40hp merc carb problems

[lazzlonewolf]

i have a 40hp merc outboard. it wont run under a load runs fine in a barrel put it in gear tries to keep running. idles fine. iv replaced everything the stator all the fuel lines compression test 120PSI in each cyc.all new wires. fuel pump. plugs.new gas ,seafoam.I finally took it to the pros. they charged me $75 to say i had the wrong carb on it. i put the orginal on it an it ran like **** then it wouldnd even start. put the other carb on ran good again. but not under a load.the carbs are different one has a hose running out to the carb, i plugged it with a toothpick cause the float bowl i have dosnt have a connection for it. anyway i need to know where i can get a carb with #1368-5036 on it?? also i cant find the year of the motor s/n#3585874? the carb has WMK 8-1-1 on it? its a 38-1 38-2 38-3 i found one on e-bay with 8-1-0 on it will this work? or find a float bowl cover with that hose connector. help i want to go fishing before it gets cold..... Shawn in Michigan...

 

[MacDaddy21]

Re: 40hp merc carb problems

You have a 1973 Mercury 40. I have seen several carbs on ebay for 75 bucks that will fit your motor. Your motor is very similar to mine (I have a 1979 Mercury 402 40hp). Get the correct carb, and get a rebuild kit. Get new gaskets, and a new needle and seat. I would also recommend replacing the float with a new one.

 

[lazzlonewolf]

Re: 40hp merc carb problems

how ya know its a 73? iv seen those carbs for $75 i got all new stuff on the carb i have. it runs great in the driveway put it in the water under a load and it wont run?? iv tried everything even the merc macahincs cant figure it out. iv replaced every part of the carb and bowel..

 

[MacDaddy21]

Re: 40hp merc carb problems

I looked up the serial number for you and it came up as a 1973. If you are using the wrong carb for that engine, it is not going to run worth a crap. You need to get the right carb like the ones they have on eBay. My motor was not running well under load either, and I did a thorough cleaning on my carb and fuel pump and then rebuilt both, and my problem was solved.

 

[Mi duckdown]

Re: 40hp merc carb problems

Just rebuild the original carb

 

[lazzlonewolf]

Re: 40hp merc carb problems

where did ya look up that s/n at?? and i did rebuild theoriginal carb but it runs like ****. the other one runs great but they say its the wrong carb? did ya happen to find out what carb goes on this motor? Iv been searching everywhere cant find it. like i said i found some of those on e-bay for $75 and it looks the same. Im sure its a carb problem. Now i just need to know what carb goes on this motor?

 

[MacDaddy21]

Re: 40hp merc carb problems

http://www.iboats.com/basics/mercury.html

here you can find your serial number. Scroll down until you see the 40hp motors.

Here is the carb that you should have on your motor. This is the carburetor shown in the parts schematic for your motor found here

Parts Schematic:
http://www.crowleymarine.com/mercury-outboard/parts/460_6.cfm

Correct Carburetor:
http://cgi.ebay.com/ebaymotors/Merc...oatQ5fPartsQ5fAccessoriesQ5fGear#ht_755wt_903

 

[lazzlonewolf]

Re: 40hp merc carb problems

ok thanks very helpful.. Oh How do you know what Jet to use??

 

[MacDaddy21]

Re: 40hp merc carb problems

The jets are set diameters from the factory. Your carburetor has fixed jets. You don't have to change them unless you significantly change altitude.