Something I don't get about 2 strokes......

[99LRDblaster]

.......why don't they put a dedicated lubrication system on 2 stroke powerplants? I personally don't see why their can't be a 4 stroke type sump lubrication system on a 2 stroke engine.......and it's been done before, so WTF? :-/ Really, I would say the single thing that kills 2 strokes in reliability over 4 strokes is WOT scenarios where riders then let off the gas and the throttle slide closes......end result?......the engine is still turning RPMs as it falls, but is getting vastly less fuel.......AND vastly less oil. Not to mention situations such as engine braking and downshifting with the slide closed....sucks balls for the engine because it is getting less oil than it truly needs and the end result is quicker wear. This case is solved with a 4 stroke sump system that lubricates the engine nonstop.......so why not just implement it on a 2 stroke....is there any reasoning behind them never getting around to doing it?.....it surely can't be cost. :-/

 

[bonesZ33]

its a good logic, i can't think of a reason that they woudln't put it in other than cost myself, there is no benifit of not having an oil system.

 

[blasterdude14]

They do have a direct injection system for 2 strokes, its only available on snowmobiles though I believe. Pretty sure thats basically what your talking about. Direct injection can pretty much allow a a 100:1 ratio for fuel

 

[99LRDblaster]

They do have a direct injection system for 2 strokes, its only available on snowmobiles though I believe. Pretty sure thats basically what your talking about. Direct injection can pretty much allow a a 100:1 ratio for fuel

I don't see how it would matter. Now I realize there are some obvious setbacks to running a TRADITIONAL 4 stroke system in having the crankcase volume used for intake charge for a 2 stroke which isn't the case in the 4 stroke, however there are oil slots that lubricate the engine at other points(wristpin) to accomplish this task, so why you couldn't do the same with a 2 stroke but add a a separate sump for the oil outside of the crank and have a have an oil return location possibly at the bottom of the crankcase.

 

[UncagedShadow]

On a side note 2 stroke diesel engines have a dedicated lubrication system. It allows for vastly increased efficiency and vastly decreased emissions, the main enemy of 2 stroke world. The main reasons are weight and size and cost. The battle with the quad and dirtbikes has always been power vs. weight, and cost effectiveness vs. consumer demand. Most of these diesel 2 strokes are stationary equipment that have no need for a compact design. The 2 stroke diesels that were used in big rigs by detroit diesel also where in a large truck where size was not a problem and power torque wasnt either since this was a diesel engine.

 

[Paulie B]

I'd say cost and the added complexity of the system. Yes it would be easy in my eyes to have oil ports cast into the jug for the oiling but it would have to be rpm depended.
This would require some kind of sensoring, a computer of some sorts, an oil pump, and battery.

 

[4cfed]

or dow aht i do when coming from wot to idle... i chop the throttle as i slow down... ill crack it wide open and 'burp' the throttle to give it bursts of fresh fuel as i come off wot problem solved

 

[bonesZ33]

or dow aht i do when coming from wot to idle... i chop the throttle as i slow down... ill crack it wide open and 'burp' the throttle to give it bursts of fresh fuel as i come off wot problem solved

IF your not too busy slamming on the brakes haha

 

[NEONNIGHT34609]

i have a 95 seadoo jetski that uses the 2 stroke oil from the tank and runs it though the bearings.alot of people take the oil system out and dont realize that you have to loop a hose with a fill cap to make a closed loop oil system for there bearings. if you dont that that BAD sh*t happens

 

[xJust_Causex]

I love the old 2 stroke diesels. Biggest thing that killed them is like any 2 stroke is the fuel consumption. About the biggest problem with the system on the blaster is the plastic gear. But there at the same time you won't get lube to the top end off the throttle. If you go for a system that lubes the top end full time then you either have to recover that used oil some how or burn it off which is a problem when you are not on the throttle delivering fuel and air to the top endB if you just let that oil collect in the bottom then you have to separate the incoming fuel charge from the oil otherwise it will begin to contaminate that oil and it loses it lube capabilities

 

[roadkill]

IF your not too busy slamming on the brakes haha

ive made a habit of grabbing the clutch when i come down instead of engine braking

 

[99LRDblaster]

or dow aht i do when coming from wot to idle... i chop the throttle as i slow down... ill crack it wide open and 'burp' the throttle to give it bursts of fresh fuel as i come off wot problem solved

Yea I typically do that as well, plus I run the pilot rich as I am never below 1/4 throttle anyways, so when the slide is closed it at least gets a little help from the fatter pilot/screw through the cutaway.

 

[99LRDblaster]

I'd say cost and the added complexity of the system. Yes it would be easy in my eyes to have oil ports cast into the jug for the oiling but it would have to be rpm depended.
This would require some kind of sensoring, a computer of some sorts, an oil pump, and battery.

Not necessarily. You would think the same for a low tech 4 stroke like the 400ex, but that's not the case. Sure you have the crank in an oil bath, but the rest of the assembly is lubricated by other means.

 

[Zwiser]

is this why somtimes if your coming from WOT to off thottle the engine will pre detonate because of a lean condition?

 

[Zwiser]

another question can you actullay hear predetonation with the revs up, ok this is my situation, going down the dirt road WOT then let off the thottle to slow down and ping ping ping... blip the thottle and it goes away then let off again and same thing

 

[Deerslayer89]

Yeah i just pull the clutch and coast.

 

[99LRDblaster]

is this why somtimes if your coming from WOT to off thottle the engine will pre detonate because of a lean condition?

That's usually a sign of something a little more. Prolonged engine braking could cause it, but typically the slide being closed just causes a small amount of heat buildup due to leanness while revving down and causes excess wear, but it is something that doesn't typically show up right away and is just an example of 2 stroke engine life being cut down more as a whole, but that's a matter of years typically or however hard you ride and/or length you ride.

 

[99LRDblaster]

Yeah i just pull the clutch and coast.

As do I, but it still takes time for the engine to rev down.....the summation of all those periods over the course of a year or two takes their toll.

 

[99LRDblaster]

another question can you actullay hear predetonation with the revs up, ok this is my situation, going down the dirt road WOT then let off the thottle to slow down and ping ping ping... blip the thottle and it goes away then let off again and same thing

Predetonation can really occur anytime. If you generate excess heat then yes, you will have it occur. As was said earlier, you have to pull in the clutch otherwise you have an engine igniting and pulling the same RPMs it would be at 3/4 throttle for example....except it's not getting the fuel to cool the engine at 3/4 throttle nor the oil to lubricate it.

 

[Paulie B]

I believe the old tech 4 stroke use the oil bath technique for the entire motor similar to a 2 stroke tranny. The valves have seals on them to stop oil from coming into the cylinder.
The oil bath system would never work because it will be burnt during combustion. The age old problem with an oiling system on a smoker is that the compression happens on both the top and bottom of the piston.
It would be nice to have such a system because the friction of the piston traveling up and down the bore does take away alot greater percentage of the power output then a 4 stroke.