7.5hp mercury smoking badly

[karaandjeremiah]

i got a used 7.5 hp mercury about a year ago. I ran it a few times right after i got it and it seemed to run fine, then after it sat for a few weeks i ran it again and it produced white smoke from all over around the lower end. It smells like exhaust but seems to be producing an awful lot of it. Any suggestions on how to go about diagnosing this problem? Also it will run, but it seems i can rarely get it to idle low enough to switch it into gear. What should be set where?

 

[andrewkafp]

Re: 7.5hp mercury smoking badly

Is your fuel/oil mixed at 50:1?<br />Is it peeing water out of outlet/telltale.<br />If so , How warm is the water ?<br />What year is it ?

 

[karaandjeremiah]

Re: 7.5hp mercury smoking badly

the fuel is mixed at 50:1 also it does pee out the side, but i've never felt it to see if it was warm or not.

 

[karaandjeremiah]

Re: 7.5hp mercury smoking badly

and i'm not sure what year it is exactly. my best guess would early 80s but thats solely a guess. is there any way to find out?

 

[andrewkafp]

Re: 7.5hp mercury smoking badly

The 7 digit S/no is on the bracket. If the water is hot (cant keep hand under stream for long) after a few minutes, then it's running hot and the top cylinder is cooking. It needs a new water pump impeller. It is normal for a 2 stroke to blow a bit of smoke until it warms up, so it could just be cold.

 

[war eagle]

Re: 7.5hp mercury smoking badly

Hey,<br />I have a 2 stroke 25hp and it will smoke for a little bit intill it gets warmed up then it will not smoke as bad,2strokes are sopposed to smoke some.Also if you add to much oil it will smoke a bunch.If that is the case add some more gas to the oil.It should have on back of the oil you buy how much oil you need to put in per gallon of gas.Try these and maybe you motor will get back to running right.<br /><br />shawn<-------

 

[karaandjeremiah]

Re: 7.5hp mercury smoking badly

ok, so now i've found out that it is a 1977 model, while running the water that comes out of the pee hole does not get hot. i've greased the zerg fittings and it might have been coincidence but it seemed to smoke less after that. It still smokes but it's not making quite as much as before. However now i can not get the idle under control. It will start, but constantly sounds like it will die. If i change the throttle at all it does die. I've messed with both idle adjustment screws and they seem to have no effect. I've taken apart the carb and rebuilt it. everything seems to be in order so now i'm at a loss. any suggestions?

 

[b22smith]

Re: 7.5hp mercury smoking badly

If you are running it in a barrel it will smoke REALLY bad, but it sounds like you are running it with the muffs and waterhose. Your idle screw might be running too lean, have you adjusted it out any (counterclockwise).