No spark arresters or baffles

[moneysucker]

I figured that this would be a good way ask boat cop a question. With a blower (carburated) do I have to run spark arresters? How about blown injected. I know it is nearly impossible to back fire through the carbs I just want to know what the law is.

[CrazyHippy]

I believe that you need them if you are in an enclosed engine compartment, or if the scoop is facing the passenger compartment.
Dont take this gosple however.
BJH

[mike37]

check this thread (http://www.***boat.com/forums/showth...threadid=43980)

[Boatcop]

The law says that a backfire flame arrestor must be attached to the carb of every gasoline powered engine (except outboards)
Now, you and I both know that the backfire originates in the intake manifold rather than the carb itself, and that a blower will prevent any backfire from exiting the intake or carb.
HOWEVER The law is what it is. It doesn't differentiate between intake systems. If you're found with no backfire flame arrestor on the carb, blower or not, a Lake Patrol with less technological knowledge than I will probably give you a ticket and kick you off the Lake, no matter how much you try to reason with him. Same with a judge, if you try to contest the ticket.
So, for the minimal air restriction a flame arrestor will cause, and their relative inexpensive cost, it would be better to install one (or 2 depending on the carb set-up), than to put up with the hassle.
They will also prevent foreign objects from getting sucked into the carb/blower. With the close tolerances of the blower lobes, almost anything inadvertantly sucked in will have you staring at several thousand dollars of scrap metal.

[moneysucker]

Thanks BC, I actually have the bug screen under my carb adapter to prevent stuff from entering the blower. I probably won't use spark arresters but with the scoop I run They will never know. I am a pretty obvious potential violation. Usually as soon as I produce all the necessary safety items and prove that I am sober it comes down to BSing about boats. Driving a drag boat with numbers on the side and a blower I have to be better than the normal boater because of the attention drawn. It has been good for me made me more responsible and careful on the water. It is a good thing you do here answering all our law questions even if it isn't the answer we want to hear. Thanks again.
Cy

[Boatcop]

I've actually raised the qustion about blowers with some of the legal types in boating law. Specifically about the relief valves. If one of these vent with fuel vapors present, it would have the same effect as an unrestrained backfire and explosion will result.
The only answer I get is a blank stare, and the bit abut "they're required on all carburators."
Sometimes trying to educate the lawmakers can be as difficult as trying to educate the boaters.

[BADBLOWN572]

Boatcop, does the flame arrestors have to be USCGA or what are the minimal requirements? I run a custom billet one that I had made with all S.S. Screen that I can guarantee you works just as good as any out there, but since I had it custom made, will I have a problem if stopped? I know that the carbs are Marine approved with J tubes versus straight vent tubes, but that I am sure won't make a difference if the cop is in a bad mood. Am I going to have a problem? But, like you said, flame arrestors are pointless on a blown boat. I just use them to keep bugs out of the air bleeds.