912 carb setting

[Dave S]

Hi Don,

Those of us who have the airbox find that there is a nipple on each side of the airbox designed to receive/connect to the carb/bowl vents. If some fuel burped back - it would then go into the air box chamber.

Also thanks all for the discussion on the carb adjustment & slightly rough running in the range indicated - I do have experiences very similar to Dan - and it seems seasonally/temp connected - not bad but noticable.

Dave S

[wadeg]

I did my 200 hour service today with a Rotax repairman. Most of the work was simple and I had actually done a lot of it last fall during my annual but I wanted to see if I could learn a few things from him.

I had noted roughness in my engine at different rpms and it seemed to be worse at about 3000. We noted that a few plugs were darker than normal implying rich running. We dropped the carb bowls and found that the floats were riding a little too high causing the fuel level down there to be above normal. They were adjusted and things really were smoother before any sychronizing was done. Also, my plug gaps were a tad too large and they were remedied. I am surprised at how much smoother it is through the whole range. I was thinking a needle position change was in order but not the case.

[Slyfox]

the bing will run rough if the mid range jet gets plugged on the vent. The vent goes to the inlet of the carb right where the filter hooks on, it has an opening of lets say .020. it is really small. The best thing to do is remove the bowl and take some carb cleaner and remove the jets and spray into the hole, you will see the stuff coming out the vent. your done and you will be supprised at the difference in the runing of the engine at mid throttle. I usually do this at oil change and I also take all the other jets out and spray the circuits. hope this helps.