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  #41  
Old 09-29-2011, 03:34 PM
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JMann JMann is offline
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To follow up and hopefully get some advice. Unfortunately this is only the 2nd time on the boat since I did the rebuild and have a couple of questions.
The boat seemed to run a little rough and idle high. It ran fine and pulled strong just seemed a little rougher than in the past. Here are a couple things I did besides the carb.

1) I replaced the spark plugs with Autolite 24's. I took in the old plugs which where NGK and the guy at Napa said they compared to an autolite 23 which is a cooler running plug. I went with the 24 on the recommendation from here.

2) I took out all the foam in the engine box because it was falling off. could this make it seem to run rough?

3) The idle is at 750rpm and in the past it was 680rpm.

What do you guys think? Should go back to the old plugs and see if that slows the idle and smoothes it out a little or leave the plugs and adjust the idle on the carb?

Any advice would be great.
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  #42  
Old 09-29-2011, 04:00 PM
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changing plugs should not have changed your idle speed, maybe you got a plug wire or two crossed when you tuned it up. that would cause both of your concerns. if your wires arent crossed then you need to figure out whats causing the roughness and adjust your idle warmed up and in neutral. if it ran fine before you messed with it then it runs bad, logic would seem to dictate it has to do with something you messed with...
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  #43  
Old 09-29-2011, 04:25 PM
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I agree it probably has to do with something I messed with. I could have crossed my #6 and #7 spark plug wires when I changed the plugs. Is this the correct firing order?
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  #44  
Old 09-29-2011, 09:24 PM
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Yes, thats the correct firing order.
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  #45  
Old 09-30-2011, 11:22 AM
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If you do indeed have your wires crossed and experienced a good backfire through the carb, it may have taken out your power valve (been there). If so, you will be running full rich - won't take long to figure out if that's the case.
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  #46  
Old 09-30-2011, 12:59 PM
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I don't think I have the wire backwards. I was talking to a friend and he said you would have known if they were switched, e.i. no power and backfiring. I ran pretty well just seemed a little rough. I think I just need to dial in the carb a little better.
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  #47  
Old 09-30-2011, 01:53 PM
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Quote:
Originally Posted by east tx skier View Post
Correct. Get the correct torque specs for that fitting and do not exceed them. You can just back it of and retighten.
Quote:
Originally Posted by j.mccreight@hotmail.com View Post
Yes it is real easy to overtorque the fuel line where it enters the carburetor. If yours is leaking try loosening the line up and snug it back down, if it still leaks then replace the hard line and snug down...
The other area you want to insure the correct torques is applied is to the bolts for the fuel bowls back and front. In the PCM Manual for this engine as found on this site it quotes a TQ of 10 inch pounds let me repeat so there is no mistake 10 inch pounds not foot pounds!!! My suggestion is to step TQ it meaning that you take it to 5 inch pounds stabilize torque meaning that you go around once you have torqued the nuts and verify that they dont turn anymore. Then take it up to final torque, and once again insure the TQ is stabilized. The socket is a 5/16" for these bolts, and insure they have the seal on them.

Regarding your question about how to replace the o-rings on the fuel tube, yes you can do this work with carb installed in place. If done while in place and you go from secondary side you dont even have to worry about torqueing the fuel inlet line. My suggestion is removing the back float bowl, depending on the year of your carb there might be 3/32 clutch head screws holding the gasket in place with a plate. A smaller flat tip should work removing and reinstalling the screws. Yes fuel will leak from the bowl when breaking it loose from carb, place a rag or some other form of absorbent material under the bowl when GENTLY removing it.

Hope this helps and get you back out on the water.

In my haste to help out a fellow boater did not realize the thread started out almost a couple of months ago when I wrote my reply

Last edited by rjracin240; 09-30-2011 at 02:13 PM. Reason: Did not realize the start of thread was from almost a couple of months ago
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  #48  
Old 04-19-2012, 04:08 PM
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In order to avoid starting another thread I am going to continue this one. I have deteremined from talking to friends that know carbs and motors the reason it was running rough last season was that it was probably adjusted over the years to run smoother as the seals detiorated. I think I only have to tune the carb up and it will smooth everything out.
Does anyone have a step by step guide for dumbies to tuning the 4160 carb they could post or e-mail? Pictures would help so I know I am twisting the correct screws. It runs now and I don't want to make it worse by starting to turn the wrong adjusts, etc.
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  #49  
Old 04-19-2012, 04:53 PM
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The proper way to tune a carburetor is with a vacuum gauge hooked to to read full manifold vacuum, yes you can use pcv port with an adapter. The 2 small screws on the near the front and on the side of carburetor is the mixture screws. First turn screws all the way in then back them out 1.5 turns then you can adjust these 2 screws evenly in or out to achieve the maximum vacuum. All this is done with engine running, warmed up and in neutral, then finally verify idle speed is within specs.

Here is a nice rebuild walkthrough
http://www.fordmuscle.com/archives/1...lley/index.php
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Last edited by j.mccreight@hotmail.com; 04-19-2012 at 08:53 PM.
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  #50  
Old 04-19-2012, 09:00 PM
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A pic of mixture screw
and a holley video of using the gauge, some info is not applicable to your carburator.
http://www.youtube.com/watch?v=BZy2Y...feature=relmfu
http://www.youtube.com/watch?v=UPGLU...feature=relmfu
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Last edited by j.mccreight@hotmail.com; 04-19-2012 at 09:06 PM.
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1991 ps 190, carb, fuel problem, indmar

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