CRSpeedy

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Nov 24, 2002
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Does any one elses CRF250 use oil. I fill it to the top mark on the dip stick and it goes down. After 1 moto it was halfway down so I left it to see if it just doesnt like to be filled to the top mark. but after the 2nd moto it's down to the bottom mark. It smokes when its cold but I dont notice it after it's warmed up.
 

High Lord Gomer

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Sep 26, 1999
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It has a dipstick?

The CRF450s I've messed with "appear" to have a high oil level (on the engine side) for a while after you shut them off. It has to do with the oil being pushed out of the crank well by pressure through a one-way valve. It takles a while for the level in the crank well and the flywheel area to equalize.

Both my 03 and my son's 04 used oil when new and even smoke a little when first started cold.
 

CRSpeedy

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Nov 24, 2002
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Hi Gomer, yes the 250 has a dip stick , unlike the 450. I feel better now that I heard yours used a little oil and smoked when cold. I also have a new yz250 and it does'nt smoke , even cold and has'nt used any oil. I'm thinkin about running it on the low side of the stick to see if it's just using oil cause it thinks it's over full. If an engine was over full that would cause it to smoke would'nt it? The problem is that it only holds 3/4 of a quart so there's not much flexibility there
 

Malden

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Feb 28, 2000
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The tech at the dealer where i bought mine instructed me to watch the oil level closely the first few hours. Said something like "honda told us to tell customers to watch it because it will consume a lot during break in"

btw, What oil are you guys running?? synthetic??
 

Rich Rohrich

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Most four-stroke engines are designed with a piston that carries two compression rings and an oil ring package (two thin rings seperated by a spacer) . The second compression ring on these pistons really serves more as an oil scraper than a compression ring. This second rind scrapes oil off the cylinder wall which helps prevent it from slipping by the top compression ring and burning in the combustion chamber. It's a common trend for ultra high speed engines to use only a single compression ring and the oil ring package in an effort to reduce friction losses and to allow the piston to be as short and light as possible to permit the high speeds these engines can safely run at. The CRF engine is designed with this current engineering thinking and only uses a single compression ring. When the engine is cold it is difficult for the single compression ring to stop all the oil. This situation is at it's worst when the engine is new, but it will always do it to some degree even when the engine is broken in. Single compression ring four-strokes always tend to use more oil then their dual ring competitors. Using a little bit of oil in exchange for performance is a good trade off in the long run for most of us.
 

CRSpeedy

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Nov 24, 2002
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Rich, that makes sense and it helps me to not worry about it but my son and I also have a new YZ250f and it never smokes, hot or cold. Ive been using honda 10w40 and yamaha 20w40 mineral but will switch to synthetic or semi soon. The Honda has about 7 hrs. and the Yamaha maybe 5 hrs on it. The dealer told me it was better to break it in with mineral oil
 

Rich Rohrich

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The Yamaha uses the conventional two compression ring design. All my YZF engines smoke a lot less than my CRF450. No getting around it. :)

There is some logic to breaking the engine in with mineral based oils. I always recommend that with a new engine for the first hour or so, in most cases beyond those first few hours it's OK to switch to synthetic if you want.
 

CRSpeedy

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Nov 24, 2002
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Thanx Rich , you sound like you are pretty familiar with these engines. I'm going synthetic on the next oil change. I change the oil every race week . What is your opinion on using Valvoline or Castrol 10w40 or 20w 50 synthetic from the auto parts store. It's alot cheaper, the oil is in there such a short time and the book just says not to use the "energy conserving" oil 5w30or10w30. Also what do you think about the 15w40 oils commonly used in diesels?
 

Rich Rohrich

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Originally posted by CRSpeedy
Thanx Rich , you sound like you are pretty familiar with these engines. I'm going synthetic on the next oil change. I change the oil every race week . What is your opinion on using Valvoline or Castrol 10w40 or 20w 50 synthetic from the auto parts store.
I've never used Castrol or Valvoline synthetic so I can't be of any real help.


Originally posted by CRSpeedy

Also what do you think about the 15w40 oils commonly used in diesels?
I've used Mobil Delvac 1 synthetic diesel oil with great results in a number engines.

