Mercarb issues

[Jcris]

Posted yesterday and I must have blown that so I’ll try again Decided to pull the mercarb 2 barrel off my boat to replace the plastic float with a brass one. At the same time I figured I’d check my recent rebuild effort and just go through everything and make sure I didn’t blow that too. The first thing I saw was a damaged intake gasket. When I rebuilt it I matched up existing gaskets with the new ones. The whole center section separating the 2 barrels is gone. Looks like it’s been torn off. I also noticed that a hole in the bottom of the carb was covered by the gasket. That doesn’t seem right to me Please take a look at the pictures. What’s that hole for ? I sprayed some brake cleaner in there and couldn’t see where it led to, if anywhere. Which gasket is correct?I checked the rebuild again cuz if this boat sits for more than a day it’s a bear on cold start.

 

[Jcris]

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[Bondo]

Ayuh,..... Is the plenum 2 holes, or oval,..??

 

[Jcris]

2 holes

 

[Jcris]

The area across the bottom of the carburetor casting is recessed between the ports . As the gasket gets saturated with gas it will soften and tear away. Am I seeing that right?

 

[Jcris]

So I re-checked the float level and drop. I set the level so the brass float was level. When I checked the drop it was set at around 1 3/4”
to bottom of float. If I’m not mistaken it should be 1 3/32” to bottom of float. Measurement taken from gasket surface to lowest point on float. If I set the drop to the 1 3/32” specification it doesn’t seem like there’s much difference between level and drop. Am I measuring wrong?

 

[Jcris]

If the float drop were off by that much, how would that affect cold start?