Carburetor to lean??????

[twn827]

Hello I have a question and am hoping to get some answers. i have a 1992 volvopenta 431 which is burning spark plugs. after talking to someone they said the carburetor could be running to lean and causing the plugs to overheat. Anyone have any thoughts or ideas?

 

[ChrisCraftJohnny]

Re: Carburetor to lean??????

Have you inspected a spark plug yet? If it's very very white, you are running lean.

Also a lean condition will produce sputtering a high RPM's and possibly some detonation.

Johnny

 

[twn827]

Re: Carburetor to lean??????

thanks. it does sputter and backfire at wot. it also seems like it is missing at wot.

 

[Alpheus]

Re: Carburetor to lean??????

Then it is most definitely running to lean. Check your fuel filters and fuel pressure. I would suggest you STOP running it in this condition. You run a very high risk of causing severe engine damage...

 

[John_S]

Re: Carburetor to lean??????

Hello I have a question and am hoping to get some answers. i have a 1992 volvopenta 431 which is burning spark plugs. after talking to someone they said the carburetor could be running to lean and causing the plugs to overheat. Anyone have any thoughts or ideas?

If you have signs of burning/melting sparkplugs, the same is happening to your pistons. As others have stated, it is most likely a lean carb condition. Once that has been found and fixed, check your base timing and advance.

 

[bigdan1]

Re: Carburetor to lean??????

hope for you it`s not too late already ...
had a cutomer that piston no 3 had a hole in midlle by running too lean .

too lean = very high combustion chamber temps

 

[twn827]

Re: Carburetor to lean??????

thanks for the info. i already stopped running it and did not go to far since the new carb was installed. i already had the carb adjusted and new plugs in. also put a new fuel filter on also. anything else?

 

[Aloysius]

Re: Carburetor to lean??????

Too advanced timing will cause a similar problem. remember, ethanol laced fuel causes a lean condition in a carbureted engine, since the ethanol is an oxydizer!

 

[twn827]

Re: Carburetor to lean??????

thanks for the info. had the carburetor adjusted and took it out for a 45 minute run. there was no backfiring or missing at all. no sounds from the engine so i do not think it burnt any pistons. HOWEVER: after running it we docked to get the trailer. once we docked the engine would not start up. it tried to turn over and then just a clicking sound. any ideas as to if this is the starter or perhaps just the solenoid??

 

[Alpheus]

Re: Carburetor to lean??????

thanks for the info. had the carburetor adjusted and took it out for a 45 minute run. there was no backfiring or missing at all. no sounds from the engine so i do not think it burnt any pistons. HOWEVER: after running it we docked to get the trailer. once we docked the engine would not start up. it tried to turn over and then just a clicking sound. any ideas as to if this is the starter or perhaps just the solenoid??

Start another thread or do a search...

 

[6meter]

Re: Carburetor to lean??????

Just a little FYI, lean running carbs cannot be fixed from outside the carb.

 

[Danny Mc]

Re: Carburetor to lean??????

If you have a new carb it may have the wrong jets in it.
As 6meter says you can't adjust rich or lean cond from out side the carb.

 

[a70eliminator]

Re: Carburetor to lean??????

He said the carb was adjusted and now it runs good, so however they adjusted it must have worked.

 

[bruceb58]

Re: Carburetor to lean??????

ethanol laced fuel causes a lean condition in a carbureted engine, since the ethanol is an oxydizer!

has nothing to do with being an oxidizer and has everything to do with a different stoichiometry but at ethanol less than 10% its not a critical difference to even worry about.