Crownline 202 BR backfires / pops through the carb, sometimes boat also smells of gas

[ibrw1]

Vent would be my first thought, bad float second

Right, vent clogged and carb issues, new plugs were dark after 40 gallons of gas. THANKS!!!!

 

[ibrw1]

Put fuel in your tank and you'll know if the vent is plugged, it will take forever and burp back up through the filler.You can also watch the mirage waves of fumes boil out of the vent while fueling.

So how do you like that K&N? I've seen them but the cost is crazy!

NEW PLUGS WERE DARK, CARB ISSUES, VENT CLOGGED.

ENJOYED VIDEO AND PICTURES OF SEA NYMPH...Hope to see more. Thanks for everything, Jim

 

[keith2k455]

So, how dark is dark on the plugs? Also, when you replaced them, did you replace with the same heat? I'd hate for you to chase a problem that doesn't exist. Can you post a pic of the plugs?

 

[ibrw1]

Ok, fuel smell problem is gone. Vent was clogged

BUT, the poping backfire through the carburetor still exists. I did a carburetor exchange with outfit in Florida
Where they claim that no adjustment is needed. Anyway, I installed it and I've noticed that it does run/idle better.

So 3 normal sized people in boat, RUNS GREAT, but after 15-20 minutes at 2800 rpm-3400. It backfires

You hear a pop, boat rpm drops significantly pushing everyone forward, then it takes off pushing us all backward.

I slow down for 5 minutes. And speed back up. Problem is gone. Takes 5-10 minutes at 3000 rpm
And problem comes back.

 

[ibrw1]

Ok, set special timing to 10 degrees before idle at 650. Went through everything, except the plugs! They are no longer the ones called out for by manufacture. They were crossed by little kid behind counter at local parts place. I'm changing back to original asap. This makes sense! Preignition when intake valve is open sucking in air/fuel mixture! It burps up into intake burning all the fuel for all cylinders! Then new supply comes in, boat takes off like bat out of hell! You are genius Keith. THANKS
Gas