engine back fires at 3200 rpms

[blueagletalon]

i have a merc 470 four cyclender and i have the carb rebuilt. now it back fires at 3200 rpms. it it the carb or something else.

 

[havasuboatman]

Re: engine back fires at 3200 rpms

That would depend on whether of not it did this before the carb was re built.
If it did, probably not the carb, but another part of fuel delivery. Fuel pump, lines, etc. that are causing a lean fuel condition.
If it didn't, then yep, most likely a mis-adjusted carb.

 

[180shabah]

Re: engine back fires at 3200 rpms

Need more info.

Could be fuel, fuel pump, fuel filter, carb, fuel tank vent, timing, vacuum leak, etc.....

 

[blueagletalon]

Re: engine back fires at 3200 rpms

what more info do u need. it did not have the problem till the carb was rebuilt.

 

[a70eliminator]

Re: engine back fires at 3200 rpms

what more info do u need. it did not have the problem till the carb was rebuilt.

What problem did you have before the carb rebuild?
hope you didn't drop a nut down the hole.

 

[blueagletalon]

Re: engine back fires at 3200 rpms

we had a problem with it getting to much gas and fouling out the plugs.

 

[180shabah]

Re: engine back fires at 3200 rpms

What troubleshooting has been done to eliminate items listed above?