Advice needed for installing left crankshaft oil seal

[PcolaBeach]

Have a 1992 Elite SA50. This forum has been very helpful in troubleshooting and getting me to this point. Found the left side crankcase oil seal completely out of the housing by 1/8" and likely explains why it shut down 10 miles from home. Short of purchasing the tool(s) to press on a new crankcase oil seal, I'm wondering if anyone has come up with a clever tool to press on a new oil seal. As an example, 3/4" schedule 40 PVC pipe looks to be close in ID and OD dimensions to work as a drift over the crankshaft. Any other ideas would be appreciated. Thank you.

[Meloshameless]

That shud work, i used a metal pipe for mine

[PcolaBeach]

Thank you. I believe the ID of 3/4" schedule 40 pipe is ~ 15mm. Does anyone know the crankshaft OD for the shoulder area the oil seal rides at?

[bonesv]

Try to tap it in gently, squarely and only to about a 2mm depth else you could be pushing it into the oil pump gear area.
That's what I use is pvc pipe, cut squarely at both ends, using a tubing cutter.
Did you check the oil seal on the other side?
I wonder what caused that???
Welcome aboard!

[PcolaBeach]

Thanks. It's pretty dry on the alternator side. Evidently the previous owners had loaded the variator with a lot of grease. I believe the gunk in the photo is largely from being slung off of the variator. I don't believe there has been very much inspection or maintenance given to this scooter previously.

[vintagegarage]

Had this happen to me with two different Sprees and one SB50.. different engines, but same result. I use a piece of PVC pipe to set the new seals in place. The workshop manual for your engine indicates that bonesv is correct.. 2mm depth. I don't know what causes the seal to blow out, but it did happen to me in the SB50 while I was driving it at about WOT. So far, I have never had a new seal blow out. The two sprees came to me with their left seals blown out.. The first one was tough to diagnose. The previous owner said he was just running down the highway with it, when it stopped and wouldn't restart. The second was easy to diagnose.. the dead giveaway is no vacuum at the nipple on the intake manifold that supplies vacuum to make the fuel valve open.

[PcolaBeach]

Appreciate it VG. It was your post viewtopic.php?f=3&t=31793&hilit=low+vac ... case+seals that helped lead me to the crankcase area inspection. Also hit home that you'd rather be working on scooters than crossword puzzles. This users group has been a tremendous help in diagnosing why it wouldn't start. It's hard to see in the photo but the oil seal "s found" was about 1/8" away from the crankcase.

[vintagegarage]

PcolaBeach.. Thanks for the kind words.. the forum has been a big help to me too..

[PcolaBeach]

Just wanted to close out this post with an update that might be helpful to another. The OD on 3/4" PVC is slightly larger than the 25.7 mm OD of the crankcase / crankshaft oil seals.

IMG_1262 (1).jpg (70.18 KiB) Viewed 7658 times

So I added a pair of vice grips to one end of the PVC pipe for weight, held the pipe vertically and while rotating the PVC, put the heat gun to it until the PVC softened. Pulled on the PVC slightly to stretch it and create a taper then rolled it out on the workbench as it cooled. Marked the spot on the taper where the OD was 24mm, cut and whala.

IMG_1263 (1).jpg (67.73 KiB) Viewed 7658 times

The scooter is running well and I do intend to remove the flywheel, remove the right side oil seal and replace as well as it is likely of the same age or older than the left side. Other items replaced on this 1992 Elite SA50 include ... Carburetor overhaul, new air filter & spark plug, new piston rings, head & cylinder gaskets, new reed valves & intake manifold gaskets, new left side crankcase oil seal, new fuel petcock valve, fuel filter, fuel & vacuum lines and variator overhaul. About $160 in parts and 3106 miles. Thanks again all!

Frame-26-08-2016-09-24-12 (1).jpg (117.5 KiB) Viewed 7658 times

[Wheelman-111]

Greetings:

Check the crankshaft for runout and the bearings for play. Sometimes seals just fail, but often there's a reason.

[MrJumps]

Wheelman always brings the helpfull info in that no one thinks of. I agree with wheelman, if the old seal shows funky wear compared to the new one it would be exactly what you wanna do but if the previous owner has rebuilt the bike or the seals are brittle it could of poped out just from sitting for a while then being ridden hard or if the previous owner only put them in till they where fluch with the hole and not the correct depth.

[Wheelman-111]

Greetings:

The heat-stretching PVC idea was Brilliant. Wish I had thought of it first.

Worn bearings can introduce crank wobble, which is hard on the seals.

[PcolaBeach]

Thanks for the input guys. The old seal that was replaced actually looked pretty good other than riding outside of the housing and on the shaft. Bearings felt fine. Runout check is a good idea. Thanks!