Mariner 15hp 2 stroke misbehaving!

[sunquest]

My 2004 Mariner has beaten me, I think I’ve tried everything.
It starts on first or second pull and runs smoothly although it momentarily misfires with a cloud of smoke.
Then when you open the throttle either in gear or manually at the carb the engine dies unless you press the blue choke button and it will rev high and die unless you press the blue button again.
I have stripped the carb and sprayed carb cleaner through every orifice. The carb is and was extremely clean and I am stumped. Any thoughts or ideas much appreciated
Thanks in advance. Geoff

 

[RichardS]

I'm afraid that dying when the throttle is opened is the classic "dirt in carb" symptom.

Certainly change the plug to see what happens but I think that you will be back to the carb. :ambivalence:

Richard

 

[TSB240]

I'm afraid that dying when the throttle is opened is the classic "dirt in carb" symptom.Certainly change the plug to see what happens but I think that you will be back to the carb. :ambivalence:Richard

I agree almost certainly Hi jet is blocked. I use a few strands of thin copper wire to clean mine and it ensures any hard deposits not cleared by carb cleaner are removed from the offending orifice. Soft copper will not damage a brass jet.

 

[QBhoy]

Jet or float sticking. Likely the latter of you have cleaned the jets already.

 

[SAMYL]

Poor fuel supply from the tank, air vent not open, blocked jets etc etc.
Carb cleaner not really much use unless you have physically removed all dirt and debris from the jets etc.
Use copper wire as above.

 

[longjohnsilver]

I have a 15hhp Yamaha that has occasionally done the same. Cleaning the jets cured the issues.