Yamaha 2 Stroke Oil Injection Pump

[SlayerT123]

Hi All,

Just wanted to make sense of the Oil flow for 2 stroke outboards. On my 40 HP I noticed the Oil tank has a extra hose that appears to feed back into the oil tank. Can someone please confirm the flow.

1) Does the oil flow into the pump from #39, which then gets pumped into the 3 hoses ( # 9-11) which are attached to the inlet manifold?
2) Is hose #35 & 32, return hoses which feed back into the tank?
3) Whats the purpose of # 22? Is it just for pressure?

The reason I'm asking is because I recently decided to install new hoses that lead into the Oil injection pump. In order to replace them I disconnected the tank and all hoses. Then refilled the tank and started the engine. I noticed that hose #22 doesn't completely fill with oil, and I'm concerned that the oil is not being pumped into the feed in lines.

Do I need to bleed all the oil lines, and if so, is there a easy way to do this, as it appears that the lines connected to the intake manifold look quite fiddly to get to. Does the Carby's need to be taken off to connect/disconnect hoses #45 so I can check that oil is being pumped through?

Any advice is appreciated.

Thanks,
Tom

[Jason2tpa]

Reply back with the engine's year and model number

[SlayerT123]

Hi Jason,

the he Year is a 97, 40 veto (I think the equivalent is 40 tlrv)

[rodbolt17]

it is a self bleeding system.
what oil the engine does not receive is routed back to the tank. been that way on Yamaha tiny mites for 30+ years.

[SlayerT123]

Thanks Rodbolt for the update