5.7lt hard to start after a small run and 30min sit but still starts - Page 2 - Maxum Boat Owners Club

CdA Maxum · 03-30-2011, 05:52 AM

Yup, SAME problem with my 1997 2300 SR with a 5.7L carb engine. My mechanic went through the carb and found no issues yet still hard starting after running. Two things to resolve this. Do NOT shut your boat off after hard running. Let it idle down a minute before shutting off. This keeps water from backwashing into the exhaust and also lets and gets the carb from having excessive fuel dump down the cylinders. Then always give it one or two pumps before starting. This is not a fuel injected engine. You need to pump the gas just like an old muscle car. Never a problem since I took this advice.

Bella Sera 3300SCR · 03-30-2011, 12:20 PM

This thread brings back many memories of my 92' 2300SCR with a 5.7 260 carbed Merc. The engine would start fine cold then after a long run would give the same hard starting symptoms described here. My trusty mechanic form Mo Beck Stern Drive in So Cal advised me that the motor was showing signs of fuel vapor lock. He suggested that after a heated run of the motor and after coming off plane, allow the motor to cool down for a least five minutes at idle. This lessens the chance that the heated motor will boil the fuel bowl in the carb and cause FVL. Try it, it may help. Additionally run the engine compartment ventilation blower while cooling at idle and keep it running after you cut the mill for another 10 minutes to air out the engine spaces (or even lift the engine lid).

All I can say is it did help lessen the problem on my previous carbed motor. Short of upgrading to a MPI engine, it should help a lot.

Now get out there and enjoy your toy!

Bella Sera 3300SCR

fatboy.1234 · 05-08-2011, 12:37 AM

hi all ,well ive had the boat in the water for about 5 months now and i have not hat any problems since then its only a little hard to start when the boat has been left not started for a week i say bad fuel in the carby thats been sitting the week thanks ..........

slh7d · 06-01-2011, 05:50 PM

my 4.3L alpha 1 has the same issues. Basically even if I pump it a couple times, it wont start, and I end up having to "choke" it WOT to get it started. As long as it starts, I don't really care. Maybe I just need to keep the starter going more (usually only crank it 4-5 seconds probably), I just don't want to burn it out.

ss3964spd · 06-01-2011, 07:05 PM

Quote:

Originally Posted by slh7d

.....and I end up having to "choke" it WOT to get it started....

"Choking" is the act of restricting the engines' ability to take in air. The choke mechanism does this when the engine is cold. Therefore, opening the throttle to WO is not choking the engine at all. Quite the opposite in fact, opening the throttle allows the engine to get more air.

If you must open the throttle to get an already warm engine to re-start it suggests that the engine was "flooded" with too much gas. In other words, the air/gas ratio is far too rich (too much gas vs. air) for the plugs to ignite it.

An already warmed up carb'd engine, if it was only off for a few minutes, should re-start at the turn of the key without needing to pump more gas into it.

Dan