Any idea what jet size is for sea level 9.9 4 stroke?

NMShooter

Petty Officer 2nd Class
Joined
Mar 17, 2010
Messages
196
I'm in the process of buying a 2000 Merc 9.9 4 stroke, which has been in Colorado its whole life. It is now headed to about 1200' of elevation.

Owner does not know if this carb has been re-jetted for altitude. It needs a bit of carb work, as the float either sticks or is leaking. I'll be in there anyway to replace the float, needle, gaskets, and do a general housekeeping clean on it. I thought that I might as well check the jets and the nozzles to make sure they are sized for lower elevation.

Anyone know what the "stock" or low elevation needle and jet sizes are?

No... sorry. I don't know the exact model number yet. Looks like there were three made that year. My hunch is that the carb parts might not have varied too much, although perhaps the model numbers might reflect a high elevation version.

Thanks!
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,030
Contact a Dealer, provide the Exact Model info, and ask if there were any Altitude Jets. Alternately, if you want to sure you have correct Jet, order a new one
 

NMShooter

Petty Officer 2nd Class
Joined
Mar 17, 2010
Messages
196
OK... I wanted to circle back around and detail what I found out in case others need this info.
I called Mercury, and spoke to their tech folks (guy named Blake)

He said that for the little motors, it would be highly unusual for a dealer to mess with the carb jets and nozzles and that they would likely just change the prop pitch.

He said that in the manual, the factory carb jet / nozzle sizes for my motor, serial 0T110xxx were the following :

Main Jet #86, part number 66N1434334
Pilot Jet #48, part number 8027011 (oddly, a search for this number turns up a jet size #45)
Main Nozzle, part number 66N1434100

He said that the 2000 year series were a joint effort with Yamaha(!?) and that the 66N numbers above are no longer offered by Mercury, but might possibly be obtained from Yamaha. He said that the 8027011 number is still a valid Mercury number.
 
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