yamaha boat motor 1986/150hp runs but if tiltit up the gas comes from carb and win runing it smokes bad?

Answer 1

check your floats in the carburetors

Answer 2

Gasoline turned to varnish in the four to six carburetors and now there is a problem. I remove the fuel line just before the dock run the engine until it stalls and pull out the oars to trailer the boat. That eliminates the fuel in the carbs. However some people say it dries out the float bowl gaskets. Improper oil mix and leaking rich running stuck needle and seats in the carbs make the smoke. After you spend lots of money removing the carbs and cleaning the fuel residue. Get Gasloine treatment to prevent storage problems and fogger to spray into the engine at winter time the last time after labor day. Follow instructions on the product lables.

Answer 3

ok, first off, i wasn't going to answer this but noone told ya. it's normal for fuel to run out of carb throat. you just turned carb. to a 45 degree angle. now, there should be an airbox covering them and bleed line from bottom of box to engine block to recover it. if it's leaking onto transom then needs repair. smoking on startup is normal due to choke system, when engine has been ran a while it should be visible but not a cloud. smoking can be a few things from worn out cyls./piston/rings. to flooding carbs, but flooding carbs will make engine run poor. you didn't mention stalling, lack of power so i'd look to old fuel, over oiling, rule of thumb for outboards, if fuel sits over 3 months it's octane is too low for proper burn. if boat is not used often then the float bowls can end up with heavy oil mix in carb. fuel evaporates and oil doesn't. rec. using cheap electric fuel pump hooked to tank fuel outlet for removal. then add fresh fuel and proper oil mix if it doesn't have auto oiler. if it has a oil res. in boat or on motor then don't put any in fuel tank. next, hook fuel line back up and remove float bowl drains and pump fuel bulb til clean fresh fuel is raining out of holes. reinstal drains, wash away fuel and dry engine. then pump er up again. now one other thing, the diaphram in mechanical fuel pump can be bad and crankcase can suck in exces fuel there and won't necessarily run bad but will smoke, same if it has a bleed style choke and solenoid won't close fully. that should just about cover it. best of luck to ya

Answer 4

you have probably got a real bad float in it,,and also it sounds like it may be flooding a little also,,you need to check the carburetor bowl gasket on it,,make sure the screws are tight ,,it may be time to rebuild all he carbs on it,,i had to do mine,,when it was 4 years old,,but it is fine now,,be care full though it can get you out,,and stall on you,,i know it happened to me good luck with it,,i hope this help.s.

Answer 5

fuel jet stuck open,not responding..check floats,smoking on a two stoke is mostly poor mix