omc flappers?

[marlinempress]

I have an '86 omc 800 that I was inspecting the other day. Lo and behold when I look at where the exhaust comes through the intermediate housing there was something jammed in there. I took it out and it looked like some kinda piece of metal covered in rubber but the rubber was pretty deteriorated. I really don't know what it was, maybe a flapper or something... I've also been having problems when I turn off the motor in the water, when I turn it back on it idles fine but bogs badly when I accelerate until I rev it repeatedly to clear out the engine or something. Any thoughts on if those two things are interconnected? <br /><br />Thanks,<br />Matt

 

[cobra 3.0]

Re: omc flappers?

Yes, it's a flapper. It may have been related, but not necessarily. It could be anything...a carb needing cleaning, timing off, gas filter clogged, choke needing adjusting, etc.

 

[marlinempress]

Re: omc flappers?

I must mention that the engine doesn't do that as long as I'm not in water, on the muffs it runs perfectly when I shut it off and turn it back on. Is this flapper essential to the operation of the boat? What exactly does it do? It's got a throttle body fuel injection on it so no carb. The timing is right on. I've leaned out the choke adjustment on the ECU as far as it goes just to see if that was it, same thing. Thanks for the suggestions, keep 'em comin'!

 

[rybad]

Re: omc flappers?

The flapper prevents water from back flowing into the exhause manifolds. When your in the water, and shut down the engine, you probably have water back flowing into your engine, causing it to run ruff until it blows out.<br /><br />The flappers usually cost about $40-$50 a pair, and are easy to replace. Just pull off your exhause hoses inside your engine compartment, and they are located just inside the Y pipe on each side.<br /><br />-Dave

 

[marlinempress]

Re: omc flappers?

thanks a bunch for the information. I've looked everywhere and can't find replacements for it though. Anybody know where I could find some?

 

[rybad]

Re: omc flappers?

www.ebasicpower.com, or www.marinepartsfinder.com<br /><br />I just ordered new ones myself this spring. I think they were around $20 each. Be sure to get new bushings and pins too (if they have the kit, I think it includes all the parts).<br /><br />Very important: Be sure what year your engine is.. don't go by the year manf. of your boat. OMC changed these a few times, some flappers are about 1/2" difference in size.<br /><br />-Dave