Carburetor issues
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=43077
Printed Date: May-21-2024 at 3:25am
Topic: Carburetor issues
Posted By: restored82
Subject: Carburetor issues
Date Posted: July-02-2018 at 7:20pm
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My 82 nautique runs rich at low speeds and idle. I had the holley 4160 rebuilt some time ago. Having realized it was most likely set up in a level position on a bench. It seems likely that the floats are not set up to match the 15 degrees the engine sits at at idle or low speeds. Is it likely the float setting could be the culprit. Other ideas are welcome. If it is the float level how is it to be set up since it is an internal float set up.?And how much need it be adjusted? Thanks in advance for helpful ideas and input .Brian ------------- Jus Fishin |
Replies:
Posted By: bb12
Date Posted: July-02-2018 at 8:42pm
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Could be a few things. How are your plugs? How long ago was the rebuild? I believe on the old Holley’s with internal floats the fuel is supposed to barely drip out of the plug. How are your other ignition components? Wires, cap/rotor, Coil? ------------- 1989 Ski Nautique 2001 |
Posted By: KENO
Date Posted: July-02-2018 at 10:59pm
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If the float adjustment was too high you'd have lots of fuel dripping down the primary venturis and more drivability issues than just a rich mixture. At speed the carburetor is still at about the same angle as when it's idling. There's really no "special" adjustment needed for the mounting angle Any PCM manual has the float level set up just like an automotive application.although some people like to adjust the primary bowl float a little lower In 82 they had the internally adjustable floats which means you have to take the float bowl off to do it. The older ones that BB12 refers to could be externally adjusted Before doing anything with floats, I'd make sure the idle mixture screws are set right and that you're actually idling on the idle circuit.. A good starting point for the mixture screws is 1 1/2 turns out from seated. You can do a CCF search on how to adjust them or read a Holley manual Lots of info here on the website Somebody might mention a blown power valve causing issues like this also but that's not too common at all unless you've had a big backfire through the carburetor, then it's a "maybe" And like BB12 said make sure your ignition system is working as it should. |
Posted By: restored82
Date Posted: July-04-2018 at 5:11pm
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Thank you Keno and bb12 for your input .After a bit of pondering I will add more info; 1}Coil,cap , rotor and wires were new one hundred hours ago [time of rebuild] Carb was rebuilt then as well 2} the ignition is a pertronix ignitor 3} The jets are set at 2 1/2 turns by mechanic 4} the idle always fluctuates,never a flat idle 5}The stern is always coated some with black soot 6}the spark plugs foul more the further to the rear on each bank of cylinders fronts light beige the rears are black. I have new plugs to install 7] the engine has backfired through the carb a time or two Thanks again for your information and sharing your experience ,much appreciated, ------------- Jus Fishin |
Posted By: 8122pbrainard
Date Posted: July-04-2018 at 5:42pm
Brian, Do you mean the idle mix adjustment like Ken mentioned?
Did your mechanic use a vacuum gauge https://www.bing.com/videos/search?q=holley+idle+mix+adjustment&qpvt=holley+idle+mix+adjustment&view=detail&mid=483CDCEDCF2DA45BF339483CDCEDCF2DA45BF339&&FORM=VRDGAR" rel="nofollow - per the Holley instructions? Take a look at the video and note what problems can be caused by a bad idle mix adjustment. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
restored82 wrote: