Top tank overfilling

[Cchurcher]

Hi I have a Yamaha 2008 2 stroke 130 we have had some issues with the top tank overfilling and oil going down the overflow to be burnt in the engine.

Unfortunately this is an intermittent issue and the boat shop is having trouble tracking down the issue and wondered if this has been come access before.

The boat shop has replaced the sender in the top tank and the black control box that sits under the top tank (with the he pump switch on it) . The proble went away for a whole, about 6 months as it was winter and we didn't use the boat much.

After taking the boat out recently the boat went fine for a while whilst we were wakeboarding but then started smoking badly and dropping a cylinder when the plugs oiled up. On checking the top tank this was overflowing into the overflow.

I discussed this with the boat shop today and they said that the illy this it could be was the oil pump in the bottom tank not switching off. They lent me a spare tank which we fitted and took the boat for a run, and trying wakeboarding again as this seems to be when it happens most. The oil level remained perfect in the top tank during this test, about an hour.

We then changed the bottom tanks back to the original tank and repeated the test over another hour with issue.

So we are left with not really knowing what the issue is...

I am wondering if the issue is a broken wire due to the nature of the issue only happening sometimes. Sorry for the long explanation but this is frustrating and any help would be appreachated thank you, Chris

[rodbolt17]

its not the pump nor the remote tank.
once the oil control module gets the SW2 closed(pump on signal) and applies the ground on the blue pump wire the pump runs until it gets the SW1(pump off signal) to the oil control module and the module removes the ground path for the pump.
could be the blue wire is chafed and shorting to ground or a poor connection on the SW1-oil control wire.

could be the switch assy in the engine tank was installed incorrectly.

[boscoe99]

I agree exactly with rodnut. Either the blue wire to the pump is chaffed and being grounded or perhaps there is a switch/wiring issue such that the oil control module is not getting the signal to stop the oil pump from running.

If the sensor switch assembly in the engine mounted main oil tank has been replaced then I would first focus on checking the blue wire that runs from the oil pump to the emergency transfer switch/oil control module.

Do you have a multi-meter and know how to use it or are you relying on the shop to solve your problem?

[Cchurcher]

Thanks

Thanks for your helpful advice I have a son whom can assist with the electrics which is what I am thinking is the problem cheers