Welch Plugs - Back Drag Carb Rebuild - 86 90 I6

J

jeff_smith_0423

Chief Petty Officer
Joined
Dec 5, 2007
Messages
492
Got my 90hp I6 back up and running. Ran great for about an hour on the river. and then would not idle. Pulled cowlings and found the bottom carb dumping fuel out of the vent jets. Read the plugs and 5+6 were lean, as expected. I'm going to rebuild all three carbs and try again.

My manual says to remove the welch plugs with a punch. However, I can not find carb kits that have replacement welch plugs. Is there anything behind them that absolutely must be blown out, or is a good soak enough?

Thanks again!
 
SeaKaye12

SeaKaye12

Lieutenant Junior Grade
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Jul 3, 2005
Messages
1,107
Re: Welch Plugs - Back Drag Carb Rebuild - 86 90 I6

Most any small engine repair shops would have the typical box of assorted welch plugs. Just refer to the parts diagram for your card which shows the correct sizes, or bring in your old ones for reference.

The welch plugs on my center bowl carb expose passages that exit behind the throttle plate. Soaking would probably be OK to clean those, but they are hard to visually check without pulling the plugs.

Pop them with a punch and just pry them out. Easy.

Chuck
 
L

lots of boats

Petty Officer 2nd Class
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Jul 28, 2008
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Re: Welch Plugs - Back Drag Carb Rebuild - 86 90 I6

When you put them back in use something like a smooth ball peen hammer, or even a large ball bearing. It is easy to dimple them down too far, and it helps to place the driver on the plug, then tap the driver. Just smacking the plug has mixed results.
 
C

Chris1956

Supreme Mariner
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Mar 25, 2004
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Re: Welch Plugs - Back Drag Carb Rebuild - 86 90 I6

Jeff it those are sidebowl carbs, you should be able to get them clean w/o removing the welch plugs. When you have completed the cleaning, you will want to reseal the plugs (welch and brass) with some silicone or other sealer.
 
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