1989 Mariner 20HP

[bjjones74]

Hi, All... I recently purchased my first boat for fishing with my son...It's a 1989 Grumman Panfish I with a 1989 Mariner 20 HP outboard. When I first got it a couple months ago, it started right up but ran super rough, shaking like crazy and stalling out at idle. I did some standard stuff like a carb rebuild, spark plugs, fuel filter....basic things I can handle.

However, now that I have all that done, I started having problems just getting it started. I finally got it started and running today but it doesn't make sense to me. After messing around with it, I eventually removed the idle screw in the carb. I pulled the cord to start it, just to see what would happen, and it started right up and appears to be running smoother than it did when I got it. The minute I put that idle screw back in (even barely putting it in), the motor begins shaking and smoking like crazy. I take it out, and the motor smooths out and smoke decreases significantly.

I'm sure this sounds crazy and I'm probably not providing enough detail, but this is all new to me. I've been learning off of YouTube. lol.

Any thoughts or clues what I can look at next?

 

[flyingscott]

Did you clean the carb? Did you do the primer assembly? Fuel pump? all should have been in 1 kit. What is your compression? that screw on the front of the carb is not the idle screw. It is the low speed mix screw and should be se around 2 turns out.

 

[bjjones74]

Did you clean the carb? Did you do the primer assembly? Fuel pump? all should have been in 1 kit. What is your compression? that screw on the front of the carb is not the idle screw. It is the low speed mix screw and should be se around 2 turns out.

I did clean the carb and replaced everything included in the carb rebuilt kit. Unfortunately, I don't know the compression....like I said, I'm new to this. I am going to pick up a compression tester this weekend. Also, thanks for clarifying what the screw is. Before I removed it, I counted that it was originally out 2 1/2 turns. It's just strange that it runs so much better with that screw removed completely.....maybe I messed something up putting the carb back together.

 

[flyingscott]

Double check you used the right gaskets. Those kits contain gaskets that may not work in yours. Important to double check. Also make sure the base gasket is on correctly. If it is on wrong it will cover the pump pulse port. Is the ball and spring in the primer correctly.

 

[bjjones74]

Double check you used the right gaskets. Those kits contain gaskets that may not work in yours. Important to double check. Also make sure the base gasket is on correctly. If it is on wrong it will cover the pump pulse port. Is the ball and spring in the primer correctly.

I think I found the issue...and I'll chalk it up to stupidity. I'm missing the small bearing that is in the primer/injector of the carb. I put the spring back in without that bearing (not even realizing). I'm not at a point where I completely understand how the carb works but I'm guessing that I'm flooding the carb with fuel and having the low speed mix screw out is allowing in enough air to compensate for the extra fuel??? Now, I need to find that bearing that I've misplaced. I can't learn without trying it myself, though, right? LOL.

Thanks for mentioning the ball and spring. That prompted me to look it up online and when I had no recollection of seeing it earlier, that's the first place I looked. You saved me a bunch of time.

 

[flyingscott]

Yes you must have the bearing in. If you can't find it they do sell a primer repair kit the that has the bearing.

 

[bjjones74]

Yes you must have the bearing in. If you can't find it they do sell a primer repair kit the that has the bearing.

Thank you so much for taking the time to point me in the right direction. Without your replies, it would have taken me forever to realize I am missing that little bearing.

 

[flyingscott]

You bet. They are some of my favorite motors.

 

[airshot]

We have all done dumb things, that is how we learn !!! Glad you were able to find your issue.....