Merc 850 85 hp dumping fuel out of carbs

[kevvjr]

OK i did everything i was told to, i put the carbs back on, pump the bulb and fuel just poured out of the carbs. Now what?

 

[Chris1956]

Re: Merc 850 85 hp dumping fuel out of carbs

It sounds like the float height is incorrect, or the inlet needles are not sealing well. What year is the motor, and what parts of the carbs did you replace?

 

[Yepblaze]

Re: Merc 850 85 hp dumping fuel out of carbs

Time to pull the carbs, (again) or at least the bowl covers and replace the needle/seat assemblies.

Adjust the float levels while you are there. I believe that on many of the older models the levers that actuate the float levels should be level with bowl cover assy when held upside down. But check your manual to be sure.

Many competent mechanics can redo jobs as many times as required without a whim, second thought, or whimper till they achieve their goal.

Too many times once a job is "done" (even if done incorrectly) will not be re addressed, and a shop, or person will move on to something else.

 

[kevvjr]

Re: Merc 850 85 hp dumping fuel out of carbs

well i checked to make sure the float was level and i checked to make sure the needle was moving, but i will try it all again. im not sure on the year i think its late 70's and the only parts i replaced was the gaskets.

 

[Silvertip]

Re: Merc 850 85 hp dumping fuel out of carbs

If fuel is coming out of all of the carbs, you obviously did something wrong and the two components that control this are float adjustment and the inlet needle and seat. If you installed those upside down it won't seal. If they are binding, they won't seat correctly. It is the tab on the float that operates the needle. If that interface is incorrect the needle won't seat.

 

[Chris1956]

Re: Merc 850 85 hp dumping fuel out of carbs

The early 70s carbs will have the foam floats or the hard plastic floats. The foam ones disolve. The hard plastic floats can crack. Inspect them to see that they are in good shape. Each float has a small spring on top that pushes the inlet levers to push the needle into the seat. Check to see that the spring is present and the levers are adjusted correctly. Also, the original inlet needles were SS with brass and rubber seats. These were replaced by brass seats and ss needles with neopreme tips. The early needles wont work with the later seats.

 

[Yepblaze]

Re: Merc 850 85 hp dumping fuel out of carbs

And for the price of new needle/seats at the dealer, it makes sense to replace them.