Yanmar YSB8 - Oil in Starter

[mait]

Bringing up this old topic.
I bought a replacement starter from ebay for my Yanmar YSE8G. It has slightly smaller body than original, but fits goods and starts engine fine. After running the engine for half an hour I found oil dripping from the starter body, from the back of starter where brushes are. Old starter was replaced because the brushes were worn. Now I remember that the brushes of an old starter were also soaked in oil and covered with brush-dust oil mix. But it didnt drip oil into bridge. Should the oil really get there? Maybe the new starter is not to meant to be installed to engines where oil can get into starter? I’m confused. Found no info from internet if oil should be there or not...

[Compass790]

I have a Yanmar ysm8, it has a lot of common parts with an SB8 including almost certainly the gearbox.
The starter gear goes onto the flywheel ring gear which dips in the transmission oil
DO NOT DRAIN YOUR TRANSMISSION OIL TO KEEP STARTER DRY!!!!!! Unless you want to destroy your gearbox. I can guarantee mark zarley is wrong.
Our 1980 ysm8 has been running all that time with the "nose" of the starter wet with oil with no problems as it's designed for that.
I use silicon or Loctite 518 flange sealant to seal the face of the starter when you bolt it back up.

[Compass790]

Originally Posted by mait

Bringing up this old topic.
I bought a replacement starter from ebay for my Yanmar YSE8G. It has slightly smaller body than original, but fits goods and starts engine fine. After running the engine for half an hour I found oil dripping from the starter body, from the back of starter where brushes are. Old starter was replaced because the brushes were worn. Now I remember that the brushes of an old starter were also soaked in oil and covered with brush-dust oil mix. But it didnt drip oil into bridge. Should the oil really get there? Maybe the new starter is not to meant to be installed to engines where oil can get into starter? I’m confused. Found no info from internet if oil should be there or not...

See my post #12, Your yse8 is very close to our ysm8. I'd suggest your replacement starter came from China & they didnt bother to make it oil proof like the yanmar original.
You'd be better off to take your old starter to a place that rebuilds them & tell them the pinion gear runs in oil.
I didn't actually pull our starter apart so I don't know how it's sealed from the oil but it must be to last 39 years.

[Wotname]

When in doubt - read the manual

Yes there is an oil seal in the Yanmar Y series starter motors - refer the screen shots.

Mait, I also suggest rebuilding your old stater motor, I'm sure it will be better than the new Chinese one. The parts will be common ones and should be available at any bearing shop except for the brushes which will be available at electrical motor shops.

[mait]

Thanks for replies! I will have the original starter reconditioned and then open the Chinese one to see whats in there. If there is a seal missing or is it not made to be working in oil.

[Compass790]

Originally Posted by mait

Thanks for replies! I will have the original starter reconditioned and then open the Chinese one to see whats in there. If there is a seal missing or is it not made to be working in oil.

Please post back what you find out when you look at your chinese starter.
I know of a marine diesel mechanic who refuses to buy the chinese starters but he's tied up with Yanmar so he isn't unbiased. Doesn't mean to say he doesn't have good reason to steer clear of them though.
Your experience says he's right.

[mait]

back to this old thread.

I opened the Chinese starter motor and found there is no oil seal. So this starter motor is not suitable for Yanmar YSE, YSB, YSM engines (although it is advertised to be suitable).

I also opened the original starter motor. There is an oil seal measuring 28x17.5x6 mm. The brushes for the original starter are 7x11x18mm.
Maybe it's helpful for someone else.

[Wotname]

Thanks for the update mait.