backfire 1800 sr 4.3 v6

[chucknorristoo]

recently bought 1800sr 2002 has v6 4.3 double carbs ,
when engine runs it backfires intermittently but runs smoothly if you gradually open the throttle with the linkage disconected. any ideas boat buddys tell me that the timing is out.

[Gazjen]

Could be timing, mine back fired well with the timing out

Could also be bad fuel, Bad plugs dirty carb etc has the boat been laid up for a while?

[seapuppy]

welcome to the zoo...from what your describiing...sounds like the carbs are out of synch.....get one of those carb sync kits or one of the venturi type used on webber carbs ....then learn where to adjust the carbs....once sync'd up...then you can address the timing/plugs/plug wires/distributor cap and rotor...and points if you have them....but I'd start with the carb's themselves....also make sure that the mounting bolts are tight...no vacuum leak at the base.....do this before you try working on the carbs....use soapy water and a squirt bottle...shoot it around the base..if the engine smooths out...you have a leak...if not....move on....


SP irate:

[chucknorristoo]

Originally Posted by Gazjen

Could be timing, mine back fired well with the timing out

Could also be bad fuel, Bad plugs dirty carb etc has the boat been laid up for a while?

thanks for that will start with timing then work my way through carb

[chucknorristoo]

Originally Posted by seapuppy

welcome to the zoo...from what your describiing...sounds like the carbs are out of synch.....get one of those carb sync kits or one of the venturi type used on webber carbs ....then learn where to adjust the carbs....once sync'd up...then you can address the timing/plugs/plug wires/distributor cap and rotor...and points if you have them....but I'd start with the carb's themselves....also make sure that the mounting bolts are tight...no vacuum leak at the base.....do this before you try working on the carbs....use soapy water and a squirt bottle...shoot it around the base..if the engine smooths out...you have a leak...if not....move on....


SP irate:

thanks for that, will set timing then work through carb.