hard starting

[Thumbtack]

Mercruiser 4cyl. inline. I forget what year. It has that stupid destributorless ignition system (no coil). After it is warmed up it is hard to start, have to put the throttle all the way foward to get it to start. Comp. is good carb was rebuilt, plugs were cleaned. has a new fuel filter. any idea why this would be happening. I took the comp. reading when engine was warmed up.

 

[Haut Medoc]

Re: hard starting

Fuel problem......
Who rebuilt the carb?......
I would pull the flame arrestor off & see what is happening when this occurs......
If there is gas dribbling into the throat, something was missed on the rebuild.....​

 

[Thumbtack]

Re: hard starting

i'm kinda afraid to put my face over the carb while doing this, it has popped out of the carb a couple of times while trying to start up warm, that happens very rarely so i don't think the popping has anything to do with it. It happens maybe once out of every 10 tries to restart.
Also, if this helps. It is a two barrel with the one mixture screw, and it runs great at all RPMs.
Its like for some reason it just loads up on fuel only after it shuts down while warm. If it is cold and i shut it down it will start perfectly, same thing if i start it after a few days, it will start perfectly.

 

[Bondo]

Re: hard starting

It Sounds like the carb is Leaking internally.......

 

[Thumbtack]

Re: hard starting

put on a brand new carb now instead of that rebuild and is still doing same thing.

 

[bomar76]

Re: hard starting

You located, bought, and installed a new carb within 6 hours?

 

[Thumbtack]

Re: hard starting

i live right by a marine supply store and they say they keep one of just about every kind of carb in stock at all times.
Anyway, i was able to get the engine number because they needed it to give me the right card. Engine number is OC767698.
After putting on the new carb and it did the same thing i then tried to adjust the idle mixture screw some more, i thought i had it set good at 1 1/4 turns out but then after messing with it i found the best rpm at only 1/2 turns out. Such a small amount of turns out scares me but like i said it is the best and smoothest setting i can find. I am using a shop tach, not my boat tach and setting to 650-700 in gear.
Anyway, it still does it. However, i do think it did improve. any ideas?