Long run, motor smoking on slowdown - Evinrude 140?

Question

Just took my new (used) boat for a nice evening run. Went about 15 mi up the river and back at a decent clip. When I slowed down to enter the marina it started to run rough and smoke - blue fuel-smelling smoke. Is this normal?

Answer 1

yes you might have put to much oil in the gas tank

Answer 2

sounds like your oil mix is too rich

Answer 3

No, it's not normal.  Don't panic, but I'd do a through check of the engine, beginning with a compression check!  You didn't say how old this motor is, or when it was last run, but you could have a number of things to check out.  If the engine has been sitting for a while, the water pump impeller might have taken a "set", thus the engine is getting to hot.  Another possible problem is fuel related, but what I'm concerned about is the rough running and blue smoke.  This might, and I'm just saying, might indicate a piston problem...... This motor has a history of dropping the #2 Cylinder  check it out now.

Answer 4

You didn't state what year it was.   Some of the older models from the 1980's had problems with the VRO (variable ratio oil) injection system pumping too much oil into the engine under the conditions that you described.  I had a 1984 185hp that did this.  I bought it new and took it back to the dealer several times and they ultimately replaced the VRO unit.  That solved the problem.  It still smoked more at idle than I thought it should, but it ran fine and didn't bog down like it did before.  If your motor is is early to mid 1980's vintage with VRO, that might be your problem.

Answer 5

Time since last carb rebuild?

Has it been reluctant to start warm, so you have to raise the hi-idle lever a bit?  If so, your float valves & seats are starting to wear, and little bit of fuel is leaking past, giving you a slightly rich condition.