150 Force smokes

[force 150 fl]

I have a 1991 150 force ob that I rebuilt last year . It has good compression and starts up no problems and runs good but it smokes a lot . I try external fuel tank with a fresh mix 50:1 and still the same problem . I replace the carbs with new ones and still smokes the same . I notice when I was doing my compressin test a lot of raw fuel spraying out of #3 cyl only and it had good compression . Can a fuel pump cause this problem and lead to my over smoking engine ? or could I have a broken reed valve or something in the lower end (crank seal broken )? sometimes I will see oil drip from my exhaust port after running with ears in my driveway . Thanks for any input I can get ! 150 Force Fl

 

[steelespike]

Re: 150 Force smokes

Check for a leaky fuel pump diaphram letting raw gas into one of the cylinders.

 

[force 150 fl]

Re: 150 Force smokes

Thanks for the reply steelspike . I have removed the fuel pumps today and the diaphrims look good no rips or holes in them . haven't replace them yet but can they look good to the eye and still be bad ?SteelSpike could I have a bad reed valve or broken crank seal ? sure hope it's not a crank seal . Thanks again for your help . Jim

 

[steelespike]

Re: 150 Force smokes

Not likely to be a reed valve.You would<br />likely hear it chuffing and see it puffing <br />out of the carb(s)I dont think a seal would cause problems on only one cylinder.<br /> I sure would suspect something involved with<br />number 3 the carb,fuel pump,Maybe a weak spark<br />but that is a reach.<br /> If the plug on 3 seems cleaner than the other cylinders you may have water leaking in causing a smoke like condition.