470 carb help

[bolo789]

hi guys, i need a little help here please. 470 merc 2 barrel carb just got it rebuilt, i think it run for a little while. problem start when we run out of fuel and i mess with them two ajusting screws on the side. now every time i try to start it dont stay running, if it do stay running as soon as i start to give it gas it just BACKFIRE AND DIES. when i do get it to run i have to let it sit for a long while in nutral, then it will run. it will run good for the day if i dont turn it of the moment i turn it off it start the same thing again. help please.<br /><br />the porgys are here and i dont want to miss out lol<br />bolo

 

[bolo789]

Re: 470 carb help

i also change the filters

 

[Trent]

Re: 470 carb help

Idle mixture screws are to be adjusted when the engine is warmed up. Pleliminary setting is 1.25 turns CCW from full in. Backfire is a lean condition. Try an loosen the three retaining screws on the choke cover housing and adjust and retry. Normal choke setting is such that scribed mark on cover is in line with long case mark on choke housing.

 

[akriverrat]

Re: 470 carb help

since this seems to have started after running out of gas check filters for water/crud. can also cause lean condition. may also have water/crud in carb bowl/s.

 

[bolo789]

Re: 470 carb help

thanks guys for the quick respond, i had fogot to to post that when i did got back the carb from the shop, that choke ajuster, i did move it to a diffrent setting, it was not ajust the same as the other one so i shift it to the same as the other. i also did not wait till engine reach the propper temp when i made the ajust. thanks for all the info. i will give it a try tommoro.<br /><br />bolo

 

[bolo789]

Re: 470 carb help

hey guys i just came back from the boat yard and i did what you all suggest me to try play with the choke and ajust the two screws as describe. it is running a little better but i think it has a fuel restriction some where. when i put in nutral and rev it sound like it hesitate then it hold the rev the other engine does not do that. the thing is when it get warm up and w o t trottle it is fine but as soon as i switch the keys of it hard to start and backfire. what are the problem does a fuel pump give when they are going bad????<br /><br />thanks for all the info

 

[bolo789]

Re: 470 carb help

almost fogot, when i turn of the light to the engine compartment, and rev the engine i notice lot of sparks in the altinator. my ?? is it sopose to do that?? one engine has the original charging system. the one with the sparks is the one with the convert altnator. help.<br /><br />thanks again

 

[horndog]

Re: 470 carb help

the alternator problem sounds like someone slapped in an automotive alternator, which is why you can see sparking. The marine alternators are sealed. <br /><br />As far as the carb problem, it maybe the accelerator pump not adjusted right or maybe worn or broken<br /><br />What carb is this and what year is the motor?

 

[bolo789]

Re: 470 carb help

thanks i dont know what make is the carb i will find out when i go back to the boat, about the altnator it is real scarey imagine in the dark when you rev the engin all you see in the alt is fire spark you wont see it in the light only in the dark. i will shurely change it soon. <br /><br />thanks again. also where is the execelerater pump ????? is it diffrent from the fuel pump??/ fogive my spelling.

 

[Brzwrking]

Re: 470 carb help

New board for 470's<br /> http://www.breezeworks.net/cgi-bin/MBoard/forum/