running rich at idle

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   Ok after it warms up 1985 2001 351W. it is very smokey in the back seat . like it is running rich . compression is about 140 across the board. carb has been rebuilt since then i changed the dist. a blew out the power valve (had dist backwards) . Changed the power valve to an 8 (i think) higher than stock (2) i think . Is this my problem ?. sitting in the back at idle with kids is not fun 
would a new carb help ? don't really want to throw 500$ at it . 
other than that boat runs great tops out about 45mph 
any ideas would be great 
thanks 
Dan 

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malibud Members Profile Send Private Message Find Members Posts Add to Buddy List Gold Member Joined: July-08-2009 Location: north carolina Status: Offline Points: 613	Post Options Post Reply Quote malibud Report Post Thanks(0) Quote Reply Topic: running rich at idle Posted: October-23-2013 at 1:07pm
	Ok after it warms up 1985 2001 351W. it is very smokey in the back seat . like it is running rich . compression is about 140 across the board. carb has been rebuilt since then i changed the dist. a blew out the power valve (had dist backwards) . Changed the power valve to an 8 (i think) higher than stock (2) i think . Is this my problem ?. sitting in the back at idle with kids is not fun would a new carb help ? don't really want to throw 500$ at it . other than that boat runs great tops out about 45mph any ideas would be great thanks Dan

Nautiquehunter Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum Member Joined: December-31-2008 Location: Lake Lanier GA Status: Offline Points: 1010	Post Options Post Reply Quote Nautiquehunter Report Post Thanks(0) Quote Reply Posted: October-23-2013 at 1:58pm
	Is the carb mounted at an angle? If so the float level in the front bowl has to be lowered.

malibud Members Profile Send Private Message Find Members Posts Add to Buddy List Gold Member Joined: July-08-2009 Location: north carolina Status: Offline Points: 613	Post Options Post Reply Quote malibud Report Post Thanks(0) Quote Reply Posted: October-23-2013 at 2:00pm
	no I do not think so it is stock . and i do not have any fuel dripping when running . but I could lower the front float if it would help.

phatsat67 Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: March-13-2006 Location: Indiana Status: Offline Points: 6157	Post Options Post Reply Quote phatsat67 Report Post Thanks(0) Quote Reply Posted: October-23-2013 at 2:03pm
	Lots of variables. Is the timing right? Did you go by the idle mixture procedure? What is the idle rpm? The power valve everyone goes with (correct if wrong) I think is a 6.5? If the vacuum isn't right the valve could be opening but you will need a gauge to check that. The number means the vacuum level that the valve will open at.

malibud Members Profile Send Private Message Find Members Posts Add to Buddy List Gold Member Joined: July-08-2009 Location: north carolina Status: Offline Points: 613	Post Options Post Reply Quote malibud Report Post Thanks(0) Quote Reply Posted: October-24-2013 at 11:56am
	went back and checked idle mixture screws turn all the way in and nothing happens all the way out and no change in vaccum . Ideas ? new metering block ? PV ? dont want to start throwing parts at it . float level is about level when turned upside down thanks Dan

phatsat67 Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: March-13-2006 Location: Indiana Status: Offline Points: 6157	Post Options Post Reply Quote phatsat67 Report Post Thanks(0) Quote Reply Posted: October-24-2013 at 12:25pm
	Dan, have you checked timing? Sounds as if the thing is running on the transition circuits rather than the idle circuits. This happens if say the timing is too retarded at idle and you need to open the throttle plates so much that it starts to pull fuel from the transition circuit in the barrel. I highly doubt a vacuum leak because that tends to cause a high idle lean condition not too much fuel. When idle circuits are working properly and there is no vacuum leak present you should be able to kill the engine easily with one idle screw closed. Did you get a vacuum reading on the gauge?

malibud Members Profile Send Private Message Find Members Posts Add to Buddy List Gold Member Joined: July-08-2009 Location: north carolina Status: Offline Points: 613	Post Options Post Reply Quote malibud Report Post Thanks(0) Quote Reply Posted: October-24-2013 at 12:47pm
	this on memory but timing is about 9-10 I advanced as much as possible before i got pinging on 87 gas. Vacuum is about 12. I wonder if my metering block might be bent? or power valve not right ? I can screw in the idle scres tight with no effects on the engine. I think this is causing the rich idle.

phatsat67 Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: March-13-2006 Location: Indiana Status: Offline Points: 6157	Post Options Post Reply Quote phatsat67 Report Post Thanks(0) Quote Reply Posted: October-26-2013 at 11:35am
	Vacuum is wayyyyy to low. A healthy 351 at idle out of gear should be up near the 20in mark and at or above 16 or so. The normal problem with a vacuum leak is that it leans out the fuel mixture from the extra air in the system the carburetor doesn't know is there. Could be that the power valve is blown out leaking vacuum and fuel? That seems like the most logical idea at the time. Cheap and easy to replace.

running rich at idle

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