Flush Muffs...

[mikew4]

Cant get my flush muffs to work. Attach, switch water on, turn engine on, and no water comes out the tell tail. Scared to leave the engine running for too long....

Engine works fine in the sea, with plenty of water pressure out of the tell tale. Its a new Merc 150.


Cant work out why. Muffs are covering the intakes at bottom of engine. Half decent water flow. I'd expect some to get sucked through. Weird. Could it be that its a self priming pump and the water pressure is not enough, resulting in too much air?

Thoughts & suggestions?

[Xk59D]

Buy double hose muffs Trem Outboard Flushing Muff Attachment - Double Feed - Outboard Flushing Attachments - Discount Marine Chandlery and Sailing Equipment. Bargain Boat Spares and Clothing or run it in a barrel.

My outboard won't run on hose either, I do get water but it isn't enough so overheat alarm follows.

[mikew4]

I have double muffs! No joy. Suspecting its water pressure.

[Festinghouse]

its funny my force 120 wont pump from muffs, but my old mariner 75 would pump well even just spinning on the starter motor - same gearbox / water pump etc!

[Nos4r2]

Does water come out of the centre of the prop?

[Dirk Diggler]

Originally Posted by mikew4

Its a new Merc 150.

Which model?

Some mercs don't pee till the stats open.

[uncle al]

I used to have that problem with the V6s especially if the water pressure was down,if I was unduly worried I dropped them into one the test tanks.I had that luxury.

[phantom 19]

Most big outboards won't flush properly on flush muffs, even if you have a telltale - out of curiosity I removed the block anodes of a Yamaha f150 recently running on flush muffs and water was only just trickling up to the lowest point and wouldn't fill the block up at all.

The best way to flush a large outboard if you don't have a test tank is to obtain a large pvc prop trailer bag and tie it securely around the leg above the gearbox with the drawstring. Make sure the engine is fully down and the prop bag resting on the ground for support. Fill it up with water and leave the hose in it and keep the hose running while th engine is running - you will properly flush the engine this way and will achieve full water flow / pressure. Obviously keep an eye on water level but did this on a Yamaha 300hp recently for a good 15mins and was fine.