco & Montesa went out of business after Yamaha (and Honda) introduced oil injection. If you figure you know more than Honda, Yamaha, Suzuki, Hirth, Rotax, BRP, and the aircraft engine builders that insist on oil pumps for reliable engine operation, there's not a lot the rest of us can do to save you from self-destruction. As has been said before, you must have more "dollars than sense".
You trying to teach me about 2 stroke technology changes is like a 2 year old trying to teach grandpa. I lived thru, so shut up and just admit you are wrong. :jack:
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Re: Stock Oil Pump Delivery Ratio

Post by JJ Joseph »

Bear45-70 wrote:You trying to teach me about 2 stroke technology changes is like a 2 year old trying to teach grandpa.
There's no point. You're still a bit too young & belligerent. Not ready to learn anything useful. Now where's that nice snapshot that I had stashed away . . . Oh, here it is again:
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