Mariner 9.9 2 stroke- sputters at first pull then not again unless it sits?

[sfbaysailor]

Hello wonderful forum of smart people. Thank you for your help.

I bought an 1987 Mariner 9.9 2 stroke that took a lot of pulls to get going but once it did, would run great, and start-up on the first pull after it was warm. This worked well for a few months on my sailboat, but then I left it untouched in the marina for another 2 months, and when I returned, it would not even fire no matter how many times I yanked on it. So, I started working down the list. Changed the plugs, (and saw spark when grounded to the engine block), cleaned the fuel filter and got fresh gas, nothing. Thumb-checked compression, seems fine.

At this point I pulled it off the boat and brought it home for surgery. Removed the carb and cleaned it with carb cleaner. Looked really good, but made sure all the ports were clear anyway with cleaner and a wire. Replaced all the gaskets. By this point I was out of time, and left the test for another day.

Next day I got the motor in a trash can, primed the pump, and on the first tug, she fired for maybe 3 seconds. Rumbles of life! But then, nothing. After a few minutes of tugging and fiddling with the choke, adjusting the idle screw, and trying carb cleaner in the intake, I walked away, frustrated. Next day, same thing. On the first pull after sitting, she coughed and sputtered to life then died, and wouldn't kick over again even with carb cleaner.

Any ideas what such behavior might indicate?

 

[MH Hawker]

lack of fuel and a do over on the carb

 

[flyingscott]

Did you use a complete rebuild kit on the carb with the fuel pump and primer diaphragms? How did you clean it? did you do a compression and spark test on it?

 

[sfbaysailor]

Cleaned by spraying all the ports I could find with carb cleaner. Is a few hours in a vinegar bath the proper way to clean it? I did change the fuel pump and primer diaphragms. Opened it back up last night and there was some gelatinous goo in the primer diaphragm. Did not do a full compression or spark test. Ordered a compression kit last night on Amazon. What does a spark test look like other than seeing a spark when grounded to the block?

 

[flyingscott]

You need to soak the carb in regular carb cleaner. Did you service the ball and spring for the primer? It sounds like your motor is flooding out.

 

[sfbaysailor]

So, I did a compression test and got 90 in one cylinder and 100 in the other. Sound reasonable?

 

[racerone]

I think the main problem is your starting procedure.-------Find a manual .----Or run to a shop , buy some sparkplugs and oil and have them show you the starting procedure.-----I believe you are missing something simple.

 

[sfbaysailor]

Ok, Soaked the carb really well, and am just waiting for a replacement part, but I did discover there was no choke ball in the primer bowl. Is there also a gasket that's supposed to be in that setup? If so, I think I melted it out, otherwise it was a ton of buildup. Either way, have the repair kit on the way, although it kinda sucks that I have to get yet another set of gaskets and a bunch of spare parts I don't need all for a tiny bb and a gasket. Ah well, hopefully I won't need those other parts for a while

 

[flyingscott]

There is a seal in the in the primer assembly a small one that gets pressed in. Those parts are available separately and that will definitely cause your problem.