Here's a link with some additional info on the subject. http://www.ericgorr.com/techarticles/mototech_june_1999.htm
 
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roostu

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Mar 18, 2003
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I have about 15 hours (havent rode in 15 years....slow) on my 04 CRF 450. It smokes on start up but thats about it. It gets less and less every time. I think I will probably stick with convetional oil due to the fact I change it just about every ride.
 

Rich Rohrich

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MX955 said:
I have a 2004 CRF250 with 14.6 hours on it,(there is a hour meter on it)and mine seems to be going through about 1/4 of a quart every 3 hours.Does this seem excessive.

Nope, that's about right. Depending on the oil and the number of hours on the engine it will tend to be in the neighborhood of about 1ounce per hour on the CRF450s. So far the feedback I have gotten is the 250s use a simialr amount once they are broken in.
 
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Rich Rohrich

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Regardless of what your friend THINKS, they all use oil for the reasons explained at the begining of this thread.
 

MX955

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May 31, 2002
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Rich Rohrich said:
Regardless of what your friend THINKS, they all use oil for the reasons explained at the begining of this thread.

We rode together last weekend at a indoor arena practice,I checked the oil in both bikes at the start and his stayed the same all night(about 2 hours).My oil level dropped on the dip stick.

I guess I will just have to keep a close eye on mine...
 

Rich Rohrich

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Riding style, ring sealing, engine temp and type of oil all enter into the consumption equation. Your bike is likely fine, but it's wise to make frequent oil checks a part of your regular track maintenance just like lubing the chain.
 

MX955

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May 31, 2002
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I checked again last night at our local indoor track to see how much oil mine was using now.It seems to be getting worse.In a hour of running time(by my hour meter)it used 150cc's or about 5 ounces.The bike only has 24.6 hours on it,this doesn't seem right.I will be calling my Honda dealer again tomorrow to see what they can do....
 

Rich Rohrich

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MX955 said:
The bike only has 24.6 hours on it,this doesn't seem right.I will be calling my Honda dealer again tomorrow to see what they can do....

He's going to tell you it's time to change the rings, and he will be right. He'll remind you that you've already gone nearly double the recommended service interval.
All single compression ring four stroke pistons use oil even when they are fresh , and they all wear faster the rings faster than the 2 compression ring types.

You might want to write this next part down :

This is NOT AN XR250, so you'd better get used to following Honda's recommended service intervals.

Below is a link to what can happen when you ignore those service intervals. We get a couple of engines like this every week and it happens to all the brands. Food for thought.

http://dirtrider.net/forums3/showthread.php?t=93889
 

Danman

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Does the CRF250X have this single ring design? So an 1 oz per hour is normal and how would that sit for a 4 hour ride (like say an enduro)? Would that put you relay low on oil buy the finish? What is the re-ring intervel. Is it a job that say the average mortal mechaincly apt person is capible of doing?

Is there any options for an aftermarket additional oil tank that would allow you to ride longer without filling up?
 

TexKDX

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Rich - have you had any clutch slippage issues with the Diesel oil in your bikes? I tried Shell Rotella T in two bikes (70s Yamahas) and both slipped the clutch. Switching back to a non-diesel 10w40 made the problem go away.

Is it possible the issue was the temp of the oil, in that the 2 strokes don't heat the oil up as well as the 4 strokes? Both yamahas were vintage trials bikes, so I definately was not generating much heat. Thanks, Leo.
 

Rich Rohrich

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TexKDX said:
Rich - have you had any clutch slippage issues with the Diesel oil in your bikes?


Research has shown that clutch slippage in wet clutch motorcycles is most often caused by varnish buildup on the clutch plates, as well as the normal deposits that come from long term use. Varnish is usually a byproduct of the breakdown of lower grade oils. Switching to a higher grade oil on a worn clutch usually seems to lead to slippage problems.

Changing the clutch usually solves it for good.

I started working with synthetic oils in about 1979 when I built my first air-cooled turbo charged dragbike. This bike saw massive clutch abuse and oil temps that cooked mineral oils, and cam bearings along with it. I started experimenting with Mobil Delvac diesel synthetic oil, in an effort to extend engine and clutch life. Clutch life on the bike was about the same but the engine didn't eat parts anymore. I actually got a chance to wear parts out for a change. :yeehaw:

I've had similar experiences with other projects I was involved in, so I can't say I've ever seen any evidence that diesel specific grades would cause slippage problems.
 

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