305ci / 228hp hard starting

Cresco750

Petty Officer 2nd Class
Joined
Jul 7, 2012
Messages
192
Hi all

My 1982 Mercruiser 228 has developed a tendency to be hard starting between useages. It starts absolutely fine all day once the initial start has made, but if the boat as not been used for a day of more I find that I have to keep it cranking for a good 15-20 seconds before it will fire. It will then begin to fire and kick into life a few seconds later. Once started it runs and idles sweetly. It almost seems like the automatic choke isnt functioning, but then wouldnt the engine run rough until it warmed up? Engine performance seems to be faultless once running.

The engine utilizes an electric fuel boost pump to fill the fuel line and carb bowl, and I can hear the pump come up to pressure after a few seconds of turning it on suggesting that the carb bowl is filling? I also fitted a new mechanical fuel pump approximately fifteen hours ago, but I I assume that if this was giving any grief then the engine would not run at all since I only use the electric pump as a primer.

I have not yet done any fault-finding, as I am hoping someone may be able to suggest the most logical order to do things?
Obvious things I'm thinking of include; ignition timing / plugs / points / coil / HT leads, carb accelerator pump, and engine compression, but which of these should I approach first? Some of these items I don't have the means to check myself, such as timing, so I don't want to have to pay for a mechanic to look at it if that is considered an unlikely cause.

The boat is new-to-me, having been stored for the past twelve years. In the first ten or so hours I did in the boat the engine seemed to start much easier, and its only in the last few hours that the cold starting issue has surfaced. I'm worried that I will end up burning out the starter motor and / or stuffing my new battery.

Any suggestions will be great fully received!
 

Bondo

Moderator
Staff member
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Apr 17, 2002
Messages
71,133
Re: 305ci / 228hp hard starting

Ayuh,.... After ya prime the carb, do ya pump the throttle to Wot a couple of times,..??

If not, Try it...
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 305ci / 228hp hard starting

Is the boat new to you? Have you ever run a carbed engine before?
Many young people today have no idea how to operate a carbed engine when cold.
 

beermak

Seaman
Joined
Sep 21, 2012
Messages
55
Re: 305ci / 228hp hard starting

pump it 4/5 times before cranking

then set the trottle in 20% aprox and turn key. Should crank and start if theres no ignition issues

Ive seen ppl pump like crazy and crank while pumping and just wont start.. if no success u should be checking the ignition setup of ur engine.

that way works for me and my old 350ci :rolleyes:
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: 305ci / 228hp hard starting

Are you still using fuel from warmer/cooler months? The fuel companies change the additive package in accordance with the seasons...
 

grewvin1

Petty Officer 2nd Class
Joined
Apr 2, 2012
Messages
189
Re: 305ci / 228hp hard starting

Pump to WOT couple of times, have a look and see if the choke is closed in the carb, (do not forget to replace flame arrestor) set throttle 1/4 or 20% crank for 5-8 seconds, if no start give it a sec or two, give one more full pump set throttle 1/4 or so then try again.
Carbs each have their own way you just need to find it.
 

Cresco750

Petty Officer 2nd Class
Joined
Jul 7, 2012
Messages
192
Re: 305ci / 228hp hard starting

Thanks for the replies, guys.
Yes, I do pump the throttle three two to three times and then set it for approximately the 1500-2000rpm range.

I'll check the choke first, I think. So it should automatically set to closed when cold even when the engine isn't running, ie it doesn't rely on vacuum to pull it closed once the engine is cranking?
 

Bondo

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Apr 17, 2002
Messages
71,133
Re: 305ci / 228hp hard starting

So it should automatically set to closed when cold even when the engine isn't running, ie it doesn't rely on vacuum to pull it closed once the engine is cranking?

Ayuh,.... Movin' the throttle, to Wot, sets the choke, when cold...

'n set the throttle higher when startin', 'n be ready to pull it back, when she lights...
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 305ci / 228hp hard starting

Also make sure the accelerator pump is squirting fuel when you pump the throttle. If it doesn't, then pumping the throttle is gaining you nothing. You would then need to fix the accelerator pump. AKA rebuild the carb.
 
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