Re: carb cleaning question 40hp 4 cylinder mariner
i would recommend you squeeze primer bulb for the few minutes that it takes to normally die and see if it still dies. My gut instinct is telling me fuel pump issue as the crank case pulses are much lower at idle and poor fuel pump performance shows here sometimes. Besides this is a free check
as fas as cleaning goes... i would think it very difficult to be assured of clean jets without removing carbs and complete tear down...so that you can actually look through the jets and assure that carb cleaner shoots through them nicely. Myself i use an $80 harbor freight heated ultrasonic cleaner and dawn dishsoap and set it to run for about an hr... sometimes 2 with all the carb parts in it. Don't use purple power simple green ect... as most of them will happily eat aluminum. if i have a particularly nasty carb that doesn't clean up well this way i use the green antifreeze in the ultrasonic on high heat and let it set overnight... a crock pot works too but you can never use it for food afterwords. the crock pot and antifreeze method will make your carb look like new as far as clean with an overnight soak on low setting... but will not remove oxidation from the aluminum.
I prefer the ultrasonic...
That said judicious use of carb cleaner and a full disassembly works well too.
If you find that sqeezing the primer bulb stops it from dieing then either fuel pump or fuel hose or fuel filter, can be an air leak or blockage.
oh... and if you remove carbs ect.... strongly suggest new gaskets for them, cheap insurance against air leaks in the future.
Sean
