RD250 right crank seal replacement question

[oldguyRD1964]

Hi, I have to replace the right side crack seal, wondering if this is possible without splitting the cases, I saw a few videos and they did this without splitting but they were not RD videos.

Never done an engine spit before so I'm hoping for the easiest method of course. Also, if I have to split the cases do I need to replace all the seals if they were done about 7 years ago.

Lastly, do you have any advice if I have to split the cases I have plastic bags to mark each part.

Thanks very much for any replies and comments in advance!

[m in sc]

you should def split the cases. rd oil seals have a lip/ridge in them along the center of the seal OD that locates in the cases. not all 2 strokes have that locating lip.

[oldguyRD1964]

Ok thanks, the search engine didn't work but scrolling multiple pages I see this topic has been discussed a bit.

I'm not sure about something I read called a labyrinth seal in the middle is this something RD's have?

[Jspooner]

RD crank seals have a ridge around them to keep them in place. You might be able to dig the old ones out but you'll never get the new ones in without removing the ridge. So the proper way is to split the cases to replace them. If you really don't want to split the cases you could go with DS7/R5 seals as they don't have the ridge and can be installed without splitting the cases. As far as replacing the other seals, the short answer would be no you don't need to, but I would just because they're cheap and why not since you are already there anyway.

[m in sc]

labyrinth seal is a mechanical seal in the middle of the crank, does not need to be replaced unless of severe mechanical crank failure. 

[oldguyRD1964]

Really appreciate the comments, every time I've had to replace/repair something on this bike it's been an interesting adventure, difficult but somehow I've done it.

The engine is the most complicated part to me obviously, I'm going to give it a try this weekend, I read experienced people do it in 3-4 hours I hope I can do it in 2 days.

[oldguyRD1964]

Hi one more question,
I'm looking at an RZ engine removal guide and wondering if I would need to remove the transmission it seems  there is only one seal on the end that is small to be replaced but not sure. Can anyone tell me about how many seals there are to replace? I know I bought a kit but I don't have it in front of me.

Thanks again....

[m in sc]

left and right crank seal. lh&rh
output shaft at sprocket (lh)
shift shaft.(lh)
clutch push rod seal (lh)

if you are feeling squirrely, trans shaft plugs, but id leave them alone. 

in the RH cover: oil pump shaft & kick lever shaft.
LH cover: none

sofe note:
WHEN you split the cases, take the whole clutch basket out and take off the bearing retaining plate behind it, it will hole the 2 cases together. 3 cross head countersunk screws hold it in.  you can't miss it when you get the clutch out. 

[oldguyRD1964]

Cannot thank you enough!!!

I'm trying not to stress out about it... but damn it's a big deal to me...
I keep forgetting I bought a dyna kit from Nick and he thinks I"m the biggest piece of sh*t and I lost the instructions to it.... I hope I don't need the instructions found something on his site so I hope it will be enough..

[m in sc]

why would he think that? don't worry about the dyna, there are a few of us familiar with the kit install. super easy. 

[Jspooner]

I actually have a few copies of his directions and would be happy to send a copy to you if you want or need one.

[m in sc]

Joe, you have a digital version? we can put it in the tech library

[SoCal250]

I have the RD400 version in PDF

EDIT: Now posted here http://www.2strokeworld.net/forum/index.php?topic=62.msg12964#msg12964

[oldguyRD1964]

Ok thanks on the dyna stuff... I don't even want to start something with that guy... long story short I ordered a kit he didn't ship for 4-5 days I cancelled the order he got pissed about it. Called me names etc...

[Jspooner]

Joe, you have a digital version? we can put it in the tech library

I just have hard copies but could make a PDF.