1982 Mariner 50 HP carb adjustments

I have a 1982 mariner 50 hp outboard that im trying to find carb adjustment specs for. Can anyone help me out ? it runs rough and misses at idle. Ive spent way too much at the local dealer and have lost faith in them.

Thanks

I don't blame you, for that task is simple as pie. But your carbs can not be flooding or you'll be wasting your time, so check that first. (Easiest way to do that is match how it idles with the fuel connector removed. Most OBs tend to speed up just before running dry, but if yours idles better long before then, it might be flooding.)

Assuming the carbs are okay, do the following:

1. Warm the motor thoroughly
2. With the boat on the trailer, or tied fast to a dock (so it won't move and trick you) put it in gear
3. Take each idle adjustment, one at a time, and SLOWLY turn the needle IN (CW) until the motor starts to stall
4. Immediately turn it the other way (CCW) about a half turn. Then repeat the above for the other carb.
5. If the motor stalls when doing this, back the adjustment off, refire, and try again.
6. SLOWLY turn each idle adjustment screw one way, then the other, an 1/8 of a turn each time, searching for your best (smoothest) idle. Take your time after each adjustment and let the motor 'settle out'. Important!
7. Now that you have found your best idle setting, add 1/4 turn OUT (CC) to both adjustments.

Then take her for a ride. If the motor tends to bog as you open the throttle, add another 1/4 turn OUT (CCW) on the adjustments.

Good luck,

Jeff

I've tried following your instructions and im still not able to get it to run smoothly. When at the dealer, they disassembled and cleaned the carbs but did not rebuild them even though i had specifically requested it. Their mechanic said it wasn't required. I've had the motor for 4 years and have not touched the carbs and its a 40 year old motor. They didnt even call me to let me make that decision.(why not rebuild them if you have them out and disassembled for cleaning ??) They say compression is 120 across all 4 cylinders and the spark is strong. (I did find a very bad wire in the trigger harness that i had to cut back to within 2 inches of the trigger to find good wire and replaced the bad section). Dont know if there is a procedure to check the ignition system without having the proper diagnostic tools. I do have a multi-meter and know how to use it. I'm a mechanic, just not an outboard mechanic. Not sure where to go from here other than to buy kits for them. Getting a little frustrated.

There is not much that can go wrong with these carburetors !!----If they are clean they will work just fine.----Do the following test.-----Does spark jump a gap of 3/8" ( 1 cm ) or more on each lead, yes or no ?-----Have you changed the water pump impeller ?-----Have you checked exhaust passage for blockage ?------Serial # of your motor ?------Did the shop check for possible water leakage from exhaust covers ?---Perhaps lower crankshaft seal is leaking.----Some simple trouble shooting finds answers.