Hi all
My 2006 mariner 15 2 stroke has been running progressively rougher of late so I decided to strip and clean the carb today. I should have taken some pics but it's very straightforward. Furthermore, here's a link I found to the service manual, you need section 3A-14:
https://www.google.co.uk/url?sa=t&rc...41320020,d.bGg
There's a metal plate behind the primer knob, slide this out, then partly unwind the phillips screw just inside and to the right of this plate. The primer knob, shaft and plastic thread then pull out of the carb.
The carb is secured to the engine with 2 12mm nuts, you can't miss them. As you lift the carb out there is a small spilloff pipe underneath that needs removing gently.
The plastic primer lever is held to the carb with 2 8mm bolts, remove this. There are then 3 items to undo in order to get right inside the carb. first the metal plate at the top of the carb held on by 2 dome head bolts. Then the primer chamber on the side of the carb, held on with 4 dome head bolts. This has a spring in it so take care removing the top. Finally turn the carb upside down and undo the bolt at the base of the carb bowl. take out the float and carefully remove the needle behind the float arm.
Don't take the pump assembly (left hand side of carb) apart unless you intend replacing the pump diaphragm, it says in the manual not to.
I used an aerosol can of carb cleaner with a length of old rubber fuel hose attached to it. Spray clean all the bits you can get to, and then go round all the jet holes you can see including the two small jets on the part of the carb that faces the engine. You need to wear goggles because you must press the rubber hose firmly against these tiny holes and give it a good jet of pressured carb cleaner. This has a habit of jetting back at you if you're not holding the hose down firmly enough.
I would leave the carb to dry out overnight before refitting it and running the engine up. The only fiddle I refitting the primer knob and shaft, it's a fiddle but not impossible. If you have some cash (I don't) then it would be a good idea to replace all the gaskets and the pump diaphragm.
Anyway, the engine is ticking over a treat now and I'm looking forward to getting it back on the water!
Whilst googling 'mariner mercury 15 rough idle' I came across a post where someone had discovered that one of the two exhaust holes at the top of the outboard leg had become completely blocked. I checked mine, and it was indeed completely blocked. To be honest, I thought there was only one hole but next to it was another completely blocked one, difficult to spot. Used a 5mm hss drill bit to remove the crud
Hope this is all useful to someone with a similar engine. Note that this is the Brunswick mariner/mercury 15, not the tohatsu one.
Cheers
Simon
