150 merc wont cold idle, and shuts off alot

[TThornhill]

Hey all, 1998 150 merc 2strok carbed. Having what Im pretty sure if a fuel delivery problem. on the muffs, motor will crank right up, no problem, and stay running. once it gets in the water i have to make sure the primer bulb is tight, choke it, then have to rev it some throttle in neutral before it will fire up and stay running. then it will still die out once i put it in gear and idle, i just replaced my primer bulb (with factory equip!) and am thinking of replacing my pickup tube, replacing the anitsiphon, and all fuel hoses and maybe even rebuild the fuel pump since its so cheap to do so. also in the water the bulb will every now and then lose pressure when in just sitting with the motor off. sometimes its hard to start, im just wondering if its getting flooded, or if its starving, since i have to normally give it throttle in neutral just to crank it. am i looking in the right direction, or is there any other areas i should look. i just rebuilt the powerhead and i have good compression 130 -125 across the board. Thanks

 

[Faztbullet]

Re: 150 merc wont cold idle, and shuts off alot

First thing I would do is install a new fuel pump diaphram to insure proper fuel pressure to carbs. Since it was "rebuilt" I would closely check the sync & link and bleed lines for proper routing. Also check that the thermal air valve is working...

 

[TThornhill]

Re: 150 merc wont cold idle, and shuts off alot

as far as the sync and link, is that just to control the butterfly opening and closing, or are there some other function that does as well