Hard starting

[hogluvr]

While winterizing my new-to-me boat I noticed it was very hard to get started. The couple I bought it off of had told me they had trouble from time to time, their mechanic said it needed the fuel filter replaced but they hadn't gotten around to doing it. The boat would start and sputter a few seconds, then die. I did this over and over and over (taking breaks of course) until finally it started running 10, then 15 seconds, and then finally caught. Once it was warmed up it purred like a kitten. I plan on doing a full tune-up on it just because I have no idea when it was done last, but doubt that would fix the problem. I looked at online schematics and it doesn't appear that there's a fuel filter in the carb itself, just the remote-mounted filter/separator. I'm thinking maybe a choke adjustment? I definitely want to get this sorted out before I take it out in the water. Any ideas/suggestions?

 

[hogluvr]

Almost forgot, it's a 1992 Four Winns with 5.0 H.O. OMC Cobra, 2bbl. Holley carb

 

[alldodge]

While it may need a tune up and filter, I don't see the need for a filter be the cause of hard starting. Either the carb is getting gas or its not.

When boat is first going to start, see if the choke closes when the throttle is pumped. If it closes, see if there is gas squirting down the throat of the carb when its pumped.

 

[hogluvr]

Yeah it def sounds like it's starving for gas. I'll check like you said, I suspect the choke but could be a carb or even a fuel pump issue as well. Thanks for the reply.

 

[Scott Danforth]

how long is it sitting prior to firing it up?

a vented carburetor will evaporate the fuel in the bowl over a period of 2-3 weeks. it may need to crank a bit to get fuel to the carb

the only filter needed is the fuel/water filter, however as AD mentioned, it wont cause hard starting unless it was full of water.

when starting a carbureted boat, did you give it 1-2 full throttle pumps to set the choke and prime the motor, then did you use the throttle only button to bring the throttle up to about 1200 RPM?

 

[hogluvr]

It was sitting for about a month. I did give it gas before starting, being a noob to boating I did not know there was a throttle-only button? How does that work, I had to engage the drive to give it gas when running?

 

[alldodge]

To do throttle only, there is normally a button in the center of the throttle handle. Press in on the button then move throttle forward.

 

[Scott Danforth]

sitting for a month, there will be no fuel in the carb, so it will need to crank a bit to get fuel to the fuel bowls. if you have an electric pump, you may not need to crank as much.

on an omc, you pull the throttle handle out toward you. it will move about 3/8" outward. you grab the base and pull toward you

on aftermarket, VP's and Mercruisers, you press the button on the center of the throttle handle pivot.

 

[hogluvr]

Yes, I have that button in the center of the throttle, wondered what that was for! I feel like such an idiot when it comes to boating! Thanks guys for the replies.

 

[Lou C]

With the Holley 2bbl carb it will have an electric choke (see the flap on the top of the carb below) which should be closed with a cold engine and then as it starts it will open just a fraction of an inch. As the engine runs the electric heater will open it in approx 3-5 minutes. If its staying fully open (probably needs a new choke heater/spring assembly) or it closes but does not get pulled open a fraction of an inch (choke unloader not functioning) the choke unloader probably needs service.
Here's a pic of the 4 bbl version the choke will look similar. Your 2bbl will look the same but will not have the round secondary diaphragm or the rear float bowl on the left side.

 

[hogluvr]

Thanks, I'll take a look and see if the choke is open or closed when cold, give it a couple blips of the throttle and see if anything changes. That's about all I can do for now, boat is already winterized. At least it gives me something to think about.

 

[PITBoat]

I have an old truck with a 6.6L sbc that I only drive occasionally. I prime it by pouring just a little gas in the front 2 barrels before I try to start it (cpl tblspoons maybe?), along with the normal mash and release a couple times of the pedal. It always fires right off like that, and really saves the starter. I might have to do it twice since that's not enough to keep it going for long, or just floor it and release again after it dies once or twice, but it's a lot better than cranking and cranking and cranking.

Works for the boat too if it hasn't run in a while.

We had a month or so break from the boat this summer due to vacation, etc. I thought it'd be fine, but when I got it to the lake, it didn't crank as fast as it shoulda. I usually have a can of starter fluid just in case, but not that time. It finally fired off, but being ready to prime it might've saved a wasted trip.

 

[Lou C]

The gas will evaporate after a period of time and that’s what causes the extended cranking. I think changing to the newer PMGR style starters helps with this issue since they draw less amps and crank the engine over faster.