[Beller]

My trans. oil is going over to the engine oil side on my "04 CRF240R. I have gathered from other posts that the right side crankshaft seal is the problem. I have just changed that seal and after about an hour of riding the same thing is happening again. Anyone have any suggestions?? Long time reader--First time poster!!

[Beller]

OOOOOPPPSSSS!!!!!!!! CRF250R

[Asmith]

Besides the crankshaft seal there is also a balance shaft seal that goes in the left crankcase. It must be that seal as well.

[Beller]

Thanks Smith. I will replace that and post results.

[n.i.mxer]

How much oil is transferring across out of interest and over what period of time? As ~ says, there only 2 seals that can be the problem.

[Beller]

About half of my trans. oil is tranferring over in aprox. 1 hour. When I pull the engine oil dipstick the oil runs out on the ground. I have it apart now and picked up the balance shaft seal at the dealer today. I think I will go back together with it tonight but will not get out to ride it for a few days. We picked this bike up used about 2 months ago and the guy we bought it from had just had the engine rebuilt. Aftermarket crank, stainless valves, '06 cyl., etc... The right side crank seal looked to be new when I changed it a couple weeks ago and what I can see of the left side seal (without removing the flywheel) I think it is new as well. However, the countershaft seal I took out seemed to be harder and had no sealing compound on the outside of the seal as did the crank seals. I am hoping that the last guy just did not replace the countershaft seal and a new one will fix it. Does anyone know if there is any other place where oil can transfer from side to side?

[Black z400]

Looks like I'm having the same problem on my 06. I just noticed my engine oil being way way overfilled last ride after sitting a month, but my clutch has been going out, and the basket and hub are toast. My bike has been running great though, so I think I'm lucky the bottom end isn't destroyed. When I drained the oil, the transmission was dangerously low. I have yet to replace either seal, but while I'm in there, I figure I may as well replace both. Is there anything else to remove to access the balance shaft seal, while replacing the right crankshaft seal? Also, are any special tools or solutions required to replace the seals, or do I just push them in?

Thanks

[nimxer]

Looks like I'm having the same problem on my 06. I just noticed my engine oil being way way overfilled last ride after sitting a month, but my clutch has been going out, and the basket and hub are toast. My bike has been running great though, so I think I'm lucky the bottom end isn't destroyed. When I drained the oil, the transmission was dangerously low. I have yet to replace either seal, but while I'm in there, I figure I may as well replace both. Is there anything else to remove to access the balance shaft seal, while replacing the right crankshaft seal? Also, are any special tools or solutions required to replace the seals, or do I just push them in?
The new seals should puch in with you thumbs. Getting them out, thats a different story. You can get seal pullers which are useful.
Thanks

well the balance shaft seal is on the opposite side (LHS) of the engine to the clutch. So unfortunately you will have to remove the ignition side cover as well as the clutch side casing. The right side crank seal and the counterbalance seal should cure you're oil transfer problems. you will need to remove 2 gears from the clutch end of the balancer shaft to allow it to slide out the other side to access the seal. A small piece of alluminium or soft metal between the gear teeth will do for jamming the gear on the end of the crank and the gear on the balance shaft allowing you to undo the balance shaft gear nut. Hope this makes sense While you are buying you're seals, also get 2 new gaskets for both crankcase covers as they WILL rip.
The new seals should push in with you thumbs. Getting them out, thats a different story. You can get seal pullers which are useful. Make sure you fit the RHS crank seal to the specified depth. It's in the manual

[Black z400]

Thanks for the suggestions, and I understand what you mean with jamming something behind the gear. I believe a penny will work, correct? It seems more often the case that it is the right crank seal leaking, and I think I will go with replacing just that and see what happens from there. How much is a seal puller, and if I don't get one, how else do i go about removing it? Is it necessary to put any kind of sealing solution on the seal while pushing it in, or just press it right in? Still waiting on the manual until I can do anything...

Thanks.

[n.i.mxer]

Thanks for the suggestions, and I understand what you mean with jamming something behind the gear. I believe a penny will work, correct? It seems more often the case that it is the right crank seal leaking, and I think I will go with replacing just that and see what happens from there. How much is a seal puller, and if I don't get one, how else do i go about removing it? Is it necessary to put any kind of sealing solution on the seal while pushing it in, or just press it right in? Still waiting on the manual until I can do anything...

Thanks.

Well if the left crank seal was leaking you wouldn't know. both sides of the left hand seal are surounded by engine oil. Makes you wonder why they need a seal there! Whereas the right side seal separates transmission oil from the engine oil around the crank. (2 compartments of different oil). When the right side seal blows, the tranny oil fills into the engine compartment, hence the engine oil level goes up and the tranny level goes down. I can't say why, but it's usually this way (tranny to engine, and not engine to tranny) Sounds confusing but think about it.
You don't need any sealing compound. A small electrical screwdriver MIGHT work to get the seal out.
Good luck with the fix.

[Beller]

So i now have replaced both the right crnk. seal and the balance shaft seal and the problem persists...ran it for FIVE minutes tonight-warmed it up then up and down the street and my wonderful engine lovingly transferred 230cc of oil to the crankcase side for me!! i installed the crank seal like the Honda service manual shows and the balance shaft seal is installed with the numbers out-spring facing the right side(clutch side) oil...could this be backwards?! Anybody have any ideas for other places to look for this much oil transferring in that short of time? And i checked the breather hose and they are definitely clear!! Thanks-this is getting a wee bit frustrating!! Thanks for all the input so far!!

[Ray]

I have not had the problem, but these are possibilities from what I have read.

1. Right crank seal. Use th '06 seal it is improved.
2. Balancer shaft seal.
3. Left crank seal.
4. Sprocket seal.

Let us know what the fix is. This topic needs a sticky.

[Beller]

Ray-isn't the left side crank seal just keeping the resivor(left cover) oil away from the crank oil? And the sprocket seal you're referring to is the seal just behind the front sprocket-is that the one called the countershaft seal?
Thanks!

[Beller]

Also i did use the '06 R crnk seal-the problem didn't go away-so now i have a new '04 R seal in there-just to get back to square one!! And that didn't change nything!! When a case is cracked do you transfer that much oil that quick? There are no obvious signs that i could see of it being cracked!

[Ray]

I haven't looked into this problem, these are just some possible solutions I have read in other posts and forums. Its possible No. 2 and No. 4 are the same. This problem has been addressed in ThumperTalk forums many times. You might want to give that a try if you don't have any luck here. Sorry I can't be more help.