How to use Muffs

[Zerbel04]

Volvo 4.3 GL 2008. Bought some muffs to use for my boat as I would like to do some general maintenance out of water.

So I lowered my drive so it is relatively level and hooked up the muffs. They are the type that have a rod going through the water intake and clamp from opposite side. Clamped it up and turned on the water.

The only place water is coming out is from behind the muffs. I'm pretty sure they are on there tight. I've never used muffs or seen them used but it just didn't look right that water was pressuring outta the muffs. In any event I was not confident enough to fire my boat up and risk ruining an impeller.

Anyone with experience throwing muffs on a Volvo?

 

[QC]

Re: How to use Muffs

As long as the intakes are covered you're good to go. The reason that water is spraying out is because it isn't running and the pump is not pumping. The water is actually blocked by the pump until it is turning

Make sure you have plenty of flow (hose all the way on), and go for it. Best not to exceed 1500 RPM, 1000 even better. There may still be some bypass at the muffs. Don't freak about that; as long as you are pumping water out of the exhaust ports above your prop when running you are good.

 

[Don S]

Re: How to use Muffs

Do you have plenty of water pressure and volume? The pump has to suck the water up from the drive, so you need plenty of water and usually about 1000 rpm to get the pump primed.
Also make sure if you have a flush fitting on the engine that the cap is tight and not sucking air.
Could also be the impeller is about dead. Volvo recommends the impeller be replaced yearly.

 

[Zerbel04]

Re: How to use Muffs

Ok thanks guys. I'll give it another try tommorrow.

 

[skydiveD30571]

Re: How to use Muffs

The flush adapter Don is talking about is on the driver's side of your engine. It has a blue cap that can unscrew and a hose can be simply screwed into it. I originally bought muffs too but then realized I had this adapter and it seemed easier to use so I do. Obviously if you have an impeller problem this won't help anything, but if you plan on running on your driveway alot like I do, just screwing in a hose is a nice option.