Hello everyone. I'm trying to figure out how to source the upper seal for my oil pump. I already replaced the lower oil seal (OIL SEAL (J10) product number: 9310110090) and the gasket that goes between the pump and the engine case (GASKET, PUMP CASE (MCA)
product number: 3MT1311600 supersession: 1261311601). The upper seal is not listed on any of the parts fiche I see. The entire oil pump assembly is listed as (OIL PUMP ASSEMBLY product number: 1641310104) but I only need that upper seal. I took apart a spare pump I have and found it's a circular, rubber, donut-type seal similar to the lower pump oil seal (9310110090). Does anyone know the part number on this seal? Have a source for it? Know anything about it that could help me?

Thanks a lot!

Here is the parts list I have:

Small internal driveshaft seal: 93104-06108-00-00
Primer end seal: 93101-10090-00-00
Pump seal : 93104-14059-00-00

Gasket 137-13142-00 or 86A-13142-00

No guarantee these fit your pump! Good luck!

Thanks Mark! I'm looking around for those part numbers and I can't find them on a parts fiche. Are those part numbers for an L5TA pump? Is the L5TA pump the same as other 60s era yamalube oil pumps?

I spoke to the dealer and they can't find internal parts for the pump either. He suggested getting seal # 93101-10090-00 (the bottom pump seal) and flipping it over because he thinks it will be the same size.

Does anyone know how to order seals by size? Could I just pop this one out and measure it?

Thanks again!

Those are seal and gasket numbers that fit many pumps from the first YG1-K to 1980 at least. There may be some variations, DEET is the expert. I can't tell you if they fit the L5. Chances are good that they do.

Seals are measured by Housing ID, Shaft OD, and Thickness.

Also seals often have the sizes right on them.

Here's a link to an exploded pump parts list. In later years it seemed Yamaha didn't want people messing with them so they started selling assemblies. I'm guessing there may be Service Bulletins out there with parts listed but I don't know that I've seen them.

www.partzilla.com/catalog/yamaha/motorcycle/1965/yg1tk/oil-pump

Thanks again for the information Mark! The pats list you shared does share the same lower seal (part #30) as the oil pump for the L5TA. The pump body is not the same part number, however. I wonder what changed there? My spare oil pump is from a YG1. They do look a little different but seem like they would match up in all important ways. In that YG1 parts diagram, the seal I'm looking for is number 19, part number 93104-14059-00. That seal is listed on eBay for $7. I guess for $7 I could just throw the dice. Wish I could get measurements off that seal.

Look in Tech Library. 69-71 AT/CT Parts list has an exploded pump view.

Part number for seal is 93104-14004 which supersedes to 93104-14059.

Old Yamaha Parts lists often give seal and bearing dimensions.



Seal dimension is 14mm x 25mm x 5mm