Use your blowers

[rkluck]

I always run them before I start the engines for the day. Once the day has started I usually don't run them again.

 

[Bruce]

Are these blowers are pushing air out or in? Or does one draw in and one out?

I've seen all 3 variations in boats but never looked at mine. I assume both are exhausting air to the outside.

On my SX230 they both extract air from the engine compartment. There are vent holes on the opposite side for fresh air to enter.

 

[txav8r]

How does a 2015 240/242 know when your going to start the engine? Does it prevent you from starting until the engine compartment is evacuated? I like the idea of the blower automatically turning off after a few minutes, but that isn't the critical safety issue, it is evacuating the compartment before starting. If I am in a hurry, I just open my hatch first and then start, rather than waiting 4 minutes for the blowers to do it.

 

[Glassman]

We're not talking about propane here, fuel vapors are lighter than air, so they will be apparent if you have fuel vapors in the engine compartment when you lift the hatch. Nonetheless, run the blowers before start. I like the idea that if your at sub plane speeds, that you run the blower, because it as @Shuck Water says, is not drawing air as effectively.

Mel, did you want to double check that post?
Air has a vapor density of 1. Substances with a vapor density greater than one are heavier than air and tend to accumulate in low places. Gasoline has a vapor density of 3 to 4.

That's why the bilge blower suction hose is placed at or just above the lowest point in the engine compartment/bilge. To suck out the gasoline vapor.

 

[txav8r]

Thank you for pointing that out @Glassman and you are correct. I intended to say "fuel vapors are lighter than propane" and didn't. I will leave what I wrote for continuity but hopefully anyone that reads it will see both yours and my replies to it. My point was it won't hide from the blowers suction nor would it hide from ventilating the compartment by opening it. But doing both is faster than waiting on the blowers alone. Clarity is a fleeting thing...lol

 

[Glassman]

Thank you for pointing that out @Glassman and you are correct. I intended to say "fuel vapors are lighter than propane" and didn't. I will leave what I wrote for continuity but hopefully anyone that reads it will see both yours and my replies to it. My point was it won't hide from the blowers suction nor would it hide from ventilating the compartment by opening it. But doing both is faster than waiting on the blowers alone. Clarity is a fleeting thing...lol

I knew you knew what I knew you knew.




But it got me to thinking...(a dangerous thing) I was thinking about the so-called "False Bilge" that at least my model year has...I don't know about the newer hull designs, the point I'm going for is, does fuel vapor sink into - can it sink into the area below the floor of the engine compartment?

That would be a not good thing. And I do always open the engine compartment prior to starting before launching...never know what lurks in there after being stored. Critters have been known to get into boats and nibble away at important stuff and I for sure don't want to find out about it when I turn the key....especially if the nibbler nibbled on a fuel line!

 

[Bruce]

@Glassman may have found the reason that Yamaha says to leave the drain plugs closed in the engine compartment floor. Having the drains open, as I do, would allow fumes to get into the bilge.

 

[Murf'n'surf]

Even with the plugs in the stinker can linger in the area under the clean out tray.

 

[MikeyL]

I knew you knew what I knew you knew.... ...

@Glassman .............. Did your English teacher approve that above ????????
LOL !

 

[Matt Phillips]

I usually forget and leave mine running as well.

Just remember: a cup of gasoline in the bilge of a boat is about equal in potency to a stick of dynamite.

 

[Julian]

Just remember: a cup of gasoline in the bilge of a boat is about equal in potency to a stick of dynamite

Which is why it is worth $200 to put in a device that tells you when you have dynamite (gas vapor) in your bilge!

 

[Glassman]

Which is why it is worth $200 to put in a device that tells you when you have dynamite (gas vapor) in your bilge!

There you go making me feel guilty. First it was the high water alarm. Now I gotta get a vapor detector.....jeesh. Wait, can I just pay a small child to ride in there and yell if there's a problem?

And thank you Bruce, I didn't think of that! Finally, the secret of the plugs has been revealed

 

[ArmyChief]

Reminder for all of y'all who proudly are able to own a 2015 24-foot Yamaha with CONNEXT:

You can SET your BLOWERS to Automatic.

Why is this ONLY in the 24's?...seems like they could have added that across all the lines.

 

[MikeyL]

Why is this ONLY in the 24's?...seems like they could have added that across all the lines.

Only the 2015 24-footers this year's new CONNEXT System.

 

[biglar155]

Couple things I'll comment on:

First, (on the 230 series anyway) yes it is possible for vapors in the engine compartment to get into the "lower bilge." First, there is the hole for the bilge pump. The pump sits on the floor of the lower bilge. There is a hole in the "pan" of the engine compartment that the pump sticks up through. There is also a half-dollar sized hole in the lower rear of the compartment that leads to the area under the clean-out tray. This is also the the lower bilge. Vapor can easily pass through either of these holes and accumulate.

Second, here's my pre-start routine: On the first start of the day before starting blowers (still on the trailer), I open the engine compartment, get down on my hands and knees, and use one of the best, most sensitive chemical detection devices on earth to check for fuel vapor. I have to get down on my hands and knees because the device is rather inconveniently (and permanently) stored just above my mouth. If I were to ever smell even a hint of fuel vapor (I'm talking raw gas here, not that normal engine-compartment smell) then the show would be off for the day.

Next I close the compartment and turn on the blowers. By the time I've finished prepping for launch and we are backed into the water it's been 4 minutes plus. I open the compartment, sniff again, start both engines, and sniff one last time - plus visually inspect for anything happening that shouldn't be. This really doesn't take but a few seconds and you're not going to notice a new fuel leak if you haven't started the engines because the lines won't be pressurized - so always check once after starting. (My uncle once found fuel spraying across his exhaust manifold from a broken fuel line that way. This was actually in his truck, but the principle applies.)

Blowers stay on at low speed mostly because I forget to turn them off. I DO like to run them at low speed but I think with two 4-cylinder air-pumps moving air under there the danger is pretty low if I don't turn them on. Still, better safe...

For on-water restarts I usually just run the blowers for 5 min or so and then fire it up. (But I'll confess that usually at some point while everyone is splashing around in the water if I can get the engine compartment open w/o having to move too much stuff around, I'll stick my nose in there just for kicks.)

A vapor detector IS on my list, but I think it's better to check yourself than to rely on a vapor detector. Instruments fail all the time in my line of work. If you lean on them too heavily you can get an unpleasant surprise.

That said, it doesn't HURT to have the instrument. You just need to make sure you don't abdicate all of your responsibility to it.

 

[Julian]

What exactly does the automatic blower function do?

 

[Julian]

That said, it doesn't HURT to have the instrument. You just need to make sure you don't abdicate all of your responsibility to it.

Couldn't agree more! Other than drowning...blowing up your boat is probably the 2nd or 3rd most dangerous part of boating....

 

[Julian]

There you go making me feel guilty. First it was the high water alarm. Now I gotta get a vapor detector.....jeesh. Wait, can I just pay a small child to ride in there and yell if there's a problem?

And thank you Bruce, I didn't think of that! Finally, the secret of the plugs has been revealed

Sorry Glassman.....thats the problem with this site....too many ideas for ways to spend more money on our toys!!!

 

[Evil Sports]

I never remember to use the blower, barely used it on my 4winns for 10 years

 

[MNdrifter]

According to this article, most blowers are not rated for continuous use. They should only be run for short periods of time and then shut off.
http://www.boatus.com/boatTECH/articles/bilge-blowers.asp