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Mercarb two barrel rebuild result question

rick3452

Regular Contributor
Hi guys, last week I had my Mercarb two barrel rebuilt by a Carburator shop. He said that the float was way low and the power piston was bent. So it's running good, full,power is good, idle is good also. The only difference is now after running and shutting down for an hour or so it starts hard... I actually have to give it a couple of pumps to start it. Before I just touched the key and it would start immediately never having to use throttle . Any ideas??
thanks !
rick
 
What motor? what year? raw water or closed cooling?

DETAILS DETAILS DETAILS!!!!!!!!!!!!!!!!!!!!!!!!!!
 
It's possible that it was flooding before, which supplied the gas it needed to restart with pumping the gas. What happens now is preferable, right?

Jeff
 
Sorry Jack I should know better! 2000 M/C 5.0 0m012817 closed (half) system 1700 hrs just did new cap, rotor plug wires, and spark plugs.

Jeff, when I went to see The guy that built the carburetor to explain the new starting procedure he suggested that was exactly the problem, it was dripping gas before, so it would start easier.
 
When a motor cools down it may or may not start without some additional gas supplied by "pumping" the throttle once.

What I would suggest is just push the neutral button and advance the throttle to about 10:30 position (do not pump). Just past the detent.

This will open the throttle blades just a little and give you a small shot then hit the key. You will figure out exactly how far to move the throttle by the rpms it runs at when started. Try to keep it around 1000 for about 30 seconds then drop it back to neutral all will be good!

If this works then this is what is needed. Mine also needs this from time to time after sitting for an hour or so, so nothing uncommon about this in my opinion.

What is your in gear idle rpms? Sometimes increasing the idle rpms (in gear idle not neutral idle) can make starting a bit easier. Spec is typically 650 to 750 rpms in gear.
 
Yes Jack, I set the RPM in gear, tied to the dock at 650 I initially set the carburetor idle speed down to 500 turned in the air mixing screw to it almost stalled open it up about a turn and a half and I left it there. Then I did reset the idle to 650 in gear as mentioned
thanks for the response really appreciate it....
Rick
 
Jack I tried the at 10:30 setting Seemed to work just fine, stats fairly quickly maybe within maybe 5 seconds so I'll just do that from now on. I was just concerned that it was totally different from the previous way of starting it meaning touching really nothing on the throttle.
thanks again....
 
Maybe try raising the rpms a tad and check your timing..maybe it is off a bit.. i think 6-8 btdc...
 
It should fire right up not 5 seconds....not sure at this point...getting late in the year to think straight...lol
 
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