1983 150 black max not reving

jbonefc3s87

Cadet
Joined
Jun 17, 2010
Messages
27
i took my boat out for the first time on Saturday. it was shaping up to be a great day, the motor fired up and held a strong idle. i putted the 3/4 miles through the no wake zone, and when i passed it I slowly gave it gas. and it was responding beautifully. i got it up on a plane messing with the trim, "its all new to me" and got a good feel for it. i kept playing with it from a stop, and getting it to plane when all the sudden it wouldn't respond passed an idle. if i give it gas it starts to bog. would anyone know what may have happened? where do i start trouble shooting?
 

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: 1983 150 black max not reving

What is the history on the motor? Has it been sitting for a while?
 

jbonefc3s87

Cadet
Joined
Jun 17, 2010
Messages
27
Re: 1983 150 black max not reving

yes it was sitting for about 4-5 years. didn't have a lower unit on it and i just got it all together. new plugs, ran it with new fuel/ oil
 

DamianJP

Chief Petty Officer
Joined
Mar 25, 2008
Messages
612
Re: 1983 150 black max not reving

Hey jbonefc3s87

Sounds like fuel delivery. Check inline fuel filter , carbs , fuel pump.
After sitting for that long I would rebuild both the fuel pump's diaphrams/gaskets and grab a carb rebuild kit aswell. Fuel filter is the easy clean.

Mabey after sitting the carbs built up some varnish/crap and was working good until the crap got sucked up into the carbs jet holes. Could be a stuck float too.
Pop the black cover off the front of the intake and look for gas overflow from the front of the carbs when it bogs down.

Also if it has a water seperater change that too.

Did you ever drain the old gas outta the tank in boat, provided the boat was sitting 4-5 years too? Sometimes crap build up there aswell on bottom and when you take some turns and slosh it around abit it will suck it up.


Lemme know,
DamianJP
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 1983 150 black max not reving

Quick check. Pull the pulse line off the fuel pump and look inside it. If it's wet, throw in a fuel pump kit, the diaphragm gave up the ghost.

If it was running good on fresh fuel and that happened, most likely.

Another thing to check quick is the fuel filter. If the primer bulb and line were decaying, it would plug up the fuel filter.


hope it helps
John
 

jbonefc3s87

Cadet
Joined
Jun 17, 2010
Messages
27
Re: 1983 150 black max not reving

just to add some information. i haven't ran it with the original tanks. i have two of those 6 gallon portable tanks, and i know the fuel was completely clean.
 

DamianJP

Chief Petty Officer
Joined
Mar 25, 2008
Messages
612
Re: 1983 150 black max not reving

Hey

Okay well that takes the contaminated gas/tank stuff outta the question. To second Martin's advice, was it new lines and primer bulb leading to fuel filter too?

Now follow J Martin's quick checks to see if you can eliminate anything else. So when you do spend money on kits and/or parts you know where to exactly funnel the funds.

Also like I said when it bogs down or at anytime, does any gas flow from the front of the carbs?

Let us know what ya find and we'll take it from there.


Thanks,
DamianJP
 

donzi gt230

Petty Officer 3rd Class
Joined
Jul 19, 2010
Messages
92
Re: 1983 150 black max not reving

Did you open the vent screw on the tank? Common oversight.
 

jbonefc3s87

Cadet
Joined
Jun 17, 2010
Messages
27
Re: 1983 150 black max not reving

yes i made sure there was plenty of ventilation. took off the vent plug completely when it started bogging. and i see a little residue when i pulled the cover to the intake. so possibly a stuck float? I dont know much about carburetors, on this v6 it would only have one carb though right? thats something i need to rebuild anyway so i will start their. where is the best place to purchase a carb rebuild kit? is this something i should let the marine mechanic do?
 

DamianJP

Chief Petty Officer
Joined
Mar 25, 2008
Messages
612
Re: 1983 150 black max not reving

Hey jbon :)

Cool, but when ya can try and recreate the symptom while watching that area to make sure that's were the residue is coming from.I'm almost certain but I don't want to give you info that wastes you time/money.

Gonna be 3 double barrel carbs.
Do you have a service manual?
Not that I'm a guru but have you worked on car/outboard carbs before?

It's abit intricate ,the brass parts require finess and the right fitting tools(thanks jmartin)the first time but I found it fun/rewarding ,especially when I cranked her up and headed to my first fishing spot that day.

As for a whole kit I couldn't find a all in one kit.But my local merc shop pieced together one.Maybe someone has link to a all in one kit.

I did my first merc carb job with the help of the people here on this forum and service manual.Jmartin helped a "ton". So as far as you doing it I say grab a manual and dig in with everyone's help here if you feel comfortable. But if not I don't want you to junk the carbs up.Might cost abit more than you doing them yourself but they will be done 100%.

By the way did you check the quick checks Jmartin mentioned, to eliminate the leading lines/bulb , fuel pump and fuel filter?

Lemme know what ya think and/or if you need help.

DamianJP
 
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