Carb Problem
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=2250
Printed Date: June-17-2024 at 4:39am
Topic: Carb Problem
Posted By: SkiLew
Subject: Carb Problem
Date Posted: August-15-2005 at 12:09pm
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Has anyone had a problem with their engine wanting to idle too high after it has been run real hard.
I Have a 1993 351 engine with the standard Holley Carburetor. Sometimes after I have run the boat really hard the idle rpms will be so high that I am afraid to put it into gear for fear of damaging the transmission. If I shut the engine off and let it sit for just a minute or two and then restart the engine, it will usually idle normally. Again this only happens when it has been operated at nearly full throttle conditions. Any thoughts? |
Replies:
Posted By: GottaSki
Date Posted: August-15-2005 at 12:54pm
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The secondary throttle plates are likley hanging open a snudge.
First adjust the pivot on the throttle cable so that at idle, the cable gently pushes the throttle against the idle stop. Then, adjust the closing linkage to the secondary throttle shaft so that it forces the secondaries fully closed, and doesn't permit it hang open. You will need to adjust the bend in the rod with two pliers. If you can rotate the secondary shaft with your fingers when at idle, you can hear the rpms change, and it needs adjustment to prevent your symtoms. Another, less likely cause could be the mechanical advance getting stuck and not retarding till you shut down, pop the cap off and check for smooth operation and no broken springs; if it flops around and does not spring back, a sping is broken; if its sticky, well, it needs lube. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: Jim_In_Houston
Date Posted: August-15-2005 at 1:06pm
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You may want to replace your PVC valve. Maybe it is sticking partially open and falls closed after the engine is off for a period. ------------- Happy owner of a '66 and a '68 Mustang |
Posted By: SkiLew
Date Posted: August-15-2005 at 8:01pm
I removed the throttle cable when this was happening but it did not make any difference. Therefore, I am thinking that the problem must be tied to the operation of the secondary throttle shaft. |
GottaSki wrote: