gear case and drive gear removal crank seal change mag side

[AdrenalineJunky]

So I spent quite a bit of time to try and find methods on here to pull the gear case off, and get that drive gear off the crank to change that inner crank seal on RH side. I hope it will be easier for the next guy with this thread.

To pull case; long bolts of threaded rod into the stator mount bolt holes and using a puller agains the crank end the case will come off its dowels and off the case. The bearing comes with it. No need to take apart water pump, tach drive, or oil pump.

Now, the crank end pump drive gear. From what I gather, and please correct me if I'm wrong, or have more info, please add. The best way is too heat it up, and pull it off with a bearing / gear puller. Install new seal, bake gear in oven and then install.....make sure you note how far gear is pressed onto shaft. I plan to use a micrometer and measure its distance from case before removal. I have to assume its right, but looks like its been pulled before.

Thanks for any add. info!

[AdrenalineJunky]

What a Bit#@! I had to cut the gear off. I don't have a torch but did use the hotter map gas for extended periods of heat on that gear and all it did was destroy two brand new puller set ups. Luckily I found a nos gear on ebay and proceeded to cut off wheel removal procedure.

Now, the seal, aftermarket, is fighting me. It just don't want to go in at even with some serious pressure. I ended up making a seal pusher tool which works off the threaded crank end and compresses the seal in. It looks like it just wont get past the first rib on the seal. wtf. I'm going to try to bevel the case a bit to allow for "wedge". Any other ideas? What a huge pia all this just to change some seals in a low mile good running motor.......that had little to no oil in the housing. I haven't even got to the water pump seal unavailable fiasco yet.

[opsled]

If you are trying to install new crank seals you need to split the cases to do in. The rib on the seal fits into a groove in the case. That groove helps with sealing and keeps the seal from coming out. If you are just trying to push or pound them in without splitting the cases all your wourk will be for naught and they will fail.

540's are a pain and seal availability is a problem. 81 SRX 440 is worse. Not an engine for the novice two stroke guy. Done right they will last a long time. Done wrong they will go down before you hit the end of the driveway.

Take your time and do it right. Get a service manual if possible. Big help.

opsled

[AdrenalineJunky]

Thanks opsled, that was my last resort. Will do. I've done many 2s motors, mostly not Yamaha, this is the first that needed case split to do. PIA. Yamabond on the way.

[AdrenalineJunky]

I guess its a good thing I got into the case. The mag bearing to a beating........all the others are excellent. Must have been run with bad water pump seal for a bit.

[AdrenalineJunky]

Finally had some time to work on it. Motor should be back together soon.

[mathis]

Good work.

[killerklown]

Just getting ready to pull my gear to change seals as well. Of course my puller isn't long enough...
What puller have you guys successfully used to pull that little SOB?

[AdrenalineJunky]

Just getting ready to pull my gear to change seals as well. Of course my puller isn't long enough...
What puller have you guys successfully used to pull that little SOB?

100's of them on ebay just a std bearing puller set. Look for a set that has a thin wall area that go behind the gear. My set was just tapered and did not work well. Your gonna need to get that gear real hot to pull it. At least that's how mine was, even then I couldn't get a grip on it and had to cut the gear off. good luck.

[killerklown]

Yeah, thats why I said SUCCESSFULLY...lol

[AdrenalineJunky]

Another fyi for those doing these, not sure if this has been discussed here or not but here it is again. The gasket set available these days ie winderosa do not include the mag side outer seal. This is the seal directly behind the stator plate. Winderosa # 501487 t is the one you need readily available for cheap.
Im sure the waterpump (2 on later model) ones can be had by size too. Mine looked new and did not leak so I didn't need to search it extensively. Mine said 25 44 11 on the outside seal. I'm thinking the 25 44 7 can be used, two with one or both cut down a bit....available at usa bearings and belts and others.

[Loosenuts]

Be careful with the heat on that gear......to much will cause the crank to expand also making it not want to come off. I heat it just enough that it will slip off without a puller.

[killerklown]

Finally got my gear pulled tonight. Of course the only puller I had here was too short, so I had to extend it. Wasn't as bad as I was planning, just took a little patience...