Plugged oil pump. How is crankcase lubricated?

[Bugaboo]

Plugged my oil pump hole last fall and now interested in how the crankcase gets lubricated?

[eliteguy50]

Plugged my oil pump hole last fall and now interested in how the crankcase gets lubricated?

Hopefully you are premixing your oil and fuel. That is how it would get lubrication. The intake charge is sucked into the crankcase and then up to the cylinder.

[Wheelman-111]

Greetings:

Whether the oil is stirred into the fuel at the tank or sucked into the intake stream at the pump outlet in the manifold, it's The Miracle of Micro-Droplets that causes some of the oil to fall out of the atomized air/fuel mixture and deposit itself on every surface inside the cases.

Look closely at the crankcase and you'll see a pair of flywheel-scraping overhangs cast into the design. Just behind those, there are a couple of holes that lie over the main bearings. As the oil accumulates and pools there, the holes are intended to guide a trickle of oil over the main bearings. Random sloshing ensures that the lower cylinder/piston interface is lubed, carried up by the rings to the upper reaches of the cylinder. Everything else apparently depends on dumb luck. It's a miracle that the connecting rods even survive...

Early 4-stroke engines used to rely on a similar total-loss oiling system. The first Harley-Davidson singles ("Silent Gray Fellow" is the only name sillier than the "Eve Smile" if you axt me...) had a - Yikes! - Manual plunger that the rider was expected to operate periodically. I guess you waited until you heard a "clanking" sound to be reminded...

Before the EPA and concern for Cleanliness and Social Correctness arose, increasing horsepower, RPM and heat production required a re-thinking of the oiling systems in the new-fangled Internal Combustion engines. High pressure pumps and cast-in channels to every critical interface were the result.

[JJ Joseph]

Plugged my oil pump hole last fall and now interested in how the crankcase gets lubricated?

Most hi-performance techs (for instance, ultralight aircraft) don't recommend removing the oil pump without a lot of careful thought. The Honda oil pump is a superb piece of modern engineering that will prevent your engine from running out of lube in downhill/closed throttle ops. The oil pump continues to lube the engine, even when fuel flow is minimum. Removing the oil pump puts your expensive Honda engine into the same engineering category as an old lawnmower. The Honda Dio/Elite oil pump is engineered to oil up to a 125cc engine, so don't discard it without thinking about what you're throwing away.

[Wheelman-111]

Greetings:

Quoth JJoseph:

The Honda Dio/Elite oil pump is engineered to oil up to a 125cc engine, ...

I'm pretty sure (without checking) that the Aero/Elite 50 pumps aren't the same part as the Aero 125's.
Even if they are the same basic pump, the 50cc units are Calibrated to feed a 50, not the 72-85ccs that result from a BBK. Keeping the pump alone when displacement increases by ~60 percent is risky. I used to advocate a pump in combination with dilute premix, and it worked on my more resilient builds. However the strategy failed catastrophically - twice - on my higher-output engines. User Beware.

[richdavison34]

I still say the travel size mouthwash bottle idea is genius.

The Honda oil pump is a superb piece of modern engineering that will prevent your engine from running out of lube in downhill/closed throttle ops. The oil pump continues to lube the engine, even when fuel flow is minimum

How much downhill would you have to do to create a lubrication issue?

[Petrock's 1984 Spree]

You only have a problem going down hill if you close the throttle and are premixing.

Closed throttle= loss of lubrication. Always keep the throttle cracked open a little when going down hill

[JJ Joseph]

Greetings:

Quoth JJoseph:

The Honda Dio/Elite oil pump is engineered to oil up to a 125cc engine, ...

I'm pretty sure (without checking) that the Aero/Elite 50 pumps aren't the same part as the Aero 125's.

You're right on that, but the Elite oil pump still puts out lots of oil, more than enough to oil a mild 80cc street setup. Maybe not enough for a 125cc 12,000rpm drag bike, bit plenty enough for a spirited 90cc street scoot. The 44mm Ruima stroker crank, for example, has drive gear for the stock oil pump. I've never seen a street setup seize with a stock Dio oil pump, and you'll never seize up while wind-milling at high rpm on closed throttle. That's when you're in real danger of seizing a 2-stroke. With premix, as soon as you close your throttle, you're oil supply drops to ZERO.

[richdavison34]

Post removed due to Noobness.

[Bear45-70]

..........................................The Honda Dio/Elite oil pump is engineered to oil up to a 125cc engine, so don't discard it without thinking about what you're throwing away.

If this statement were true then why do the Aero 80 and Aero 125, 2 stroke scooters each have their own oil pump only used by that engine? So your statement is false because Honda doesn't even believe it.

Aero 80 = PUMP ASSY., OIL 15100-GC8-722

Aero 125 = PUMP ASSY., OIL 15100-KG8-013

Actually the statement that your oil supply drops to zero when you close the throttle with premix is BS. The is lots of spare oil floating around in the crankcase, or every 2 stroke that ever lived would have blown up the first time the throttle was close after running at WOT. If you don't know what you are talking about, shut the * up.

[Bugaboo]

oh snap! I agree with Bear tho. In my mind it would have to be a long hill to vaporize all that oil.

[Bear45-70]

oh snap! I agree with Bear tho. In my mind it would have to be a long hill to vaporize all that oil.

But the oil pump at least puts some oil into the engine with the throttle closed and if it is wired open........................

[JJ Joseph]

If you don't know what you are talking about, shut the * up.

Honest, a remark like that is the sign of a real bonehead. When you run out of intelligent input, then you start telling us to "shut the * up". Maybe you're not such a bonehead, but you're sure starting to sound like one. Why not take tomorrow off and learn something:

http://www.rotaxservice.com/rotax_tips/ ... ection.htm

Mixing your own fuel is unbelievably retarded. It lowers the octane of the fuel, it reduces the viscosity of the lube, it over-oils at low speed, it starves at high speed, fuel-gas mix doesn't mix properly in the tank, if you make a mistake, you can't double-check the ratio, the engine starves for oil at part throttle, oil-pump engines last 4 times longer, and on and on. This is a tech forum and readers deserve an intelligent, knowledgeable response to questions, not just some backyard BS from a lawn-mower tech. Maybe you think you know more than the army of engineers who designed these engines, but I really doubt it. To us you're just some unemployed know-it-all in your mom's basement. Take a break. Read a book:

https://www.amazon.ca/High-Performance- ... 396&sr=8-1
https://www.amazon.ca/Basic-Design-Two- ... 396&sr=8-3
https://www.amazon.ca/Emissions-Two-Str ... 396&sr=8-7

[bakaracer]

If you noticed,its the same idea honda did for dummies that for get to put oil in the gas tank.plus on airplanes its very expensive to repair if you don't fly it all the time to have the premix gas sitting in the carb. Same as if you didn't ride your scoot for over a year. You have to clean the carb out same on a plane if you leave premix in there for a short time. The loosing 2 points on octane only aplys the av gas for planes not pump gas. If premixing wasn't as good as the oil injector,all the race teams that win championships would use the oil injector. But they don't.

[808BMW]

JJ loves his oil pump, and the rest of us don't.

I've personally never had any problems with premixing in over 7 years of riding modified mopeds. I have heat-seized a stock bore multiple times on the stock pump, zip-tying it wide open helped a bit, but not much.