2.5 offshore 260 smoking badly at idle

[yrite1]

I have a 2.5 offshore 260, well that's what the mid says on it!, anyway it has all of the sudden started smoking at start up and I don't mean normal smoke I'm talking a lot to the point of embarrassment but as soon as u take off and start going it instantly goes away and runs just fine, it also has not been wanting to idle as well. It did not do this before winter came only now that I have taken it out for the first couple days of season. I know the motor is down on compression but they are all equal and it still hauls ass on the back of my HST. It obviously is loading up while trying to idle and it also does it even if the motor is a normal temp. I run the Mercury premium synthetic oil and I even tried mixing it the second time out at 40:1 but no help. Could this be that it needs new plugs as I have not changed them since I bought it ?? Thank u in advance for any help.

[tlwjkw]

year and ecu number would be a good start.... picture of tha power head....

[Flatlander]

could be your air temp sensor went bad causing it to go rich

[johnmiffco]

I run trip motors and when 1 motor starts smoking more at idle
its usually a plug or 2 wetter than the rest,,,
change em and go,,,but mark which cyls they were
and if smokes more again shortly'
and on same cyls
then go to checking coils and injectors on them cyls

[yrite1]

[yrite1]

That's kinda what I figured, thanks for the help

[tlwjkw]

well, that eliminates analog and tpi.... could be a few things but without being there i have nothin' by bein' ona computer!... don't wanna steer ya in tha wrong direction with a "very nice piece" like ya got there!... sorry. maybe these other guys can get ya goin'......

looks like that thing has never hada screw turned on it!!!

[Baja170]

No kidding, that is the cleanest 260 I have ever seen that has been run. WOW. Nice!!


Good luck solving the problem. I will be watching for this phenomenon and I have a spare set of plugs with my 260's. Thanks for the info!!

[ChrisCarsonMarine]

Check your reeds,Chris

[superboattwin250]

Could be the reeds, air temp sensor is out of wack, injectors need to be cleaned or the very basics like spark plugs and the barb fitting that gives signal to the ecu is clogged.

[Flatlander]

I have a 2.5 offshore 260, well that's what the mid says on it!, anyway it has all of the sudden started smoking at start up and I don't mean normal smoke I'm talking a lot to the point of embarrassment but as soon as u take off and start going it instantly goes away and runs just fine, it also has not been wanting to idle as well. It did not do this before winter came only now that I have taken it out for the first couple days of season. I know the motor is down on compression but they are all equal and it still hauls ass on the back of my HST. It obviously is loading up while trying to idle and it also does it even if the motor is a normal temp. I run the Mercury premium synthetic oil and I even tried mixing it the second time out at 40:1 but no help. Could this be that it needs new plugs as I have not changed them since I bought it ?? Thank u in advance for any help.

Were you able to figure out what was the problem?

[W2F a V-King]

I run trip motors and when 1 motor starts smoking more at idle
its usually a plug or 2 wetter than the rest,,,
change em and go,,,but mark which cyls they were
and if smokes more again shortly'
and on same cyls
then go to checking coils and injectors on them cyls

Agreed

A slow leaky (or dirty) injector bleeding down into a cylinder or two could cause that symptom.
When you pull the plugs you will hopefully see which cylinder/s is loading up.

What a nice clean mil !!! Great maintenance

James

[nelson edens]

Check the orfice that goes to the TPI. It blocks easily and often. It is easy and cheep (free) to check!!

[yrite1]

Have not had time to work on it yet but I will for sure let u guys know what vI come up with. I really appreciate the help guys

[texasvector]

Hole Lee sheet....that's 1 clean motor

Simple things first. .plugs...reeds...etc.etc...

Do what these guys said and report...