3.0 140hp 1983 "cold starting"

[airshot]

I have owned my first I/O for a few months now and thanks to the fine people on this forum have worked out all the bugs except one. Cold starting..
If I use the boat on a weekly basis cold starting is not a problem, however when it sits for two or three weeks it cranks forever, gotten to the point of removing flame arrester and manually closing choke completely and it will start more quickly. Carb has been rebuilt and is adjusted to perfection to measurements in instructions. Once started, it starts easily ever after as long as more than two weeks don't pass. It seems like it takes a long time to get the fuel to the carb, tried pumping the throttle, followed the cold start instructions posted on this forum and also read the post about the primer bulb someone inserted in their fuel line. ( I considered that) once the fuel is there it runs and starts excellent. Open to suggestions ?? Thanks in advance for any help you can give.

 

[Alpheus]

Re: 3.0 140hp 1983 "cold starting"

If your choke is not closing on its own then it need adjusted so it does.

 

[airshot]

Re: 3.0 140hp 1983 "cold starting"

The choke does close on its own, but the choke pull off keeps it from closing completely, I believe the setting was for 5/64 opening for the pull off.
When I say close I mean literally close the choke plate tight and hold it there while I crank, even then it takes a little while. Thanks for the reply, any other suggestions out there?

Airshot

 

[Alpheus]

Re: 3.0 140hp 1983 "cold starting"

After the boat sits for awhile, take the flame arrestor off and have someone pump the throttle. You should see two streams of fuel squirt into the carb for at least 4 full pumps?

I know you have a 3.0 but what kind of carb does it have?

I know Rochester 4 barrel carbs have leaky well plugs but I dont know if that applies to two barrel ones. (If thats the carb you have)

Your fuel in the bowl may be leaking out over time leaving your carb as dry as a popcorn fart until the fuel pump gets the gas up there to get it started.

 

[dubs283]

Re: 3.0 140hp 1983 "cold starting"

yep, those 2 bbl rochester/mercarbs have the leak problems too

i've seen it many times - "boat runs great for the first half hour, then i shut it down and i can't get it restarted!!"

run it and check the barells after shutdown - like a kitchen faucet pouring down there

rebuild the carb and everything is all good, now time for a tune-up cuz ya know those plugs are fouled

 

[zbnutcase]

Re: 3.0 140hp 1983 "cold starting"

Depending on climate, not uncommon for fuel in carb bowl to evaporate in just a few days...and also common to have to crank engine for a bit to get fuel in there again...not saying you don't have a prob with it, but then again, you may not, especially if you are comparing this to a late fuel injected engine.

 

[airshot]

Re: 3.0 140hp 1983 "cold starting"

Now things are getting weird, cold started fine this am, of course we ran it yesterday. After it was warm, moving from one fishing spot to another, sometimes it started right up but a couple times we tried on and off for a half hour then suddenly it started like nothing was wrong. We removed the cover and checked spark and power to coil, had both, also tried pumping the gas and had a good fuel flow. Never had any gas fumes of any sort in compartment, have checked all connections for leaks many times. What about fuel pump? do they act up or just stop working? Possibility of fuel draining back into fuel tank? tank sits on level floor under seat not below floor
then hose rises follows the gunwales to the rear then drops down to the fuel pump. When it runs it runs perfect and idles right down to 600 rpm with no problems and scoots when you give it gas, it is just this annoying start issue.
Thanks again for the replys and suggestions, open to any more you have to offer.

Airshot