when do you run your blower motor?

[prairiethunder]

long story short my family burned down an i/o when I was 4 yrs old becasue a blower motor didn't turn on prior to the first start of the day. I know you should run them 4 min prior to starting. Do people leave them on continuosly during use? only at start up? or at slow speeds? A friend said he leaves it on any time the motor is running... would prefer to replace the bolwer more often than risk fire. (makes sense but sounds like overkill) what do most do?

[SkiTower]

At first start-up, I run the blower and open the engine hatch. After first start-up, I run it any time I'm not up to speed. I try to turn it off when I get up to speed but occasionally forget, though better to forget to turn it off than on.

[core-rider]

Pretty much what SkiTower said... I usually turn mine on while waiting for an open spot on the ramps, and keep it running till we get on plane. I will usually turn it on for extended time periods of idle speed driving, and I'll flip it on before starting the engine after the boat sits for a bit.

[8122pbrainard]

Never on my 54 and 64 because they never have had blowers. I just do the lift the doghouse and smell method. My 77 does have a blower and I will run it for a minute or so before starting. With all three boats, I've never encountered any fume build up underway at any speed. Of course without a gas leak, there shouldn't be any fumes!!

Checking what's going on under the doghouse each trip I feel is far more important than the blower.

BTW, any gas leak of considerable size won't be vented by any blower.

[AirTool]

BTW, any gas leak of considerable size won't be vented by any blower.

That's what I'm thinking....maybe good for sucking out some fumes left over after pumpimg up a big carb then killing the engine. Any leak from a pressurized fuel injection system is going to be more than the blower can exchange.

I think today's blower is there mainly to make the Fed's happy.

AirTool

[8122pbrainard]

BTW, any gas leak of considerable size won't be vented by any blower.

That's what I'm thinking....maybe good for sucking out some fumes left over after pumpimg up a big carb then killing the engine. Any leak from a pressurized fuel injection system is going to be more than the blower can exchange.

I think today's blower is there mainly to make the Fed's happy.

AirTool

I certainly agree! Hopefully the next step for the USCG will not be seat belts!!

[GoBig]

Technically, you are supposed to run it before start-up and anytime the engine is at idle (<1000 rpm). Frankly, I rarely ever use mine. I always pop my engine hatch while I'm prepping the boat for launch and leave it open until I fire it up. After that, like Tool said, anything in the engine compartment dangerous enough to start a fire likely will not be vented with the blower alone. It is better to pop the hatch and do a visual check prior to first start-up then it is to blindly run the blower.

[tadelfio]

I agree with Airtool however, I do turn my on when I think about it. But I don't sweat it if I forget.

[Teleman]

Silly thought....is the blower motor totally sealed? If not, and the mixture is right ...Ka-boom. Last I knew, the blower motor is a DC motor with Brushes and small sparks from those brushes. Weather it blew in or out it has to start in an environment of Kaboom-able mixture. If not the right mixture it is just there to make noise. So is this a problem or is it there just for the USCG.

[AuMDLST]

Not on purpose - but I rarely if ever turn on the blower - maybe 6 times before start in the last three years.

On a side note - not a direct reason why, while trailering the fumes, if any, should be gone as to the 50+ mph
travel.

[8122pbrainard]

Technically, you are supposed to run it before start-up and anytime the engine is at idle (<1000 rpm). Frankly, I rarely ever use mine. I always pop my engine hatch while I'm prepping the boat for launch and leave it open until I fire it up. After that, like Tool said, anything in the engine compartment dangerous enough to start a fire likely will not be vented with the blower alone. It is better to pop the hatch and do a visual check prior to first start-up then it is to blindly run the blower.

I wonder who's came up with the "Technically, you are supposed to run it before start-up and anytime the engine is at idle (<1000 rpm)". The manufacturers? The USCG? Maybe the insurance companies!!!

[saceone]

1000rpm idle? mine idles at 650.

[prairiethunder]

Thanks for all the advice. I agree the blower won't do much if there is a fuel leak etc. I was thinking the best would be to crack the motor cover when launching.

[harddock]

For what its worth. I open the engine hatch, press the ign and blower button, Start engine, make sure all is ok under hatch and go. When I shut off the boat, I shut off the blower. I don't notice it is on, it doesn't rob any power, or make any annoying noise. and I've yet to blow up. I'll keep using mine all the time.

[M3Fan]

I leave mine on all the time as well. Doesn't take away from anything and with my insulation kit I can't hear the blower running at all. I don't feel that it's a completely futile exercise- it does pump a lot of air out and gas fumes are heavier than air and will settle down in the bilge right where the blower is. The fuel/air mix has to be just right to make a really good explosion so I figure the blower is at least throwing off that fuel/air ratio at all times.

Edit: If nothing else I'd feel REALLY STUPID if the boat did blow up and I didn't have the blower on. Explaining that to the cops, fire department, insurance agency, newspaper, etc. would really make me feel like a dufus.