RM250 Right Crank Seal Removal

[cannonballgsu]

Trying to get the cog off where the right crank seal is located on a 2000 RM250. Whats the easiest way to do this? And whats the easiest way to install the new seal? I don't have the tools the shops have, but I do have a manual. Any help is appreciated.

 

[rm250kenny]

use a pick to remove the old seal, and a socket of the same size and a mallet to install it. BE CAREFULL NOT TO PUSH IT BACK TO FAR!!!!!!!!!!!!!!!!

 

[cannonballgsu]

thanks, how do you get the cog off?

 

[ZOMBIE666]

if you dont have an inpact wrench you can wedge a shop towell in between the ring gear on the clutch and the crank shaft gear. this will lock the gears so you go to town with a ratchet.
hope this helps

 

[griffbones]

You may have to remove the clutch in order to get the primary gear completely slid off of the crankshaft.

 

[cannonballgsu]

Thanks again. I'm 99% sure its the main crank seal thats gone, but how can I be sure before I take it off, will it look damaged? I recently had the bike rebuilt and it was spitting oil like mad out of the exhaust and had little power up top. Im new to 2strokes so any help or insight is greatly appreciated.

 

[griffbones]

Spitting oil out the pipe is normally caused by rich jetting but a bad right side seal can cause this too. Symptom of a bad right side seal could also be a loss of transmission oil due to it being sucked into the top end.

 

[cannonballgsu]

I wouldn't imagine it would be jetting because it was fine before the seizure and rebuild. BTW, does anyoen know what size the nut is that holds on the clutch basket?

also, one revv will cover my hand in oil if i hold it behind the exhaust, i wouldn't expect that much oil is comming out of the gas

 

[76GMC1500]

I used an impact wrench to remove the clutch hub and crank gear nuts/bolts. I drove sheet metal screws into the seal and used a small pair of Channel Lock pliers on the heads of the screws to pry the seal out. My right side crank seal problem made itself apperent first by causing gouge to be worn in the piston over the exhaust bridge followed by frequent plug fouling (the plug appered clean but there was aluminum dust from the tranny that caused it to short circuit). The bike probably burned 100cc's of oil out of the transmission per day. There was no real difference in spooge before and after. If your engine locked up, check your crank breaings while everything is open. Grab on to the end of the crankshaft and try to jerk it up and down. There should be no movement. A little in and out is ok. Do this on the flywheel side as well. I replaced my crank seals only to have a crank bearing fail shortly afterwards. I basically wasted the $10 for the right side crank seal.

 

[cannonballgsu]

Thanks for the help so far, I got down to the seal and it is a tad bit crooked, but not much. It is maybe one or two MM furthur in on one side than the other, would this create a leak? I'm going to change it out anyway and reseat the new one flat.

 

[cannonballgsu]

AAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHHHHHHHDAL;SJFASO;DIL;KNGFASL;DHGASL;DIGF

My right case is cracked. I'm soo pissed. I now officially hate bikes. Anyone know where to get one of these without spending an arm and a leg?s

 

[Moparman1539]

Well.. if you can de-assemble the whole thing ang get the right part of the case off you can take it to a whelder and see what thay can do....

They can usally wheld anything up...

It would probebley cost $50 to get whelded... And thats alot cheaper than a new case

 

[76GMC1500]

You can just epoxy it.

 

[cannonballgsu]

I'm going to take it to a welder i know thats supposed to be one of the best. I'm just going to leave it in the bike and carry the whole thing to him

 

[2strokerfun]

Where is the crack??? How big is it??

 

[cannonballgsu]

More bad news, there is more than one crack, or it appears that way. The main crack is on the left

 

[Ol'89r]

Any good tig welder can repair that. Where are you located?

 

[sick 96 250]

Doesnt look to bad to me but I cant really see it to well with the red outline distracting me. Like mentioned a TIG welder can fix that up nice and quick if they know what their doing. If not use the auction site for some cases and have fun learning more than you wanted to tearing the motor apart. Not to hard once you get going.

I'm still a little concerned why it cracked there and its only a small crack and not a severe blowout.

 

[76GMC1500]

You might want to split your cases anyays to replace the main bearings. If they are worn, that would seem to me as the most likely cause of the cracking.

On another note, the casting process used by most manufactuers for cases leaves some spiderwebby ridges all over the inside of the casting that look exactly like cracks. I suggest getting the cases dye penetrant tested before doing any welding to see if the case really is cracked and the extent of the cracking. This is something you can do yourself if you can get the dye and developer.

 

[76GMC1500]

Search for Magnaflux Spotcheck. I saw a complete kit on FBay for $10.

 

[cannonballgsu]

I know there is the main crack, first picture to the left of the red line, sorry for all the lines, the welder wanted to knokow what he was up against. I did a leak down myself, pulled carb and exp chamber, plugged both holes and put a few lbs of pressure where the sparkplug was, worked like a charm.

The others may not be cracks, they just look like them.

I'm guessing the reason the case cracked is because the engine siezed at a high rpm and there could have been a huge jolt cracking it.

As for the bearings and internals, EVERYTHING is new from top to bottom, when we put the engine back in it was blowing tons of oil out the exhaust.

I'm sure the welder is going to do, he fabricates racing chassis for porsches and one that actually won the Lemans.

 

[sick 96 250]

whoever built the bike from bottom up should of caught the cracks I would think. Heck they may even of put them there using some stupid tactics trying to get the seals in or something else.

I've seen people break parts before trying to devise up a way to do something

 

[whenfoxforks-ruled]

There are casting marks like gm said. The likely culprit would be a hydraulic press for cracking cases,or a BFH!

 

[Bunya]

I'd lean towards improper install of the bearings also. Those bearings aren't a press fit in the case, they're an interference fit which is a couple thou tighter. I froze my bearings and oven heated my cases and they were still pretty tight going in. The cases are very thin to reduce weight and are easily cracked. Seizure at high speed would make the bearing spin, and even then the crank would normally spin in the bearing, not the bearing in the case due to the interference fit. In order to produce the crack(s), an outward force would have been required and I can't see any mode of bearing failure capable of producing the axial force required to break the casting.

 

[cannonballgsu]

Didn't want to wait, so JB Weld to the rescue. Cleaned with ether, sanded, cleaned with ether again and a wire brush and put the weld on. So far its holding fine and I don't think i'll have any problems. now just need to tune the carb, andyone got any pointers? Thanks for all the help!