Flushing OB

[Rebel112r]

Bought this for 50 bucks, now easy peasy to flush while on trailer.

 

[Bob&Jilly]

I see and why is this better than rabbit ears? With rabbit ears you are always pushing in fresh water with a bucket you are circulating the same dirty stuff- correct?

 

[venajeff]

The cooling system on the Yamaha 250 and 300 doesn't run correctly on the ear muffs. When I have used them on mine I don't get any water coming out of the telltale. So now I either just us a garden hose flush hookup (not running) or get a bucket. But it requires a large bucket. So this inflatable bucket is a very nice idea.

 

[Rebel112r]

I have used the rabbit ears(muffs) on other engines. They work OK. On the 300 it has secondary input, which can be covered with tape to flush.. with the muffs. Also needed new muffs, so I spent a few more bucks and went with the tub. The tub works great, folds up to nothing. And if I ever want to fill it with ice and water and hop in I can! That is what it was designed for.

 

[venajeff]

I never knew that was a thing until today. If I buy one of those I can assure you it will only be used to flush my outboard.

 

[Submariner]

The tub works great, folds up to nothing. And if I ever want to fill it with ice and water and hop in I can! That is what it was designed for.

It'd probably also work great for giving the dog(s) a bath. Just say'n... 😀

I use duct tape across the lower pickup, and heavy duty/big muffs for the upper intake, with a valve at the end of the hose to adjust the water pressure. It works good enough for me.

 

[Bob&Jilly]

The cooling system on the Yamaha 250 and 300 doesn't run correctly on the ear muffs. When I have used them on mine I don't get any water coming out of the telltale. So now I either just us a garden hose flush hookup (not running) or get a bucket. But it requires a large bucket. So this inflatable bucket is a very nice idea.

Makes sense, my understanding is that the garden hose alone does not flush the entire motor- correct?

 

[venajeff]

The manual only mentions cooling water flushing by means of the garden hose attachment on the side of the engine with the engine turned off. And as Martin showed there is a way to plug up the front intake vents and use earmuffs. That is probably good enough, but I am not certain of that. If you run it in a large bucket then you're definitely safe.

 

[Submariner]

The manual only mentions cooling water flushing by means of the garden hose attachment on the side of the engine with the engine turned off. And as Martin showed there is a way to plug up the front intake vents and use earmuffs. That is probably good enough, but I am not certain of that. If you run it in a large bucket then you're definitely safe.

It's really two separate issues. If I want to flush the salt water out of the engine, then the flushing port/hose connection is all I need, with the engine off. This is what's detailed in the service manual. If I put a big bucket under the motor and filled it with water, I am diluting the saltwater and recirculating it back into the engine. Is that a big deal? It would depend on how many gallons filled the big bucket. Probably not, but it's not a really a flush. It's also better to flush the engine of salt when it's hot, which is just when the boat's pulled from the water. The flushing hose is quick and easy to connect. I always put my hand under the tell-tale to make sure warm water is coming out.

The photo I posted above of me idling the engine on ear muffs I do this after I do the 100 hour engine maintenance to test and make sure the engine idles and circulates water before I launch the boat. I want to make sure water comes out the tell-tale, especially after replacing the water pump. I'm testing the engine while out of the water, not concerned with flushing the salt out.

Using duct tape on the lower inlet ports is tricky and is why I have to have a valve on the end of the hose. Full water pressure from the hose will blow the tape out. I start out with a little water pressure, start the motor, then open the valve and adjust as necessary until I see water coming out the tell-tale, but not enough to blow the tape out. The muffs I use are the HD/Large muffs also, designed for larger engines such as the F300. I always get water out the tell tale when on the ear muffs.

 

[venajeff]

Yeah, that is when I first found out about this issue, when I was running up the motor after replacing the impeller. I have always used earmuffs on outboards with no problem so it didn't occur to me that it wouldn't work. After not seeing the telltale I thought I installed something wrong. I actually re pulled the lower unit to double check everything. I didn't think of using tape, that would have been easier. I ended up using our yard waste bin. But cleaning it out and getting it in place was not fun. I am actually a little surprised no one makes a earmuff specifically for these outboards, we can't be the only ones inconvenienced by this.

 

[Fantic]

Had the same problem years ago with a Mercruiser Bravo 1. The aftermarket does make a "cup" that goes over the front of the drive that has a rubber strap that goes to the back of the drive. Just use standard muffs. Maybe one of those would work.

 

[venajeff]

It'd probably also work great for giving the dog(s) a bath. Just say'n... 😀

I use duct tape across the lower pickup, and heavy duty/big muffs for the upper intake, with a valve at the end of the hose to adjust the water pressure. It works good enough for me.

View attachment 25129

I needed to run up the engine at home yesterday and I tried your tape method. I used some aluminum foil duct tape and it worked perfectly. Normal flow through the telltale the whole time. So much easier than the bucket method. Thank you!