Very smokey 260 at start up

[rcleaver]

I have recently purchased a used 260 Mercury. I believe it has not been started for two years. I had the injectors checked before I started it a couple of times for about 5 minutes and when I did it blows a large amount of smoke that looks and smells like oil. It also has a strong smell of petrol after shut down. I have been advised to give it a good hard run to blow out any excess oil that may have accumulated in the cylinders whilst standing or may have been put in for storage. I am reluctant to run it in case there is a problem. Any suggestions please????

[gringo]

Hey mate if you have no luck with it, we will swap ECU, s on the 18th or if you get desperate before then talk to me and borrow it before hand. Thinkink about it my 260 was a smoker at idle when it had the analoug ecu and remote TPS just like yours and when i put the Brucato ACU on it the idle quality was like twice as good...
Cheers.

[patchesII]

Check the map sensor tube and the small barb on the horn that it plugs to. Use brake cleaner and compressed air to clean out the small hole in the barb. Don't use a drill that may enlarge the hole. If the tube or the barb fitting is clogged it will do what you describe because the ecu is seeing no vacuum, therefore it thinks the motor is wide open so it is dumping fuel like you're at wide open throttle

[M. HARDEE]

I agee with eric , I would also have the injectors sent to brakoto and cleaned ----two yrs sitting up ---iif the barb is gumed its a long shot the injectors will not be also and will not spray properly.

[T-REX]

Also see if theres a wire hook'd to tha solonoid(yellow/red stripe post) and goes to the ECU harness...If so, take it off...It "chokes" tha mota ever time U start it!!....

[Tom Foley]

Check the map sensor tube and the small barb on the horn that it plugs to. Use brake cleaner and compressed air to clean out the small hole in the barb. Don't use a drill that may enlarge the hole. If the tube or the barb fitting is clogged it will do what you describe because the ecu is seeing no vacuum, therefore it thinks the motor is wide open so it is dumping fuel like you're at wide open throttle

I routinely clean mine with a piece of wire from a trash bag twist tie and a length of Tygon hose to ease the application of carb cleaner or powertune . I usually remove the hose to the ECU , ream the soft crud with the wire gripped with needle nose , then fit the hose , juice it with solvent and let it sit a while . Then come back and blast it clean . When I used Pennzoil full syn . it seemed to clog up faster . Both my 260s smoke a lot at startup but then clean out .

[rev.ronnie]

Mine smokes pretty good when you fire it cold after launching, Especially when you hit the enrichment function. I usually hold it at 1500rpm and bump the enrichener occasionally till its warm. I especially love how the smoke cloud and cackle annoy the hell out of all the other passengers in the other boats at the launch...except for the guys who own them, they look over and drool...especially if they have a FOUR stroke. :)

[Hank W]

I routinely clean mine with a piece of wire from a trash bag twist tie and a length of Tygon hose to ease the application of carb cleaner or powertune . I usually remove the hose to the ECU , ream the soft crud with the wire gripped with needle nose , then fit the hose , juice it with solvent and let it sit a while . Then come back and blast it clean . When I used Pennzoil full syn . it seemed to clog up faster . Both my 260s smoke a lot at startup but then clean out .

I will be doing the same from now on. Both the MAP fittings & ECU fittings were gummed up on my 260 & my Bridgeport at the end of this season. I had to force a stiff wire through them & use carb cleaner. As far as I know, that had not happened in 10 previous years. Whether right or not, I'm going to blame the damn ethanol in the fuel.