1988 Yamaha 200 ETXG outboard oil leak in cowling

[Bullet1750]

Just found this from Rodbolt

if that is the original kien oil pump on the engine then it will have 6 nipples pointed straight up.
most likly one of the check valves below the nipples failed.
if one does then not oinly will gravity drain the engine tank into the intake it will allow that cyl to NOT get oil when running.
crankcase pulses will be transmitted to the oil line.
if the valve failed you can dissasemble the pump and remove all 6 and replace them with the mikuni pump style inline check valves or buy the mikuni pump replacement kit.
the kien pump and parts are and have been NLA for a long long time.
on the oil control module, the original design can and will turn the the transfer pump on if the battery hits about 9 v or lower.
it will then stay on and empty the remote tank.
replacement designs since about 2000 have rewired internal circuitry.
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[Tucker]

Sounds like the oil is draining past the oil pump into the carbs, then into the silencer, then into the cowl. It's worked fine for 25 years, it's allowed to break now

[rwwillhunt]

1988 Yamaha 200 ETXG outboard oil leak in cowling

I still run two 1986 115,s (although not much with price of gas) on my boat. I have had the oil leaking problem on both of them over the years. Both times the problem was resolved by replacing the oil pumps. Apparently the check valves go bad in the original pumps. Since replacing the pumps I have not had any oil leaks on either of them.

[Tucker]

Bullet the check valves that rodbolt is refering to keep oil from going back to the pump. Your oil is going the other way towards the carbs.

[Bullet1750]

Bullet the check valves that rodbolt is refering to keep oil from going back to the pump. Your oil is going the other way towards the carbs.

The header tank is higher than the leaking injector so gravity does the work. I Pulled the top off the oil pump and out of the six oil ports one had oil backfeeding past the spring loaded check valve. It was obvious which one it was. Using a lenght of stainless TIG wire I depressed the check valve a heap of times and pretty much straight away it sealed. Only then by pressing in in slighly would the oil flow back, there must have been the smallest piece of crap just holding it open. I have filled the header tank and will check in 24hrs if if have gone down at all. Heres hoping.

[Bullet1750]

24hrs and oil tank still full........It was going down about an Inch each day........All good

[99yam40]

May be a good idea to drain, flush, and clean tank and lines including check valves every few years like Yamaha recommends.
You can test and flush out check vales with a syringe rigged up to hook up to line.

Do not forget to bleed oil system well before running it after

[johnaspro]

Blue oil leaking at cowling

Hello gentlemen john here new to the forum. I have had the same leak which I recently located was coming out of the oil pump where it is bolted to the block. There is a seal on the back of the oil pump that does not seem to be a replaceable seal, that was leaking out a considerable amount of fresh oil running down the cowling to the bottom small cowling and down the mid section. Also the resovoir was showing the level going down from the gravity effect. Then consider that the line or lines bleeding down will cause air in the lines and starvation to the upper cylinders. This couold cause an engine cylinder to fail ruining a good engine?? I was lucky I found mine before an issue came about. Mako Joe you know what I mean now???