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Dry Sump?

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All DRZ's are wet clutch,, and all DRZ's are dry sump.. The two things are not mutually exclusive. Dry sump in the DRZ's case means ,,just that the oil is scavenged from the case sump and stored in the frame oil tank.

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I'm still not sure what the difference is between a wet sump and a dry sump? My question on this stems from my concern for maintanance of these to bikes. If I were to buy a E model and dual sport it would it require more oil changes than the S model as it is? Some of you know I just sold my Wr400 due to the fact that it could not be used as a commuter. One reason that was the case was keeping it maintained would have been a nightmare, changing the oil every 200 miles.... I know these DRZ can go 2000 miles per oil change from what I've read on this forum but I still don't quite understand how that is as the engines are pretty close to that of a WR. All I can see is that the S is dry sump lube and the E is wet sump lube, but what difference does that make?

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I'm still not sure what the difference is between a wet sump and a dry sump? My question on this stems from my concern for maintanance of these to bikes. If I were to buy a E model and dual sport it would it require more oil changes than the S model as it is? Some of you know I just sold my Wr400 due to the fact that it could not be used as a commuter. One reason that was the case was keeping it maintained would have been a nightmare, changing the oil every 200 miles.... I know these DRZ can go 2000 miles per oil change from what I've read on this forum but I still don't quite understand how that is as the engines are pretty close to that of a WR. All I can see is that the S is dry sump lube and the E is wet sump lube, but what difference does that make?

Umm, no,,, your not understanding... THEY ARE THE SAME,, all three bikes, S, E and Kicker are all the same,, wet clutch, DRY sump.

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Dry sump means the oil is scavanged from the bottom of the crankcase and stored somewhere else. In our case, the frame like late model BSA's and other bikes. In most apps, the oil remains in the bottom of the engine which is simpler, but also means a deeper crankcase which then poses bike clearance problems.

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All DRZ400's are dry sump. All hold 2 quarts. Depending on usage and type of oil used, the oil should be changed from every race day to up to 2000 road miles. Most owners change more often than max intervals.

The WR Yamaha is no different. I do not know how much oil it holds and that will make some difference but in road use, it does not need 200 mile changes. I'd say you would be fine with 1000 miles changes. About what I would recommend for the DRZ in the same use. You are right, The motors are not that much different. Most of us change oil way more often than it needs to be changed but it is cheap insurance and there is no way (short of oil analysis) to know when it is "time".

What I'm trying to say here is don't get too hung up on change intervals. Oil needs to be changed for only 2 reasons: contamination and the oil wears out. Good synthetic lasts a long time. Contamination? it is hard to know. Develop a routine you are comfortable with and go with that.

I do not recommend it but I know a guy that always bough old cars and drove them till they died. He never changed oil or at best once a year. (commuted 100 miles a day) and they seemed to last about as long as everybody elses. I just can't do that to machinery but some do and get away with it. Motorcycles will not stand that kind of abuse but in road use a water cooled motorcycle does not need 200 mile oil changes.

(DRY, DRY, DRY. I meant dry, I really did

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I posted this a couple years ago when I first got my bike and saved it in my document section. Thought maybe a repost might be needed and help you understand what your looking for. Hope this helps.

Enjoy!!!!!

I never have seen anything posted on how a dry sump oil system works. I have one on my VW powered dune buggy and now that I got my service manual I was comparing notes. It is one of the reasons I chose my DRZ . I hope the following explanation makes sense.

Basically, the oil pump is two separate pumps that run of the same shaft. There is the scavenging pump and the engine oil pump. The scavenging pump is more powerful volume wise. It is always sucking up oil from the bottom of the tranny case whenever enough accumulates or is sloshed by the oil pickup tube. It has a screen to filter out the big stuff but really gets most of the abuse. Its only job is to move the oil up to the frame, which is the reservoir. Hence the name dry sump oil system. The engine and tranny are shared space.

Now that the oil is above the engines oil pump gravity can even help a little. From the frame reservoir the oil goes through another screen and then to the other side of the engine oil pump. From there it is pumped through the oil filter and distributed threw out the engine and transmission by little oil passages.

After it has performs its duty it flows back to the bottom of the case and starts all over again.

There are several advantages to this type of system. Some of which are:

1. Allowing the air to separate out of the oil while it is in the reservoir.

2. Less oil needed in the system.

3. Allows external oil cooler. We don't need it because it is water-cooled engine.

4. Complete oiling at any angle without sucking air.

5. More power because internal parts aren't thrashing into the oil like the piston & crank.

I am sure there is more but one of the reasons I posted this was that we all seem concerned about how much junk we see in the oil after draining it out. The gears and clutch take more abuse than the engine because it is right there. But most of the important engine points like the heads and crank and rod big end are constantly bathed in fresh filtered oil from the none scavenging side of the pump. It is constantly flowing out of the lubrication points therefore the dirty stuff you see in the oil isn't getting in most of the time.

Remember that on a cold start there is more oil pressure due to the viscosity of the oil and much of it is bypassed around the filter until it warms up and thins down. That is what the hole on the end of the stock filter cartridge with the little peace of tin covering it is. There is a spring under there, which makes the oil go through the filter media most of the time. When in bypass it goes past the media straight to the oil passages. That is why they say to let your engine warm up before you start thrashing it. Plus the fact, as the metal heats up and expands the tolerances are closer. According to the manual the hot oil pressure at 140 degrees F and 3,000 RPM should be between 5.7 and 19.9 PSI. Or for you metric folks 60 Degrees C should be between 40 KPA. And 140 KPA.

Anyone reading this that see's a mistake please correct me if I missed something or add to the facts. Can't wait for my next ride! Thanks Greg

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