2+2 concept 2003 115 merc

[merc jr.]

How do the "sleepy cylinders" and main bearings get lubricated when the engine is running below 1800 rpm? How long has this system been in the merc lineup and is it still?

 

[05GlastronSX]

Re: 2+2 concept 2003 115 merc

I believe that the "2+2" engine came around in the late 80's and has been used since 2004-2005 season. Now that the major manufactures have stopped manufacturing carbed 2-strokes in 2006, they are no longer made. The reason for the 2+2 was to smooth out the idle but i am not sure on your other question pertaining to the way the other 2 cylinders are lubricated. My guess is that the other 2 cylinders that are "shut off" get small amounts of oil to lubricate the cylinder walls, bearings, ect, but just enough not to foul the plugs because once you go over 1800 RPM and your other 2 cylinders kick in, you need a little oil to lubricate them enough until the oil pump is operating at full, normal capacity.

 

[phatmanmike]

Re: 2+2 concept 2003 115 merc

the OTHER cylinder, the ones not firing, , the carbs for those cylinders do not have idle circuits. if you get 2 more top carbs, and replace your bottom carbs with them youll have a "normal" motor.<br /><br />they get just enough fuel to lubricate, but not enough to fire!