Over rich idle condition????

[Limited-Time]

96 LX Mercruiser sn 0F787870 This condition became evident after repowering with a remanufactured long block. Rich condition at idle, rich to the point of excess black smoke and evidence of unburned or partially burned fuel in the water. Vacuum gage reads 17" hg at idle Adjusting or removing idle mixture screws has no effect on RPM or vacuum readings. The rich condition clears at any thing above idle speed. Carb was just rebuilt to original specs. Performance otherwise is flawless. Seems to me to be a carb issue, other opinions????

 

[KaGee]

Re: Over rich idle condition????

Seems to be broke. <br /><br />(Snick) Sorry, couldn't help myself.

 

[Chris1956]

Re: Over rich idle condition????

Limited, If the idle mixture adjustment screws do not affect the idle mixture, I would say you have a carb problem.<br /><br />Let's see, improper adjustment of float height, bad inlet needle, stuck choke... Sounds like you need to rebuild it.

 

[ron7000]

Re: Over rich idle condition????

Originally posted by Limited-Time:<br /> Adjusting or removing idle mixture screws has no effect on RPM or vacuum readings. Carb was just rebuilt to original specs.

what engine and carb is this?<br />if turning the idle mix screws 1 turn either way has no effect on rpm, or anything, then you have a bad metering circuit in the carb. When the thing was rebuilt, were new idle mix screws installed or the old ones reused? They are also easily damaged, either the screw or the mating surface in the carb, if tightened inward too tight.<br />I don't know what you have but if you went so far as to a new engine, you might want to consider spending a few hundred more on a new carb. Don't let your old carb ruin your new motor if it can't be fixed. Over-rich mixture will result in fuel in the oil, diluting it to the point wear it no longer lubricates, wear and engine damage is the result.

 

[Limited-Time]

Re: Over rich idle condition????

Thanks for the responses well all but KG's anyhow. The engine is a 5.7 with a Carter/Weber/Edelbrock/.....four barrel. I rebuilt it using the components supplied in the kit; replacement idle mixture screws were NOT included in the kit so the originals were reused. I'll have a new carb by Friday. Just want to make sure I'm not missing something simple.