350 mercruser wont start in water.

[wez1585]

hi guys i have been beating my self for a little bit on this prob. and i cant figure out why i can start the 350 1985 mercruser with a 4 b rochester carb in the water. i can start it all day long on a hose. just a couple turns. but when i go to the water it turns and turns but no start. if i pull the bout out a little bit just enogh to have the water pick up under water it will start and then ill back it down all the way and it will idle for a little and then die down and will not restart. i have changed filters water separator and inline at carb inlet. i am lost
thanks guys.

 

[Alpheus]

Re: 350 mercruser wont start in water.

Is the boat not starting when the bow is up in the air as if on a boat ramp?

Is the drive in a different position on your trailer (when its running normal) than it is when in the water?

I would check out why its not starting in the water. lack of fuel or spark. It sounds like a fuel problem to me. Is

 

[Don S]

Re: 350 mercruser wont start in water.

Do you have the timing set to specs? Not bv ear, by using a timing light and actually makeing sure it's at the proper degrees.

 

[wez1585]

Re: 350 mercruser wont start in water.

it dosent start when is fully trimed down and the boat is floating in the water. and about the timing i havent really checked that.. ill check timing tomorrow do tou have any idea what degree is suposed to be?

 

[Don S]

Re: 350 mercruser wont start in water.

8? BTDC at 700 rpm.

 

[wez1585]

Re: 350 mercruser wont start in water.

ok i have tryed before to get the rpm to around 700-750 at idle but when i get it below 1000 it idles for a few secs and then bogs down could that be a sign of out of timing?

 

[Bondo]

Re: 350 mercruser wont start in water.

Nope,... It's a sign that the Carb is All Boogered up...