FORUM RULES UPDATED - The forum rules have been updated to continue to provide a friendly and safe environment for our member community. Please take a moment to review the updated rules and our terms of use and privacy policy. Click here for Forum Rules which has links to the 'terms of use' and 'privacy policy'.
I was trying to tune up the carbs to make the motor run smoother and when the motor died white smoke came out of the top carb. What would cause this? Its a 71 Mercury 650.
Its still running rough. It shakes at idle. I'm not talking a little bit of shaking, I mean like I have a Harley Davidson motor setting on the back. Tuning boat carbs are much different then tuning motorcycle carbs so I'm lost. I don't even know where the air/fuel mixture screw is.
manuals are worth their money, always check carbs by screwing in fuel adjustment screw til it stops count by half turns. then when you remove fuel adjustment screws, turn all the way in and back off same amont of turns as you had counted before. there is under carb and one to side and another sometimes behide brass hex plug on carb.
