Hints on 22 CID ('75 25 HP) Evinrude idle?

[jspringator]

Any hints on how to improve idle on 22 CID 'Rude? There was apparently a thread on this in 2006, but I can't find it. It addressed some sort of oil recycling? I decarboned all day yesterday and took it on the cold lake today. Man it ran smooth in its cruising range. Really too much power for my boat at full throttle. It has what I read to be a "lean sneeze". I richened the mixture and it idled much better, but the idle does not correspond with the throttle settings. Thanks!

 

[F_R]

Re: Hints on 22 CID ('75 25 HP) Evinrude idle?

Enrichening it just enough to eliminate the lean sneeze is the correct setting.

Starting around 1973, they began eliminating the overboard dumping of crankcase drainings. They did that by running the drained fuel through the cylinders to be burned. Well, the facts of life are that the old motors idled great because of draining off the fuel and getting rid of it (by dumping it overboard). In the interest of environmental concerns they can't do that any more and there is a price to pay...they don't idle as well. Yes, mid-range is affected too.

Edit: Fast forward a few years and they idle better again because they redisigned the crankcases to make them more efficient, thus less drainage to contend with.

 

[jspringator]

Re: Hints on 22 CID ('75 25 HP) Evinrude idle?

Can anyone give me an idea of which hose is responsible for this "reburning"? There are 2 suspect hoses. Can I plug the top one and drain the other one overboard?