popping and backfiring upon acceleration

[jet3400]

Looking for some help, I have a 260cc single 454 we took it out for a run this past Tuesday night and upon acceleration the boat bogged down and started to pop thru the carb, the boat idles fine, low rpms is fine while at the dock I can throttle up and its smooth at 3000 rpm while sitting, but with people in the 3 0r more the boat bogs and pops and idea what could be causing this.. Thanks

 

[268 Frakenboat]

Looking for some help, I have a 260cc single 454 we took it out for a run this past Tuesday night and upon acceleration the boat bogged down and started to pop thru the carb, the boat idles fine, low rpms is fine while at the dock I can throttle up and its smooth at 3000 rpm while sitting, but with people in the 3 0r more the boat bogs and pops and idea what could be causing this.. Thanks

Check your fuel delivery. Check or replace filters. that should clear it up.

 

[scoflaw]

complete tune up is always step 1

 

[Quint4]

That is probably from a "lean" fuel condition. It can potentially damage your engine. You may need to rebuild your carb (or get a new one).

 

[northshore]

That is probably from a "lean" fuel condition. It can potentially damage your engine. You may need to rebuild your carb (or get a new one).

What he said.

I have an 89 with twin 454's that sounded wonderful at the dock (no load) but get out on the water, they would not accelerate cleanly and would occasional backfire out the exhaust. Rochester rebuild coming up if my guess is correct. It cured the same issue with my boat. The rebuild is not that hard to do if you dont have a problem with some meticulous work.

Hope this helps,

-Mike

BTW: Mikes carbs for the rebuild kit and National Carburetor if you want to buy a rebuilt carb

 

[sdarc]

check for vacuum leaks. With motor running, Fans on even an extra fan for some air movement spray some carb cleaner, WD 40, around and see if idle changes. If it does that should show the location of the leak.

If no leak is found then it could be carb rebuild time.