Tuning 4.3LX

[blderman]

I just bought a 1992 Blue Water with a 4.3lx merc. It ran great but seemed to run a little rough so I changed the fuel filter, oil and spark plugs and cleaned out the carb. Now I can't get the engine to run for more than a minute or two before it dies. It definately runs much smoother than before when I do get it to run though. My first thought is that there is more fuel getting to the carb now and I need to re tune it. Does anyone know the stock settings of a the 4bbl carb that is on this model year?? Thanks ahead for the help. <br /><br />Jason

 

[akriverrat]

Re: Tuning 4.3LX

how did you clean carb? 1 1/2 turns out from gently seated seems to be the standard starting point for idle jets.

 

[blderman]

Re: Tuning 4.3LX

I used carb cleaner and rag, I took the boat out on the river yesterday and got her tuned in pretty good. My top speed seems a little low to me, not quite 40 mph, but maybe that is right for this size of boat. Thanks for the reply.<br /><br />Jason

 

[akriverrat]

Re: Tuning 4.3LX

read on another post to try this to check power valve: warm engine, wot, flame arrester removed, helper slowly closes choke. if rpms pick up with choke partly closed there is a problem with the power valve/enrichment circuit and time for rebuild.

 

[blderman]

Re: Tuning 4.3LX

I'll give that a try. Thanks for your help. I seriously hope that a rebuild isn't neccessary. I don't have the time or money for that right now.<br /><br />Jason